Wednesday, December 19, 2007

IRNSS

The Indian Regional Navigational Satellite System (IRNSS) is a developmental autonomous regional satellite navigation system that is being constructed[1] and is controlled by the Indian government. It is intended to provide an absolute position accuracy of better than 20 meters throughout India and within a region extending approximately 1,500 to 2,000 km around it. A goal of complete Indian control has been stated, with the space segment, ground segment and user receivers all being built in India. The government approved the project in May 2006, with the intention it be implemented within six to seven years. The first satellite of the proposed constellation, developed at a cost of Rupee 1,600 crore (16 billion rupees), is expected to be launched in 2009.[2] It is unclear if recent dealings with the Russian government to restore their GLONASS system will supersede the IRNSS project or feed additional technical support to enable its completion. The proposed system would consist of a constellation of seven satellites and a support ground segment. Three of the satellites in the constellation will be placed in geostationary orbit and the remaining four in geosynchronous inclined orbit of 29° relative to the equatorial plane. Such an arrangement would mean all seven satellites would have continuous radio visibility with Indian control stations. The satellite payloads would consist of atomic clocks and electronic equipment to generate the navigation signals. The navigation signals themselves would be transmitted in the S-band frequency (2-4 GHz) and broadcast through a phased array antenna to maintain required coverage and signal strength. The satellites would weigh approximately 1,330 kg and their solar panels generate 1,400 watts. The ground segment of IRNSS constellation would consist of a Master Control Center (MCC), ground stations to track and estimate the satellites' orbits and ensure the integrity of the network (IRIM), and additional ground stations to monitor the health of the satellites with the capability of issuing radio commands to the satellites (TT&C stations). The MCC would estimate and predict the position of all IRNSS satellites, calculate integrity, makes necessary ionospheric and clock corrections and run the navigation software. In pursuit of a highly independent system, an Indian standard time infrastructure would also be established.

Introduction to Photogrammetry

This brief introduction is written for non-photogrammetrists. It should give a rough overview about photogrammetry, its history, used instruments and some common techniques. It was not intended to be a complete reference. To get more detailled information, please choose an adequate publication from the Literature section.
1. What is Photogrammetry
Photogrammetry is the technique of measuring objects (2D or 3D) from photo-grammes. We say commonly photographs, but it may be also imagery stored electronically on tape or disk taken by video or CCD cameras or radiation sensors such as scanners. The results can be:
  • coordinates of the required object-points
  • topographical and thematical maps
  • and rectified photographs (orthophoto).
Its most important feature is the fact, that the objects are measured without being touched. Therefore, the term „remote sensing“ is used by some authors instead of „photogrammetry“. „Remote sensing“ is a rather young term, which was originally confined to working with aerial photographs and satellite images. Today, it includes also photogrammetry, although it is still associated rather with „image interpretation“. Principally, photogrammetry can be divided into:
  1. Depending on the lense-setting:
    • Far range photogrammetry (with camera distance setting to indefinite), and
    • Close range photogrammetry (with camera distance settings to finite values).
  2. Another grouping can be
    • Aerial photogrammetry (which is mostly far range photogrammetry), and
    • Terrestrial Photogrammetry (mostly close range photogrammetry).
The applications of photogrammetry are widely spread. Principally, it is utilized for object interpretation (What is it? Type? Quality? Quantity) and object measurement (Where is it? Form? Size?). Aerial photogrammetry is mainly used to produce topographical or thematical maps and digital terrain models. Among the users of close-range photogrammetry are architects and civil engineers (to supervise buildings, document their current state, deformations or damages), archaeologists, surgeons (plastic surgery) or police departments (documentation of traffic accidents and crime scenes), just to mention a few.
2. Brief History of Photogrammetry
1851: Only a decade after the invention of the „Daguerrotypie“ by Daguerre and Niepce, the french officer Aime Laussedat develops the first photogrammetrical devices and methods. He is seen as the initiator of photogrammetry. 1858: The German architect A. Meydenbauer develops photogrammetrical techniques for the documentation of buildings and installs the first photogrammetric institute in 1885 (Royal Prussian Photogrammetric Institute). 1866: The Viennese physicist Ernst Mach publishes the idea to use the stereoscope to estimate volumetric measures. 1885: The ancient ruins of Persepolis were the first archaeological object recorded photogrammetrically. 1889: The first German manual of photogrammetry was published by C. Koppe. 1896: Eduard Gaston and Daniel Deville present the first stereoscopical instrument for vectorized mapping. 1897/98: Theodor Scheimpflug invents the double projection. 1901: Pulfrich creates the first „Stereokomparator“ and revolutionates the mapping from stereopairs. 1903: Theodor Scheimpflug invents the „Perspektograph“, an instrument for optical rectification. 1910: The ISP (International Society for Photogrammetry), now ISPRS, was founded by E. Dolezal in Austria. 1911: The Austrian Th. Scheimpflug finds a way to create rectified photographs. He is considered as the initiator of aerial photogrammetry, since he was the first succeeding to apply the photogrammetrical principles to aerial photographs. 1913: The first congress of the ISP was held in Vienna. until 1945: development and improvment of measuring (=„metric“) cameras and analogue plotters. 1964: First architectural tests with the new stereometric camera-system, which had been invented by Carl Zeiss, Oberkochen and Hans Foramitti, Vienna. 1964: Charte de Venise. 1968: First international Symposium for photogrammetrical applications to historical monuments was held in Paris - Saint Mandé. 1970: Constitution of CIPA (Comité International de la Photogrammétrie Architecturale) as one of the international specialized committees of ICOMOS (International Council on Monuments and Sites) in cooperation with ISPRS. The two main activists were Maurice Carbonnell, France, and Hans Foramitti, Austria. 1970ies: The analytical plotters, which were first used by U. Helava in 1957, revolutionate photogrammetry. They allow to apply more complex methods: aerotriangulation, bundle-adjustment, the use of amateur cameras etc. 1980ies: Due to improvements in computer hardware and software, digital photogrammetry is gaining more and more importance. 1996: 83 years after its first conference, the ISPRS comes back to Vienna, the town, where it was founded.
3. Short description of photogrammetrical techniques
Dot 3.1. Photographing Devices A photographic image is a „central perspective“. This implies, that every light ray, which reached the film surface during exposure, passed through the camera lens (which is mathematically considered as a single point, the so called „perspective center“). In order to take measurements of objects from photographs, the ray bundle must be reconstructed. Therefore, the internal geometry of the used camera (which is defined by the focal length, the position of the principal point and the lens distortion) has to be precisely known. The focal length is called „principal distance“, which is the distance of the projection center from the image plane´s principal point. Depending on the availability of this knowledge, the photogrammetrist devides photographing devices into three categories: 3.1.1. Metric cameras They have stable and precisely known internal geometries and very low lens distortions. Therefore, they are very expensive devices. The principal distance is constant, which means, that the lens cannot be sharpened when taking photographs. As a result, metric cameras are only usable within a limited range of distances towards the object. The image coordinate system is defined by (mostly) four fiducial marks, which are mounted on the frame of the camera. Terrestrial cameras can be combined with tripods and theodolites. Aerial metric cameras are built into aeroplanes mostly looking straight downwards. Today, all of them have an image format of 23 by 23 centimeters. 3.1.2. Stereometric camera If an object is photographed from two different positions, the line between the two projection centers is called „base“. If both photographs have viewing directions, which are parallel to each other and in a right angle to the base (the so called „normal case“), then they have similar properties as the two images of our retinas. Therefore, the overlapping area of these two photographs (which are called a „stereopair“) can be seen in 3D, simulating man´s stereoscopic vision. In practice, a stereopair can be produced with a single camera from two positions or using a stereometric camera. A stereometric camera in principle consists of two metric cameras mounted at both ends of a bar, which has a precisely measured length (mostly 40 or 120 cm). This bar is functioning as the base. Both cameras have the same geometric properties. Since they are adjusted to the normal case, stereopairs are created easily. 3.1.3. „Amateur“ cameras The photogrammetrist speaks of an „amateur camera“, when the internal geometry is not stable and unknown, as is the case with any „normal“ commercially available camera. However, also these can be very expensive and technically highly developed professional photographic devices. Photographing a test field with many control points and at a repeatably fixed distance setting (for example at infiniy), a „calibration“ of the camera can be calculated. In this case, the four corners of the camera frame function as fiducials. However, the precision will never reach that of metric cameras. Therefore, they can only be used for purposes, where no high accuracy is demanded. But in many practical cases such photography is better than nothing, and very useful in cases of emergency. Dot 3.2. Photogrammetric Techniques Depending on the available material (metric camera or not, stereopairs, shape of recorded object, control information...) and the required results (2D or 3D, accuracy...), different photogrammetric techniques can be applied. Depending on the number of photographs, three main-categories can be distinguished. 3.2.1. Mapping from a single photograph Only useful for plane (2D) objects. Obliquely photographed plane objects show perspective deformations which have to be rectified. For rectification exists a broad range of techniques. Some of them are very simple. However, there are some limitations. To get good results even with the simple techniques, the object should be plane (as for example a wall), and since only a single photograph is used, the mappings can only be done in 2D The rectification can be neglected, only if the object is flat and the picture is made from a vertical position towards the object. In this case, the photograph will have a unique scale factor, which can be determined, if the length of at least one distance at the object is known. Very shortly, we will describe now some common techniques:
  • Paper strip method This is the cheapest method, since only a ruler, a piece of paper with a straight edge and a pencil are required. It was used during the last century. Four points must be identified in the picture and in a map.From one point, lines have to be drawn to the others (on the image and the map) and to the required object point (on the image). Then the paper strip is placed on the image and the intersections with the lines are marked. The strip is then placed on the map and adjusted such that the marks coincide again with the lines. After that, a line can be drawn on the map to the mark of the required object point. The whole process is repeated from another point, giving the object-point on the map as intersection of the two object-lines.
  • Optical rectification Is done using photographic enlargeners. These should fulfill the so called „Scheimpflug condition“ and the „vanishing-point condition“. Again, at least four control points are required, not three on one line. The control points are plotted at a certain scale. The control point plot is rotated and displaced until two points match the corresponding object points from the projected image. After that, the table has to be tilted by two rotations, until the projected negative fits to all control points. Then an exposure is made and developed.
  • Numerical rectification Again, the object has to be plane and four control points are required. At the numerical rectification, the image coordinates of the desired object-points are transformed into the desired coordinate system (which is again 2D). The result is the coordinates of the projected points. Differential rectification If the object is uneven, it has to be divided into smaller parts, which are plane. Each part can then be rectified with one of the techniques shown above. Of course, also even objects may be rectified piecewise, differentially. A prerequisite for differential rectification is the availability of a digital object model, i.e. a dense raster of points on the object with known distances from a reference plane; in aerial photogrammetry it is called a DTM (Digital Terrain Model).
  • Monoplotting This technique is similar to the numerical rectification, except that the coordinates are here transformed into a 3D coordinate system. First, the orientation elements, that are the coordinates of the projection center and the three angles defining the view of the photograph, are calculated by spatial resection. Then, using the calibration data of the camera, any ray, that came from the archaeological feature through the lense onto the photograph can be reconstructed and intersected with the digital terrain model.
  • Digital rectification The digital rectification is a rather new technique. It is somehow similar to „monoplotting“. But here, the scanned image is transformed pixel by pixel into the 3D real-world coordinate system. The result is an orthophoto, a rectified photograph, that has a unique scale.
3.2.2. Stereophotogrammetry As the term already implies, stereopairs are the basic requirement, here. These can be produced using stereometric cameras. If only a single camera is available, two photographs can be made from different positions, trying to match the conditions of the „normal case“. Vertical aerial photographs come mostly close to the „normal case“. They are made using special metric cameras, that are built into an aeroplane looking straight downwards. While taking the photographs, the aeroplane flies over a certain area in a meandric way, so that the whole area is covered by overlapping photographs. The overlapping part of each stereopair can be viewed in 3D and consequently mapped in 3D using one of following techniques:
  • Analogue The analogue method was mainly used until the 70ies of our century. Simply explained, the method tries to convert the recording procedure. Two projectors, which have the same geometric properties as the used camera (these can be set during the so called „inner orientation“), project the negatives of the stereopair. Their positions then have to be exactly rotated into the same relationship towards each other as at the moment of exposure (=„relative orientation“). After this step, the projected bundle of light rays from both photographs intersect with each other forming a (three dimensional optical) „model“. At last, the scale of this model has to be related to its true dimensions and the rotations and shifts in relation to the mapping (world) coordinate system are to be determined. Therefore, at least three control points, which are not on one straight line, are required (=„absolute orientation“). The optical model is viewed by means of a stereoscope. The intersection of rays can then be measured point by point using a measuring mark. This consists of two marks, one on each photograph. When viewing the model, the two marks fuse into a 3D one, which can be moved and raised until the desired point of the 3D object is met. The movements of the mark are mechanically transmitted to a drawing device. In that way, maps are created.
  • Analytical The first analytical plotters were introduced in 1957. From the 1970ies on, they became commonly available on the market. The idea is still the same as with analogue instruments. But here, a computer manages the relationship between image- and real-world coordinates. The restitution of the stereopair is done within three steps: After restoration of the "inner orientation", where the computer may now also correct for the distortion of the film, both pictures are relatively oriented. After this step, the pictures will be looked at in 3D. Then, the absolute orientation is performed, where the 3D model is transferred to the real- world coordinate system. Therefore, at least three control points are required. After the orientation, any detail can be measured out of the stereomodel in 3D. Like in the analogue instrument, the model and a corresponding measuring mark are seen in 3D. The movements of the mark are under your control. The main difference to the former analogue plotting process is that the plotter doesn´t plot any more directly onto the map but onto the monitors screen or into the database of the computer. The analytical plotter uses the computer to calculate the real-world coordinates, which can be stored as an ASCII file or transferred on-line into CAD-programs. In that way, 3D drawings are created, which can be stored digitally, combined with other data and plotted later at any scale.
  • Digital Digital techniques have become widely available during the last decade. Here, the images are not on film but digitally stored on tape or disc. Each picture element (pixel) has its known position and measured intensity value, only one for black/white, several such values for colour or multispectral images.
3.2.3. Mapping from several photographs This kind of restitution, which can be done in 3D, has only become possible by analytical and digital photogrammetry. Since the required hard- and software is steadily getting cheaper, it´s application fields grow from day to day. Here, mostly more than two photographs are used. 3D objects are photographed from several positions. These are located around the object, where any object-point should be visible on at least two, better three photographs. The photographs can be taken with different cameras (even „amateur“ cameras) and at different times (if the object does not move).
  • technique As mentioned above, only analytical or digital techniques can be used. During all methods, first a bundle adjustment has to be calculated. Using control points and triangulation points the geometry of the whole block of photographs is reconstructed with high pecision. Then the image coordinates of any desired object-point measured in at least two photographs can be intersected. The result are the coordinates of the required points. In that way, the whole 3D object is digitally reconstructed.
COURTESY:http://www.univie.ac.at/Luftbildarchiv/wgv/intro.htm

GIS DEGREES IN CANADA

Canadian Graduate and Post-Graduate Geography and GIS Programs

  1. Carleton University - Geography and Environmental Studies
  2. McGill University - Geography
  3. McMaster University - Geography and Geology
  4. Memorial University of Newfoundland - Masters in Geography
  5. Memorial University of Newfoundland - Masters/PhD in Geography
  6. Queen's University - Geography
  7. Ryerson University - Spatial Analysis
  8. Simon Fraser University - Geography
  9. Simon Fraser University - Geography
  10. University of British Columbia - Geography
  11. University of Guelph - Geography MA, MSc, PhD
  12. University of Northern British Columbia - Natural Resources and Environmental Studies, MA (Geography, Environmental Studies, Tourism)
  13. University of Northern British Columbia - Natural Resources and Environmental Studies, MSc (Biology, Environmental Science, Forestry, Geography, Recreational Resource Management)
  14. University of Ottawa - Geography
  15. University of Ottawa - Geography (PhD)
  16. University of Regina - Geography
  17. University of Saskatchewan - Geography
  18. University of Toronto - Physical Geography and Natural Systems
  19. University of Toronto - Historical/Social/Cultural Geography
  20. University of Toronto - Urban/Economic Geography
  21. University of Toronto - Spatial Information Systems (GIS/LIS)
  22. University of Toronto - Environmental Geography and Resource Management
  23. University of Toronto - Geography
  24. University of Toronto - Spatial Analysis
  25. University of Victoria - Geography
  26. University of Waterloo - Geography
  27. University of Western Ontario - Geography
  28. Wilfrid Laurier University - Geography
  29. York University - Geography

ESRI's ArcPad 7.1

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ESRI's ArcPad 7.1

New Version Improves Mobile Productivity in the Field with Enhanced Tools

Redlands, California—ArcPad 7.1 and ArcPad Application Builder 7.1, the latest versions of ESRI's mobile GIS software for data collection and field mapping applications, have been released. The new enhancements in ArcPad 7.1 will help experienced users, as well as field personnel new to GIS, capture field data quickly and easily.

ArcPad products are designed for various industries and organizations wanting to extend the benefits of GIS from the office to the field. Together with ArcPad Application Builder, the development and customization framework for ArcPad, version 7.1 continues to simplify the field data collection process and offers advanced functionality for mobile users who need to make critical decisions in the field.

ArcPad provides mapping, GIS, and GPS integration to users via handheld mobile devices. It can be easily customized for specific field projects using ArcPad Application Builder. ArcPad software also integrates with ESRI desktop technologies, allowing field edits to be incorporated through disconnected editing.

In version 7.1, the ArcPad object model has been updated to support data relationship rules and includes improved data management tools. ArcPad Application Builder 7.1, sold separately, has been enhanced to include ArcPad database files and custom query forms and enables users to set "read only" layers.

ArcPad 7.1 introduces the following enhancements:

  • Much-anticipated, out-of-the-box solutions to view and edit relational databases in the field
  • QuickProject—A simple data template to capture various geographic features and help both new and experienced users become immediately productive
  • StreetMap extension—Includes the most recent North American street map data from Tele Atlas, providing geocoding, routing functionalities, and a preconfigured basemap for users at no additional cost
  • Enhanced query capabilities—Includes a query builder and query forms that support predefined, customized queries
  • ArcPad Data Manager extension for ArcGIS Desktop—Interactive tools in ArcMap and ArcPad that allow simple automation of field workflows and easier management of mobile GIS project deployments

To try a fully functional evaluation copy of ArcPad 7.1, visit www.esri.com/arcpad. The ArcPad Application Builder 7.1 update will be shipped automatically to customers who are current on maintenance without additional cost. Users who have purchased ArcPad 7.0.1 since October 22, 2007, will be eligible for a free upgrade to ArcPad 7.1.

For more information on ArcPad and ArcPad Application Builder, visit www.esri.com/arcpad. Users outside the United States should contact their ESRI international distributor (www.esri.com/international).

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Press Information: Matthew DeMeritt, ESRI Tel.: 909-793-2853, extension 1-2930 E-mail (press only): press@esri.com General Information: info@esri.com

COURTESY:http://www.esri.com/news/releases/07_4qtr/mobile.html

RADARSAT-2 Successfully Launched

Richmond, B.C. – MacDonald Dettwiler and Associates Ltd (MDA) announced the successful launch and deployment of RADARSAT-2, Canada’s next–generation commercial Synthetic Aperture Radar (SAR) satellite. The satellite was launched from the Baikonur Cosmodrome in Kazakhstan at ~ 05:17 Pacific Standard Time on a Soyuz launch vehicle.

In addition to guaranteeing data continuity for RADARSAT-1 users, RADARSAT-2 offers new capabilities with its advanced technical design. These new capabilities include: a finer resolution, flexibility in selection of polarization and left-and right-looking imaging. These capabilities, in concert with increased on-time imaging capacity, and an enhanced ground segment, allow MDA to offer clients an even greater degree of flexibility in choice of products and service offerings.

RADARSAT-2 is the product of a unique partnership between the Canadian Space Agency (CSA) and MDA. MDA is responsible for the marketing and distribution of the data via a global network of partners and ground receiving stations.

“We are extremely excited to welcome this new chapter in SAR imaging,” said John Hornsby, General Manager for MDA’s Geospatial Services business area. Dr. Hornsby continued, “RADARSAT-2 promises to deliver products with higher resolution and information content and with a significantly shorter end-to-end “order to delivery” process.”

RADARSAT-2’s successful launch is the culmination of many years of effort by MDA, CSA and its partners. RADARSAT-2 will provide enhanced information for applications such as environmental monitoring, ice mapping, resource mapping, disaster management and marine surveillance.

COURTESY: http://www.radarsat2.info/outreach/innews/2007/12142007_gsi.asp

TRENDS IN GIS

UNIT 25 - TRENDS IN GIS Compiled with assistance from Jack Dangermond, ESRI This unit reviews some of the current trends in GIS. This unit, in particular, will date very quickly. You will need to read the current trade magazines to see what the newest trends are. UNIT 25 - TRENDS IN GIS Compiled with assistance from Jack Dangermond, ESRI A. INTRODUCTION * this unit discusses o trends in computer hardware and software for GISs o new applications of GIS technology o new sources of data B. HARDWARE Fast geoprocessing * computing power is often measured in MIPS o Million Instructions Per Second * MIPS measures oversimplify the measurement of computing power but are nevertheless useful as broad bases for comparison o arithmetic calculations can require execution of as little as two and as many as 100 instructions o arithmetic on real numbers is better measured in MFLOPS ("megaflops") or millions of floating point (i.e. decimal) operations per second o MIPS="meaningless information processing statistics" * current personal computers and workstations used for GIS range from 1 to 5 MIPS * within the next five years, 20 to 30 MIPS workstations are likely at roughly similar prices o the power of personal workstations is currently increasing by close to a factor of 2 per year * workstations will likely be coupled to 1,000 MIPS file servers which can extract software and data at high speed for analysis in personal workstations * over the next decade, 1,000 MIPS machines will become common in large organizations * to this point, advances in computing power have always found new areas of application. What new applications of GIS will take advantage of higher speeds? o larger data sets, higher levels of spatial resolution o more complex models o more complex analysis for decision-making o better methods of display and visualization Parallel Processing * trend toward different computer architectures o away from single processors operating on data in sequence o parallel processors can perform tasks on several different processors simultaneously within the same computer * what GIS processes will be suitable for parallel processing? o analyses which require repeating the same steps everywhere on the map o easier to see applications for raster data than for vector since each pixel is independent o e.g. finding route for a vehicle across a rugged terrain o e.g. image processing applications such as image classification, visualization, scene generation Memory * trend is toward lower costs for ever larger computer memories o cost of storing large GIS datasets will come down o more data can be placed "on-line" for faster access * the nature of geographical data (high volume, infrequent update) is suitable for optical storage o once written, cannot be changed o CD-ROM - 5 1/4 inch disks with 250 MBytes, enough to store all streets in Los Angeles o once a "master" has been created, the unit cost of CD-ROM data is only about $10 o optical WORM - 12 inch disks with 2 GBytes, enough for the contents of 100 topographic maps * erasable optical disk is available (e.g. NEXT computer) o very high density of data Workstations * "dumb" terminals connected to a central processor are gradually being eliminated in favor of desk top computers * especially popular are "workstations", which have excellent graphic performance and sophisticated user interfaces o the exact distinction between personal computers and workstations is unclear o workstations are generally more powerful o workstations are generally more expensive ($10,000 vs. $4,000) o workstations generally use UNIX operating system rather than DOS o workstations have more powerful graphics capabilities (1280x1024 rather than 640x480) o originally, workstations developed for the scientific and engineering market * workstations function effectively as nodes on a network devoted to GIS processing o a large CPU (a fileserver) for database management and centralized processing may still be required as part of the network, while most processing is done at individual workstations o data can be distributed around the disks on the network Networks * the dominant hardware system architecture of recent years, the multiuser host, is giving way to multiuser network architectures o the network integrates compute servers, file servers, workstations and shared peripherals o any user can access data, peripherals across the network o the network will likely be linked to other networks through "gateways" * this architecture requires fast and economical data transfer and the availability of powerful workstations o data transfer rates of MBytes/second are common at low cost o only hundreds of bytes per second were possible 15 years ago o this change of cost has had enormous impact on the ways people organize computing * hardware manufacturers are beginning to offer network architectures, and networking among hardware of different vendors is likely to become more available over time o requires interchangeability of parts; standards for communication, data and software; common operating systems * this will lead to reduction in the power of data processing centers in favor of "information management" systems based on control of transactions o the role of the "computer center" based on a large mainframe is changing rapidly Hardware for specialized processing functions * compute servers, file servers, sort servers (e.g. TRW's Fast Data Finder) and search servers (e.g. Excel's Sorting Engine) are now being developed for networks o these are specialized computers attached to networks for specific functions o map overlay using hardware intersecting tools will be developed in the future, perhaps other GIS functions as well * this trend will continue since such hardware tools can provide enhanced system performance for the entire network Operating systems * continued diversity is likely for the immediate future * UNIX is making gains, perhaps especially in inexpensive machines, and in scientific and engineering applications, but is it likely to become universally supported? * this will make software development and networking more difficult, and puts a premium on GIS software, database management systems, and applications which can work on different vendors' machines Peripheral devices * excellent raster devices are now available (e.g., electrostatic and laser printer/plotters) for graphic/cartographic output o costs of these systems are directly related to the size of the product * scanning has not taken over from digitizing in GIS applications, and is unlikely to do so until some means, perhaps artificial intelligence, can be applied to separating extraneous information Specialized workstations * a data entry device is needed which will allow correction of data as they are acquired o will probably have a large flat display, multiple graphic memory planes, and interactive data capture capabilities o the workstation should be able to "check-out" and "check-in" work areas (e.g. mapsheets) from the larger database maintained by a server on the network * an "electronic sandbox" will be useful for interactive, GIS-based analysis/modeling and land use planning o the design of this workstation will require some very creative thinking * workstations specialized for particular uses (e.g., land planning, water resources, forestry) are likely to be developed as the number of users increases in such specialized fields o analyzing data on the globe (e.g. oceans, atmosphere) will require a specialized workstation which can display data on the globe's curved surface o e.g. the globe could be "browsed" using a track-ball to rotate the image * as GIS becomes a standard decision support technology, entire conference rooms will be devoted to its use o containing specialized GIS workstations, large GIS display devices, and GIS planning/conference tables C. SOFTWARE Database management systems * while present DBMS's are effective for managing tabular data, they are not effective for the "long transactions" required when cartographically referenced and topologically related data are altered o such "long transactions" occur because simple changes in cartographically referenced data may require changes in topologically related items, and because the whole process of updating geographic information differs from updating tabular data * transactions on geographical data could be confined to a single specialized workstation * queries and analysis typically do not modify the data, so these are easier to execute across the network, e.g. between a workstation and a central fileserver Relational DBMSs * trend toward using relational DBMSs (often with SQL style user interfaces), because of their "open architecture" o it is becoming easier to exchange one DBMS for another within a GIS * object-oriented database structures are being proposed for GIS use, but they present some problems o e.g. they are not well adapted to storing natural feature information o not well suited to complex spatial analysis o often have embedded proprietary data structures DBMS versus Fourth Generation Languages * the DBMS approach often involves highly structured application programming, often at the expense of ad hoc query capabilities o user must learn complex rules of syntax o may be a valid approach for static databases which are only used for simple, repetitive queries * the trend in GISs is toward the use of Fourth Generation Languages (4GLs) which provide commands, tools, procedures, and report writers to permit easy ad hoc querying of a database o these provide intelligent interfaces close to natural language, however, definitions become vague, less rigorous o use of 4GL may detract from the GISs ability to perform complex analysis GIS system integration * the marketplace increasingly demands compatibility between diverse hardware and GIS software * at the same time, GIS software needs to interface to an increasing diversity of DBMSs, because different applications often require different DBMSs o in many applications, records are already stored in a DBMS o when the GIS capability is added to allow geographical access to these records, it must interface with the existing DBMS Display products * improved cartographic products are certain, since there is both intense user demand and the technology required to support such improvements o map output will continue to be judged against hand- made products * 3D displays, overlaid with both cartographic data and representations of the built environment, are likely early developments in GIS technology o but major questions remain about how to gather, compile, model and structure 3D data o because of these problems, it is not clear what kinds of analysis are needed or appropriate for 3D data Interfaces to other technologies * interfaces between GIS, CADD, remote sensing, image processing, architectural graphics, and other technologies are going to be increasingly easy to create * the differing data types produced by these technologies will be more frequently combined in shared databases User interfaces * more sophisticated, flexible and well managed graphic user interfaces are inevitable * users are becoming increasingly impatient with software which requires any training or support from the vendor o training and support add high and probably continuing costs to GIS acquisitions D. NEW APPLICATIONS OF GIS TECHNOLOGY * because GIS technology is becoming more affordable, more reliable, more widely used and better known, new applications of GIS technology are likely to rapidly increase, just as the applications of computer graphics have increased Modeling and decision support * Geographic Information Modeling System (GIMS) technology will be developed and used in providing decision support in a growing number of fields * e.g. current interest in GIS applications in transportation planning, requires some modifications to standard GIS models, addition of new functions o e.g. modifications to allow lines which cross but do not intersect o e.g. functions to measure distances between objects via the network o e.g. functions to solve standard problems in transportation, such as predicting traffic flows * can applications in areas as different as transportation planning and forestry be served by the same GIS software? o will there be fragmentation of the GIS field by area of application? Sciences and mathematics * GIS technology will be applied widely in the sciences in the near and middle term future o e.g. 3D capabilities for geology, geophysics, hydrology, mining o GIS modeling in landscape ecology * in the longer term, applications for GIS technology may develop in areas of image processing, e.g. X-rays, other types of medical imaging, where superimposition of data, analysis may have similar importance * global issues - tropical deforestation, acid rain, greenhouse effects, endangered and threatened species, and similar problems are likely to be analyzed using GIS technology in the 1990s o GIS networks, similar to the global weather monitoring and prediction network, may evolve o they will probably make use of super computers, parallel processing, and artificial intelligence to cope with the massive databases and the complex models involved o such models are currently in very rudimentary form, e.g. global climate models used to predict greenhouse warming effects use very large cell sizes (5 degrees lat/long) o GISs will play a role in managing the global environment, perhaps used to identify the world's most sensitive habitats; then a country's agreement to conserve these habitats may be exchanged for forgiveness of international debts E. NEW SOURCES OF DATA Remote sensing * following Landsat, ERTS, Thematic Mapper and now EOS, and competing with them to supply the demand for satellite- borne imaging systems are the SPOT system and systems which the Japanese, Russians, and others may bring on line in the 1990s * as data resolution increases, costs fall, service becomes more reliable, and user demand increases, satellite remote sensing will become more important in supplying data for GIS use o already the supply of data vastly exceeds our ability to analyze it o better methods of scanning, archiving large amounts of data will be needed * remote sensing cannot provide the information required for many kinds of analyses o in the longer term (and with such new technologies as the fabrication of ultraminiature sensing devices on silicon chips), the trend will be toward "an instrumented universe" o instruments to monitor the globe will be broadcast over the earth, probably telemetering their information to networks of users Error/uncertainty * as more data and more forms of data are gathered, and there is increased pressure to combine these data for analyses, increasing attention will have to be paid to data error and uncertainty Data sharing * essential to reduce costs, solve widespread problems, and fully utilize available technology * security considerations, political divisions, and other factors will continue to inhibit sharing * because problems will increasingly be recognized as crossing international boundaries and having global implications, and because the necessary technology is now becoming available, more global databases will be built * in some situations, private businesses will compete with government agencies in supplying data to both government and the public o questions will increase about how to best serve the public interest in such cases o data gathering by government will always be under fire because of its cost F. CONCLUSION * the immediate future will be a time of explosive growth in the development and use of GIS technology o the signs are that current growth rates will continue * it is very likely that these predictions about the period will prove to have been too conservative o predictions about the value of technological change often prove to be totally wrong o e.g. the development of microchip technology which was the key to cheap computers was driven first by the need to save space and weight in space vehicles REFERENCES Dangermond, Jack and Morehouse, Scott. 1987. "Trends in Hardware for Geographic Information Systems," Proceedings AUTOCARTO 8, ASPRS/ACSM, Falls Church, VA. (Also available from ESRI) Dangermond, Jack, 1987. "Trends in Geographic Information Systems Software," Proceedings IGIS: The Research Agenda, NASA, Washington, DC. (Also available from ESRI) U.K. Department of the Environment, 1987. Handling Geographic Information, Report of the Committee of Enquiry chaired by Lord Chorley (the "Chorley Report"), Her Majesty's Stationery Office, London. DISCUSSION/EXAMINATION QUESTIONS 1. Imagine a few important future developments which you believe ought to occur in GIS technology. Do they depend chiefly on hardware or software, or both? Explain. 2. Select a particular discipline, field, or specialty to which you think GIS technology might be applied. Discuss some specific future applications and their implications for professional practice in that field. What specialized GIS features would these applications require? 3. What are the characteristics of an "ideal" source of data for use in a GIS? List them and discuss each one. Now, are there any potential sources of GIS data which have not yet been utilized but which meet most of these criteria? 4. Design a GIS workstation for the support of global science (i.e. the analysis and modeling of data for the entire globe). What operations, database models and user interface features would it have? COURTESY:http://www.geog.ubc.ca/courses/klink/gis.notes/ncgia/u25.html#SEC25.2.6

HISTORY OF REMOTE SENSING

Beyond the primitive methods of remote sensing our earliest ancestors used (ex.: standing on a high cliff or tree to view the landscape), the modern discipline arose with the development of flight. The balloonist G. Tournachon (alias Nadar) made photographs of Paris from his balloon in 1858. The first tactical use was during the civil war. Messenger pigeons, kites, rockets and unmanned balloons were also used for early images. With the exception of balloons, these first, individual images were not particularly useful for map making or for scientific purposes.

Systematic aerial photography was developed for military surveillance and reconnaissance purposes beginning in World War I and reaching a climax during the Cold War with the use of modified combat aircraft such as the P-51, P-38, RB-66, F4-C and the SR-71 or specifically designed collection platforms such as the U2/TR-1, A-5 and the OV-1 series both in overhead and stand-off collection. A more recent development is that of increasingly smaller sensor pods such as those used by law enforcement and the military, in both manned and unmanned platforms. The advantage of this approach is that this requires minimal modification to a given airframe. Later imaging technologies would include Infra-red, conventional, doppler and synthetic aperture radar

The development of artificial satellites in the latter half of the 20th century allowed remote sensing to progress to a global scale as of the end of the cold war. Instrumentation aboard various Earth observing and weather satellites such as Landsat, the Nimbus and more recent missions such as RADARSAT and UARS provided global measurements of various data for civil, research, and military purposes. Space probes to other planets have also provided the opportunity to conduct remote sensing studies in extra-terrestrial environments, synthetic aperture radar aboard the Magellan spacecraft provided detailed topographic maps of Venus, while instruments aboard SOHO allowed studies to be performed on the Sun and the solar wind, just to name a few examples.

Recent developments include, beginning in the 1960s and 1970s with the development of image processing of satellite imagery. Several research groups in Silicon Valley including NASA Ames Research Center, GTE and ESL Inc. developed Fourier transform techniques leading to the first notable enhancement of imagery data.

The introduction of online web services for easy access to remote sensing data in the 21st century (mainly low/medium-resolution images), like Google Earth, has made remote sensing more familiar to the big public and has popularized the science. COURTESY:http://en.wikipedia.org/wiki/Remote_sensing

Tuesday, December 18, 2007

Vehicle Tracking System

Currently we are working on development of Vehicle Tracking System where in the user will be able to track his vehicle online. A vehicle owner who wants to keep a track of his vehicle in terms of its location will be able to do so by logging onto the site, where he will be provided with the detailed information about the vehicle on a map with its location,speed,time etc. A vehicle black box (VBB) with the GPS unit will be fitted inside the vehicle which will not only help in online tracking but will also enhance the vehicle security due to its inherent characteristics. For further details about VBB go to http://www.microvbb.net Courtesy:http://www.microgis.net/currentproject.asp

Sunday, December 9, 2007

GIS Universities

  1. Eastern Washington University
  2. ESRI India Authorised Learning Centre
  3. Curtin University of Technology, Department of Spatial Sciences
  4. University of Tehran
  5. Southwestern College GIS
  6. Kingston Centre for GIS
  7. UNIGIS - Jagiellonian University
  8. Jagiellonian University
  9. UW-Madison Geography Department
  10. CSUN Geography Department
  11. Nothern Illinois University
  12. Jamia Millia Islamia University, India-
  13. Western Wisconsin Technical College
  14. Sir Sandford Fleming College, Geomatics Institute, Canada
  15. University of Cambridge, Department of Geography
  16. University at Albany, SUNY Dept of Geography
  17. West Virginia Unviersity, Dept of Geography
  18. Clark University IDCE GIS Program
  19. University of Wisconsin - Stevens Point Dept of Geography
  20. University of Calgary GIS Masters Program
  21. Portland State University Graduate Certificate in GIS
  22. Virginia Tech Center for Geospatial Information Technology
  23. Ball State University Department of Geography
  24. University of Vienna - Department of Geography and Regional Reserach
  25. CMU Center for GIS
  26. University of Washington - GIS Certificate Program
  27. Eastern Michigan University
  28. GIS Lab, University of Minnesota-Duluth
  29. University of Szeged, Hungary
  30. Okanagan University College
  31. Department of Geography, The University of Tennessee, Knoxville
  32. University of Central Florida, Orlando
  33. University Of Pittsburgh - Pro-MS GIS/RS
  34. West Chester University of Pennsylvania
  35. Mesa Community College GIS Program
  36. Department of Geography GIS Program, Indiana University Purdue University
  37. Department of Cartography, GIS and Remote Sensing of Comenius University, Bratislava
  38. Institute of Geoinformatics, VSB-TU Ostrava
  39. University of Arizona School of Renewable Natural Resources
  40. International Institute for GeoInformation Science & Earth Observation (ITC), NL
  41. Department of Geography, California State University, Long Beach
  42. METU Geodetic and Geographic Information Technologies
  43. Universidad Rafael Urdaneta
  44. South Dakota State University Geography Department
  45. Iowa Lakes Community College GIS Program
  46. Salem State College
  47. Texas A&M University-Corpus Christi
  48. University of Maryland Department of Geography
  49. MS in GIS at the University of Redlands
  50. Mangalore University, India
  51. University of Texas at Dallas
  52. Saskatchewann Institute for Applied Science and Technology - GIS Certificate Program
  53. Technikum K”rnten, Villach, Austria
  54. Colorado State University (Fort Collins) Remote Sensing/GIS Program
  55. Southwest Texas State University Department of Geography
  56. Center for Earth Observation, North Carolina State University
  57. Florida Atlantic University, Dept of Geography
  58. Michigan State University, Dept of Geography
  59. University of North Carolina at Greensboro
  60. Univerisy of Iowa Department of Geography
  61. School of Planning, Ahmedabad, India
  62. Houston Community College, Houston ,TX
  63. NIU Undergraduate Courses
  64. Stephen F. Austin State University
  65. Universitý di Venezia
  66. Bath Spa University College
  67. The Missouri Spatial Data Information Service
  68. Dept of Geography & Topographic Science, The University of Glasgow, UK
  69. Geography Internship Program, California State University, Long Beach
  70. Utah State University, RS/GIS Lab
  71. Kayin College
  72. Fachrichtung Geoinformatik und Vermessung der Fachhochschule Mainz
  73. Carleton University Dept of Geography-Ottawa, Canada
  74. Sam Houston State University
  75. GeoInfo Courses at Mohawk College
  76. University of Alabama, Geography Department
  77. British Columbia Institute of Technology
  78. Federal University of Parana-CIEG
  79. Northern Arizona University, Department of Geography and Public Planning
  80. University of Florida Geomatics Program
  81. Centre of Geographic Sciences (COGS), Canada
  82. Geodesy and Geomatics Engineering, University of New Brunswick, Canada
  83. McMaster University & Mohawk College GIS Specialist Certificate Program
  84. Algonquin College
  85. University of Winnipeg - Geography Department
  86. GeoPlan Center - University of Florida
  87. Wilfrid Laurier University
  88. Geographic Information Science Center at University of California, Berkeley
  89. St. Mary's University, Minnesota
  90. Metropolitan State College Denver
  91. Appalachian State University
  92. St. Cloud State University--Spatial Analysis Research Center
  93. UGA Center for Remote Sensing and Mapping Science
  94. Ryerson Polytechnic University, School of Applied Geography
  95. Appalachian State University Department of Geography and Planning
  96. University of Toledo
  97. University Of Technology Malaysia
  98. Northwest Missouri State University
  99. SUNY-ESF
  100. UniGIS at Simon Fraser University, Canada
  101. Pennsylvania State University
  102. ITC Home Page
  103. University of Waterloo, Environmental Studies
  104. Australian National University
  105. University of Arkansas CAST
  106. Edinburgh University
  107. Fuji University
  108. University of Karlsruhe
  109. University of Leeds
  110. University of Salzburg Institute for Geography
  111. Ohio State University Center for Mapping
  112. CalTech
  113. University of Wyoming
  114. Emporia State University
  115. Brigham Young University
  116. University of Nebraska
  117. Boston University
  118. University of California, Berkeley
  119. Oak Ridge National Laboratory
  120. University of Colorado
  121. University of Oklahoma
  122. University of Delaware
  123. Oregon State University
  124. George Mason University
  125. University of Pittsburgh
  126. University of Georgia
  127. Rutgers University
  128. Hunter College, City University of New York
  129. San Diego State University
  130. University of Idaho
  131. University of Southern California
  132. University of Massachusetts, Amherst
  133. Virginia Commonwealth University
  134. University of Washington
  135. Simon Fraser University
  136. Clark Labs/Clark University

GIS Employment Sources

GIS COMPANIES TO APPLY JOB

  1. ReMetrix
  2. Gaea Systems Pvt Ltd
  3. Eagan, McAllister Associates, Inc.
  4. ML Infomap
  5. Intermap Technologies
  6. geoVelocity
  7. RMSI
  8. AvisMap GIS Technologies
  9. GIS Innovations
  10. SigConsult
  11. GeoEmphasis.com
  12. Spatial Developers
  13. Avenza Systems, Inc.
  14. GISData
  15. Global Maps LTD
  16. Trek Construction & Environmental Services Ltd.
  17. PetersonGIS
  18. NAVTEQ
  19. ESRI Australia
  20. Spridata. Spatial IT Consultants
  21. IIC Technologies
  22. Tier 3, Inc.
  23. GeoMap Systems
  24. Yenom-Tech Software
  25. Intellias Software Development
  26. Sarana Primadata, Indonesia
  27. GISTech, Limited
  28. All West Surveys
  29. Mappamondo GIS
  30. Marquette GIS Consulting
  31. Assurgent Technology Solutions
  32. Munsys Technologies
  33. Open Spatial Inc.
  34. Midwest Infotech Pvt. Ltd
  35. Complete Spatial Solutions
  36. Tera Environmental Consultants
  37. Sound Geospatial Services, LLC
  38. Eric Beaton Urban Planning and GIS Services
  39. NMT Corporation
  40. Geo-3D, Inc.
  41. Cognocarta GIS, LLC
  42. OneMap, Ltd.
  43. MicroCenter, Bahrain
  44. Spatial Data Integrations
  45. International Business Integration
  46. Satyam Computer Services, Ltd.
  47. Satellite Imaging Corp
  48. MapWorld Technologies, Ltd.
  49. emGISt, India
  50. Upper 90 Systems, Inc.
  51. eSymmetry, Ecosystem Analysis and Programming
  52. Minecode, India
  53. GIS Landmark
  54. Rolta
  55. RMSI Global IT
  56. GEC, Inc.
  57. Weston & Sampson Engineers, Inc.
  58. Cinco Energy Land Services
  59. Gaea Systems Pvt Ltd
  60. CARIS
  61. Geodac Corporation
  62. Golder Associates Ltd.
  63. Miner & Miner
  64. Socket Technologies, Inc.
  65. Mada Geomatic, Madagascar
  66. DCSE, Inc.
  67. GeoCognition Consulting
  68. Geografx
  69. Peton Consulting
  70. Compusense
  71. GIS Consortium, India
  72. Nicol and Associates, Inc.
  73. Applied Data Consultants
  74. Chris Chubb Cartography
  75. Civil & Environmental Consultants, Inc.
  76. Keck & Wood, Inc.
  77. GEO-Sky Aerial Mapping & Surveying
  78. Michael Baker Corporation
  79. Ryan Galbraith
  80. NeST GIS
  81. Sai Infotech Systems, Ltd.
  82. Forte Consulting
  83. HNTB Corporation
  84. Critchlow Associates
  85. GIS Project, Ltd.
  86. GGP Systems
  87. GeoDecisions
  88. ENGECORC
  89. ETd
  90. Micro Documents Automation India Pvt. Ltd.
  91. Map Specifics
  92. Engineering Systems
  93. Farallon Geographics
  94. Spatial Data Analytics Corporation
  95. Landmark Geomatics
  96. Proficio Geo Technologies
  97. We Do IT
  98. Farm IT Solutions
  99. WTI Advanced Technology Limted, India
  100. TerraNOVA International, LLC
  101. AnalyGIS, LLC
  102. Galilee Enterprise
  103. Trans Global Geomatics
  104. Consumer Geomatics
  105. AABSyS IT
  106. Intec Infocom
  107. Compass Informatics
  108. CGIS-Consulting Geo Info Systems
  109. Infotech Enterprises, Ltd
  110. Sedgwick Associates
  111. Murphy's World GIS
  112. MapInfo Corporation
  113. Applied Geodetics
  114. Sutra Systems
  115. Spatial Data Private Limited
  116. Carmenta AB
  117. Red Paw Technologies, Inc.
  118. GIS Development.net
  119. Avineon, India
  120. GIS Mapping Solutions
  121. HCL Technologies
  122. Digital Globe
  123. ITSoft Solutions
  124. SETU Cybertech
  125. GISL - International GIS Consultants
  126. Research Solutions, Inc.
  127. Intelligent Decisions Systems, Inc.
  128. Infodesk Manipal Limited
  129. Environmental GIS Consulting, LLC
  130. Vanasse Hangen Brustlin, Inc. GIS Services
  131. Regency InfoTech
  132. ACRE Surveying and Development - Philippines
  133. Datacode
  134. Roads of India
  135. Astra Infosys - GIS Consulting
  136. Infodesk Manipal Limited
  137. Symmetry
  138. SUYOG GIS (P) Ltd.
  139. Nobel Software Systems
  140. Cuesta Systems, Inc.
  141. Millennium International Technologies, Inc.
  142. GEOAPIKONISIS Ltd, Greece
  143. geOme Tec
  144. Magnasoft Spatial Services
  145. Tobin International, LTD
  146. Buana Katulistiwa-NGO for Spatial Information in Indonesia
  147. ICONSNET International Consultants Network
  148. Sathya Technology
  149. Newcyber3D
  150. INFORM--Network for Management Systems Ltd.
  151. Bentley GIS Solutions
  152. Fi-Sofex Ltd., Bangalore
  153. Relief - GIS Consulting and Software
  154. Intermap (PTY) Ltd
  155. Surya Soft-Tech Ltd., Bangalore, India
  156. DataPro Consulting
  157. Integrated Mapping Services, Inc.
  158. Manchitra Services Pvt Ltd
  159. Navgati Geomatics
  160. Talon Associates
  161. InfoTech Enterprises, Inc.
  162. GeoPlus
  163. GisGroup - Il portale italiano del GIS
  164. Sar Softech
  165. GeoDigital Mapping
  166. Khatib & Alami Consolidated Engineering Company
  167. geoVue
  168. InfoTech Enterprises Ltd
  169. Atresh GIS-CAD Consultants
  170. Arraycom India
  171. Realworld 00 Systems Osterreich
  172. C.L.M. Consulting - Network Planning GIS Security
  173. Intelligent IT/GIS Solutions
  174. Applied Geography Consulting Group, Inc.
  175. geo-konzept
  176. ICL Integrated Mapping System
  177. Etak
  178. TeleAtlas
  179. GEOvision, Denmark
  180. MapMedia, Germany
  181. Mayes, Sudderth and Etheredge
  182. EOSGIS GIS services and 3D Terrain Visualization
  183. Star Informatic
  184. INDUS Corporation
  185. Waypoint Technology Group
  186. AverStar Geospatial Services
  187. The Titan Corporation
  188. Pixxures, Inc.
  189. New Century Software
  190. Techni Graphic Systems, Inc.
  191. Safe Software, Inc.
  192. James W. Sewall Company
  193. PCI Geomatics
  194. IIC Technologies
  195. ESRI India
  196. Geographic Technologies Group, Inc.
  197. Atlantic Technologies
  198. GIS Solutions
  199. Camp Dresser & McKee Inc. Information Management and GIS
  200. The MapShop
  201. The National Imagery and Mapping Agency
  202. Schaub GIS Consulting
  203. 3CRC Technologies
  204. GIS Associates
  205. Comsearch Online
  206. James Davey and Associates, Inc.
  207. Apex Data Services, Inc.
  208. Kirpalaney & Associates (Engineers) Pvt. Ltd
  209. Map Gallery
  210. ESRI
  211. Scout Geographics
  212. Osmose, Inc.
  213. M. A. Young & Associates, Inc.
  214. Earthward Consulting, Inc.
  215. Manifold
  216. Perly's Maps - Canada
  217. GIS/Trans, Ltd.
  218. InfoTech Enterprises Ltd.
  219. C-Plan
  220. Analytical Surveys, Inc.
  221. Enghouse Systems Limited
  222. PlanGraphics, Inc.
  223. CLIRSEN
  224. SDS, Inc.
  225. GDSI Hawaii - Home
  226. GIS Project Development
  227. Foresta SG
  228. Smallworld GIS
  229. CSA Arquitects & Engineers
  230. WESTON Knowledge Solutions & Systems
  231. Barclay Maps, California
  232. SEMCOR GIS services
  233. Pacific Meridian Resources
  234. Dewberry & Davis
  235. Woolpert LLP
  236. Clarkson Map Company
  237. Geographic Resource Solutions
  238. ESRI
  239. Planet One
  240. M.J. Harden Associates, Inc.
  241. MARIS
  242. James W. Sewall Co.
  243. Cuesta Systems, Inc.
  244. SIGNAL Corporation
  245. Riverside Technology, Inc.
  246. ERDAS
  247. VectorVision Corporation
  248. PCI
  249. Oracle Corporation
  250. SmallWorld
  251. Leica
  252. CERL
  253. RADARSAT
  254. Information Solutions, Inc.
  255. Idrisi
  256. GeoGraph International Corporation
  257. Scan/US, Inc.
  258. Caliper
  259. EROS
  260. GeoResearch
  261. ASI Landmark, Inc.
  262. Leica Geosystems Inc.
  263. AR Software Services
  264. InfoGlobe, Inc.
  265. Integrated Spatial Solutions, Inc.
  266. GeoData Solutions, Inc.
  267. H.L. Yoh Company LLC
  268. SPOT Image Corporation
  269. Cargill, Inc.
  270. Argonne National Laboratory
  271. Spatial Insights, Inc.
MORE TO COME..,

GIS LINKS

Some of the wonderful GIS sites to explore for the deep techie contents

What is GIS?

GIS is a computer system for capturing, storing, checking, integrating, manipulating, analysing and displaying data related to positions on the Earth's surface. Typically, a Geographical Information System is used for handling maps of one kind or another. These might be represented as several different layers where each layer holds data about a particular kind of feature. Each feature is linked to a position on the graphical image on a map and a record in an attribute table. GIS can relate otherwise disparate on the basis of common geography, revealing hidden patterns, relationships, and trends that are not readily apparent in spreadsheets or statistical packages, often creating new information from existing data resources.

Hidden in most data is a geographical component: an address, postal code, census block, city, county, or latitude/longitude coordinate. With GIS, you can explore the spatial element of your data to display soil types, track crime patterns, analyze animal migration patterns, find the best location for an expanding business, model the path of atmospheric pollution, and make decisions for many types of complicated problems.

These presentations (pdf files) includes both introductory GIS material and an overview of its application to research in a particular discipline.

Courtesy:http://www-sul.stanford.edu/depts/gis/whatgis.html
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SITE CONTAINS LATEST GIS, REMOTE SENSING TUTORIAL. GIS CAREER, GIS JOBS.NOTES RESOURCES. RankingBlogs.com :: Defining Your Blogs Worth: TopSites: Technorati Profile Add to Technorati Favorites REMOTE SENSING & GEO INFORMATICS

GIS COMPANIES LINKS

  1. ReMetrix
  2. Gaea Systems Pvt Ltd
  3. Eagan, McAllister Associates, Inc.
  4. ML Infomap
  5. Intermap Technologies
  6. geoVelocity
  7. RMSI
  8. AvisMap GIS Technologies
  9. GIS Innovations
  10. SigConsult
  11. GeoEmphasis.com
  12. Spatial Developers
  13. Avenza Systems, Inc.
  14. GISData
  15. Global Maps LTD
  16. Trek Construction & Environmental Services Ltd.
  17. PetersonGIS
  18. NAVTEQ
  19. ESRI Australia
  20. Spridata. Spatial IT Consultants
  21. IIC Technologies
  22. Tier 3, Inc.
  23. GeoMap Systems
  24. Yenom-Tech Software
  25. Intellias Software Development
  26. Sarana Primadata, Indonesia
  27. GISTech, Limited
  28. All West Surveys
  29. Mappamondo GIS
  30. Marquette GIS Consulting
  31. Assurgent Technology Solutions
  32. Munsys Technologies
  33. Open Spatial Inc.
  34. Midwest Infotech Pvt. Ltd
  35. Complete Spatial Solutions
  36. Tera Environmental Consultants
  37. Sound Geospatial Services, LLC
  38. Eric Beaton Urban Planning and GIS Services
  39. NMT Corporation
  40. Geo-3D, Inc.
  41. Cognocarta GIS, LLC
  42. OneMap, Ltd.
  43. MicroCenter, Bahrain
  44. Spatial Data Integrations
  45. International Business Integration
  46. Satyam Computer Services, Ltd.
  47. Satellite Imaging Corp
  48. MapWorld Technologies, Ltd.
  49. emGISt, India
  50. Upper 90 Systems, Inc.
  51. eSymmetry, Ecosystem Analysis and Programming
  52. Minecode, India
  53. GIS Landmark
  54. Rolta
  55. RMSI Global IT
  56. GEC, Inc.
  57. Weston & Sampson Engineers, Inc.
  58. Cinco Energy Land Services
  59. Gaea Systems Pvt Ltd
  60. CARIS
  61. Geodac Corporation
  62. Golder Associates Ltd.
  63. Miner & Miner
  64. Socket Technologies, Inc.
  65. Mada Geomatic, Madagascar
  66. DCSE, Inc.
  67. GeoCognition Consulting
  68. Geografx
  69. Peton Consulting
  70. Compusense
  71. GIS Consortium, India
  72. Nicol and Associates, Inc.
  73. Applied Data Consultants
  74. Chris Chubb Cartography
  75. Civil & Environmental Consultants, Inc.
  76. Keck & Wood, Inc.
  77. GEO-Sky Aerial Mapping & Surveying
  78. Michael Baker Corporation
  79. Ryan Galbraith
  80. NeST GIS
  81. Sai Infotech Systems, Ltd.
  82. Forte Consulting
  83. HNTB Corporation
  84. Critchlow Associates
  85. GIS Project, Ltd.
  86. GGP Systems
  87. GeoDecisions
  88. ENGECORC
  89. ETd
  90. Micro Documents Automation India Pvt. Ltd.
  91. Map Specifics
  92. Engineering Systems
  93. Farallon Geographics
  94. Spatial Data Analytics Corporation
  95. Landmark Geomatics
  96. Proficio Geo Technologies
  97. We Do IT
  98. Farm IT Solutions
  99. WTI Advanced Technology Limted, India
  100. TerraNOVA International, LLC
  101. AnalyGIS, LLC
  102. Galilee Enterprise
  103. Trans Global Geomatics
  104. Consumer Geomatics
  105. AABSyS IT
  106. Intec Infocom
  107. Compass Informatics
  108. CGIS-Consulting Geo Info Systems
  109. Infotech Enterprises, Ltd
  110. Sedgwick Associates
  111. Murphy's World GIS
  112. MapInfo Corporation
  113. Applied Geodetics
  114. Sutra Systems
  115. Spatial Data Private Limited
  116. Carmenta AB
  117. Red Paw Technologies, Inc.
  118. GIS Development.net
  119. Avineon, India
  120. GIS Mapping Solutions
  121. HCL Technologies
  122. Digital Globe
  123. ITSoft Solutions
  124. SETU Cybertech
  125. GISL - International GIS Consultants
  126. Research Solutions, Inc.
  127. Intelligent Decisions Systems, Inc.
  128. Infodesk Manipal Limited
  129. Environmental GIS Consulting, LLC
  130. Vanasse Hangen Brustlin, Inc. GIS Services
  131. Regency InfoTech
  132. ACRE Surveying and Development - Philippines
  133. Datacode
  134. Roads of India
  135. Astra Infosys - GIS Consulting
  136. Infodesk Manipal Limited
  137. Symmetry
  138. SUYOG GIS (P) Ltd.
  139. Nobel Software Systems
  140. Cuesta Systems, Inc.
  141. Millennium International Technologies, Inc.
  142. GEOAPIKONISIS Ltd, Greece
  143. geOme Tec
  144. Magnasoft Spatial Services
  145. Tobin International, LTD
  146. Buana Katulistiwa-NGO for Spatial Information in Indonesia
  147. ICONSNET International Consultants Network
  148. Sathya Technology
  149. Newcyber3D
  150. INFORM--Network for Management Systems Ltd.
  151. Bentley GIS Solutions
  152. Fi-Sofex Ltd., Bangalore
  153. Relief - GIS Consulting and Software
  154. Intermap (PTY) Ltd
  155. Surya Soft-Tech Ltd., Bangalore, India
  156. DataPro Consulting
  157. Integrated Mapping Services, Inc.
  158. Manchitra Services Pvt Ltd
  159. Navgati Geomatics
  160. Talon Associates
  161. InfoTech Enterprises, Inc.
  162. GeoPlus
  163. GisGroup - Il portale italiano del GIS
  164. Sar Softech
  165. GeoDigital Mapping
  166. Khatib & Alami Consolidated Engineering Company
  167. geoVue
  168. InfoTech Enterprises Ltd
  169. Atresh GIS-CAD Consultants
  170. Arraycom India
  171. Realworld 00 Systems Osterreich
  172. C.L.M. Consulting - Network Planning GIS Security
  173. Intelligent IT/GIS Solutions
  174. Applied Geography Consulting Group, Inc.
  175. geo-konzept
  176. ICL Integrated Mapping System
  177. Etak
  178. TeleAtlas
  179. GEOvision, Denmark
  180. MapMedia, Germany
  181. Mayes, Sudderth and Etheredge
  182. EOSGIS GIS services and 3D Terrain Visualization
  183. Star Informatic
  184. INDUS Corporation
  185. Waypoint Technology Group
  186. AverStar Geospatial Services
  187. The Titan Corporation
  188. Pixxures, Inc.
  189. New Century Software
  190. Techni Graphic Systems, Inc.
  191. Safe Software, Inc.
  192. James W. Sewall Company
  193. PCI Geomatics
  194. IIC Technologies
  195. ESRI India
  196. Geographic Technologies Group, Inc.
  197. Atlantic Technologies
  198. GIS Solutions
  199. Camp Dresser & McKee Inc. Information Management and GIS
  200. The MapShop
  201. The National Imagery and Mapping Agency
  202. Schaub GIS Consulting
  203. 3CRC Technologies
  204. GIS Associates
  205. Comsearch Online
  206. James Davey and Associates, Inc.
  207. Apex Data Services, Inc.
  208. Kirpalaney & Associates (Engineers) Pvt. Ltd
  209. Map Gallery
  210. ESRI
  211. Scout Geographics
  212. Osmose, Inc.
  213. M. A. Young & Associates, Inc.
  214. Earthward Consulting, Inc.
  215. Manifold
  216. Perly's Maps - Canada
  217. GIS/Trans, Ltd.
  218. InfoTech Enterprises Ltd.
  219. C-Plan
  220. Analytical Surveys, Inc.
  221. Enghouse Systems Limited
  222. PlanGraphics, Inc.
  223. CLIRSEN
  224. SDS, Inc.
  225. GDSI Hawaii - Home
  226. GIS Project Development
  227. Foresta SG
  228. Smallworld GIS
  229. CSA Arquitects & Engineers
  230. WESTON Knowledge Solutions & Systems
  231. Barclay Maps, California
  232. SEMCOR GIS services
  233. Pacific Meridian Resources
  234. Dewberry & Davis
  235. Woolpert LLP
  236. Clarkson Map Company
  237. Geographic Resource Solutions
  238. ESRI
  239. Planet One
  240. M.J. Harden Associates, Inc.
  241. MARIS
  242. James W. Sewall Co.
  243. Cuesta Systems, Inc.
  244. SIGNAL Corporation
  245. Riverside Technology, Inc.
  246. ERDAS
  247. VectorVision Corporation
  248. PCI
  249. Oracle Corporation
  250. SmallWorld
  251. Leica
  252. CERL
  253. RADARSAT
  254. Information Solutions, Inc.
  255. Idrisi
  256. GeoGraph International Corporation
  257. Scan/US, Inc.
  258. Caliper
  259. EROS
  260. GeoResearch
  261. ASI Landmark, Inc.
  262. Leica Geosystems Inc.
  263. AR Software Services
  264. InfoGlobe, Inc.
  265. Integrated Spatial Solutions, Inc.
  266. GeoData Solutions, Inc.
  267. H.L. Yoh Company LLC
  268. SPOT Image Corporation
  269. Cargill, Inc.
  270. Argonne National Laboratory
  271. Spatial Insights, Inc.

MORE TO COME..,