Thursday, August 19, 2010

Study on WetLands

SBL Undertakes A Temporal Study On Wetlands
SBL has ventured into a new temporal study, this time, in the coastal region of Kerala. Satellite imageries are being analyzed over the last four decades to find the decadal variations in the land use of Kole lands of Malappuram and Trissur Districts in the state of Kerala, India.

For details click here

Wednesday, July 21, 2010

Article - Mapping Services

The integration, storage, editing, analysis, sharing, and displaying of geographical information by merging cartography and database technology is known as GIS Mapping.

To know more about GIS Mapping services check this article GIS Mapping Services

Thursday, July 1, 2010

DEM/DTM Generation

Digital Elevation Model is the representation of earth’s topography using digital methods. Digital elevation model is also called as digital terrain model (DTM). DEMs or DTMs can be represented as original maps, square grids or irregular network of triangles.
The main application of DEM are,
To get more information check this link DEM/DTM generation

Check this video

Monday, March 29, 2010

Georeferenced data processing services

To georeference something means to define its existence in physical space,which means establishing its location in terms of map projections or coordinate systems. The term is used both when establishing the relation between raster or vector images and coordinates but also when determining the spatial location of other geographical features. Examples would include establishing the correct position of an aerial photograph within a map or finding the geographical coordinates of a place name or street address. This procedure is thus imperative to data modeling in the field of geographic information systems (GIS) and other cartographic methods.These can be done by georeferenced data processing service providers. When data from different sources need to be combined and then used in a GIS application, it becomes essential to have a common referencing system. This is brought about by using various georeferencing techniques. Most georeferencing tasks are undertaken either because the user wants to produce a new map or because they want to link two or more different datasets together by virtue of the fact that they relate to the same geographic locations.

reference: wikipedia

Photogrammetry services

Digital photogrammetry includes

* Tile generation in user defined dimension
* Contour generation
* stereo compilation
* Lidar data processing
* orthophotography services
* Mosaicking and tile generation
* Pan sharpening
* Change detection
* 3D terrain visualization
* Slope aspect analysis
* Land cover classification
* Aerial Triangulation services
* Satellite Imagery Interpretation and Classification
* Topographic / planimetric / 3D feature extraction
* Digital elevation modeling and editing (DEM,DTM)
* Orthophoto generation | Orthorectification
* Color Balancing, Creating mosaics
* Edge matching
* Triangulated irregular network (TIN)

Thursday, March 18, 2010

Importance of CAD drafting

CAD drafting services plays an important role in our daily life.CAD is an important industrial art extensively used in all areas and in many applications, including automotive, shipbuilding,aerospace industries, industrial and architectural design, prosthetics, and many more. CAD has been a major driving force for research in computational geometry, computer graphics (both hardware and software), and discrete differential geometry.

Because of its enormous economic importance, CAD drawings are the most effective way to document technical drawings and related information in an organized manner. CAD combined with GIS enables data to be analysed geographically.

CAD conversion services ranges from GIS to CAD format conversion,
CAD to GIS format conversion, CAD Drafting, paper to CAD conversions etc.

Wednesday, March 10, 2010

GIS mapping services

Mapping services are categorized based on user specified specifications.
some of the important services are:
* Custom mapping: Mapping Services and GIS Data for Businesses purposes
* Shoreline mapping: The wet/dry line is the feature mapped as the shoreline on historical photography. Therefore to detemine a representative elevation of the wet/dry line so that our lidar-derived elevation-based shoreline is comparable to earlier mapped shorelines.
* Utility mapping : This mapping experience ranges from in all sort of field ie small corner gas stations, through industrial plants, military installations, to entire towns, and involves every type and construction of pipe and cable - including utilities beneath buildings or other structures.
* Muncipal mapping : Includes mapping of town planning.
* Parcel mapping
* Mapping of reclamation activities
* Wildlife and habitat monitoring

Tuesday, February 16, 2010

Creation ofDigital Elevation Model (DEM)

For the accurate removal of the image distortions, a digital elevation model (DEM) is used to make image orthorectification. The requisite DEM can be produced by semi-automatic DEM extraction software from stereo satellite scenes obtained by the QuickBird, IKONOS, SPOT-5, or ASTER satellite sensors, and stereo aerial photography.

In situations where higher mapping accuracy standards are required, the DEM is extracted from the already existing topographic maps with reference to a standard scale or collected using stereo satellite image data.

To obtain this accuracy standard, adequate GPS-derived ground control points (GCPs) are necessary. Other remote sensing techniques can also be used such as radar interferometry or LIDAR.

When a particular vector data needs to be extracted from satellite or aerial image data by raster-to-vector translation, the process of ortho rectification of the remotely sensed image data can rectify all digital images of geological, environmental, topographic or any other source map which will be used in the GIS mapping environment.

Creating anOrthophoto / Orthorectification

In the areas of GIS data acquisition, visualization and general mapping, digital satellite imagery and aerial photographs have a significant place.Photographs obviously provide a solid visual effect. Imperceptible spatial concepts are more clearly understood by viewing the photographs. These are not photographs taken by ordinary cameras. These are very professional high-end cameras with higher zoom and clarity.
Another important role of these photos is to provide a foundation for collecting the spatial information needed. Data in the form of the satellite images or aerial photographs must be taken without any distortions, if you need to gather information useful for a mapping or GIS system in the case of roads, marine forms or vegetation.
This process of correcting the distortions of a satellite image of aerial photograph is called Orthophoto rectification.This process allows you to make direct and precise measurements of areas, distances, angles, positions etc.

Wednesday, February 3, 2010

Web mapping services

The GIS /Mapping services specializes in Graphical Information Systems (GIS), and has produced several interactive online maps (and printed maps) for public use.Today, a variety of Web mapping services exist, each of them providing a similar interface to extensive mapping and other GIS data.Compare various web map services and service providers
, .

Tuesday, February 2, 2010

What is orthophoto generation and orthophotography?

An Orthophoto or orthophotograph is an aerial photograph geometrically corrected ("also known as ortho rectified , can be done by service providers ie Orthophoto rectification service"). Unlike an uncorrected aerial photograph, an orthophotograph can be used to measure true distances, because it is an accurate representation of the earth's surface, having been adjusted for topographic relief lens distortion, and camera tilt.The concept of geo-rectification services/georectification services comes under Orthophoto rectification service.
Orthophotographs are commonly used in the creation of a(GIS) Geographic Information System and is useful in GIS mapping services. Software can display the orthophoto and allow an operator to digitize or place linework, text annotations or geographic symbols (such as hospitals, schools, and fire stations). Some software can process the orthophoto and produce the linework automatically.

An orthophoto is an aerial photograph planimetrically corrected, thus an orthophoto is generated Orthophotographs have the positive attributes of a photograph such as detail and timely coverage, and the positive attributes of a map including uniform scale and true geometry. This enables orthophotographs to be used in their primary role as a backdrop on which map features can be overlaid. Orthophotos represent the primary use of remote sensing

Orthophotos are now created by scanning aerial photographs and converting them into a raster image file format. A digital terrain model is added as a means of collecting ground points to indicate the changes in elevation. When control points are identified on the aerial photos, stereo models are developed and geometric distortions are estimated. The image is rectified and georeferened using mathematical models of photogrammetry to remove tilt, terrain, atmospheric and other digital image distortions.
Multiple photographs can be analyzed, corrected, and mosaicked / mosaicing all at once by a process called “bundle adjustment”, in which interrelated sets of equations are used to find a globally optimal set of corrections across all photographs. If a photo is black and white, each pixel is assigned a single numerical value corresponding to its light intensity. Color orthophotos are handled in an analogous way by transforming a vector of light intensities for different color bands into a single number. After the model has been scanned, the film is then developed as a negative orthophotograph, and it would usually be brought to the required scale by appropriate scaling or setting of the stereomodel and can be enlarged or reduced by the user if the scaling has not been adjusted after being scanned.

Reference : Wikipedia

Friday, January 29, 2010

Common uses of DEMs

Extracting terrain parameters,Modeling water flow or mass movement (for example avalanches and landslides),Creation of relief maps,Rendering of 3D visualizations,3d flight planning,Creation of physical models (including raised-relief maps),Rectification of aerial photography or satellite imagery, Reduction (terrain correction) of gravity measurements (gravimetry, physical geodesy), Terrain analyses in geomorphology and physical geography, geographic information system(GIS), Engineering and infrastructure design, Global positioning systems (GPS), Line-of-sight analysis, Base mapping, Flight simulation, Precision farming and forestry, surface analysis, Intelligent transportation systems (ITS).

Reference: Wikipedia

Thursday, January 28, 2010

Remote sensing and photogrammetry Applications

Does anyone knows the inventor of LiDAR ?
LiDAR discovered by hendy in 1976.Light detection and ranging (LIDAR) is well known in the examples of weapon ranging, laser illuminated homing of projectiles.Lidar services is used to detect and measure the concentration of various chemicals in the atmosphere, while airborne LIDAR can be used to measure heights of objects and features on the ground more accurately than with radar technology. Vegetation remote sensing is a principle application of LIDAR.

Wednesday, January 20, 2010

What is aerial triangulation and aerial photogrammetry?

Aerial photogrammetry is a technique for creating two dimensional 2D or 3D models from aerial photographs, which are pictures of the Earth from a high point, usually an airplane. Aerial photogrammetry usually requires photographs of two or more angles of the same area in order to map the image, and it may or may not involve computer software. These photographs are then turned into the models by cartographers.
The Aerial photogrammetry services is used to create topographical maps. These maps may be either 2D or, more recently, 3D computer models of terrain. The resulting maps and models may be useful in analyzing both small and large geographical areas. These maps may be used as a basis for, or in conjunction with, GIS data.Also Aerial Triangulation is the calculation of true ground co-ordinates, used as the base reference in photogrammetry.

Thursday, January 14, 2010

Digital Elevation/ Digital Terrain Model Tips (DEM/DTM)

Digital elevation are frequently obtained by remote sensing rather than direct survey. These can be prepared in a number of ways,but one of the powerful technique for generating digital elevation model is interferometric synthetic aperture radar: two passes of a radar satellite (such as RADARSAT-1), or a single pass if the satellite is equipped with two antennas (like the SRTM instrumentation), suffice to generate a digital elevation map tens of kilometers on a side with a resolution of around ten meters.
A digital elevation model (DEM) or digital elevation modeling is a digital representation of ground surface topography or terrain, thus also widely known as a digital terrain model (DTM) or digital terrain modeling. A DEM can be represented as a raster , a grid of squares or as a triangular irregular network. digital elevation models are commonly built using remote sensing techniques, but they may also be built from land surveying. DEMs are used often in GIS, and are the most common basis for digitally-produced relief maps. DTM DEM generation is commonly used in remote sensing gis.

GIS Application development and software development

In GIS Application development and software development first of all we create spatial information systems to accelerate client businesses forward and offers Map Customization, GIS Application customization, Custom Tool Development, Application Migration, Web GIS, mobile mapping applications
etc . Now GIS mapping companies are there for GIS software development, GIS web Applications development.

Geographic information systems (GIS) (also known as Geospatial information systems) are computer software and hardware systems that enable users to capture, store, analyse and manage spatialially referenced data etc.

Monday, January 11, 2010

How GIS and CAD Interrelated ?

Computer aided design (CAD) is the use of computer technology for the design of objects, real or virtual. CAD often involves more than just shapes. GIS and CAD are interrelated, an eg is Carrying GIS Data in AutoCAD .As in the manual drafting of technical and engineering drawings, the output of CAD often must convey also symbolic information such as materials, processes, dimensions, and tolerances, according to application-specific conventions.CAD is extensively used in many applications such as automotive, shipbuilding, and aerospace industries, industrial and architectural design, prosthetics, and many more. Now CAD is also widely used to produce computer animation for special effects in movies, advertising and technical manuals.CAD also very helpful for research in computational geometry, computer graphics (both hardware and software), and discrete differential geometry.
Some of the GIS services and CAD conversions offered in CAD are as follows:

• Autocad drafting
• Engineering /Mechanical services
• Scan to cad conversion
• AutoCAD coversion to drawings
• Confidential cad conversion
• DGN conversion
• Multilayer Cad conversion
• AutoCAD digitization
• GIS to CAD
• Paper to CAD

Thursday, January 7, 2010

Latest GIS technology Concepts

We all knows about GIS , ie Geographic information system. Simply we can describe as Geographical Information System is any system that captures, stores, analyzes, manages, and presents data that is linked to location. When we consider GIS technically we can explain as, it is a system that includes mapping software and its application to photogrammetry, remote sensing, land surveying, aerial photography and photogrammetry, mathematics,mapping, geography, and tools that can be implemented with GIS software. Still, many refer to "Geographic Information System" as "GIS" even though it doesn't cover all tools connected to topology.We can also consider GIS as the merging of cartography and database technology.

Let us check various trends and applications in GIS Technology

• GIS and Science—3D analysis, graphing and data exploration, and more
Customization and Application Development- It includes Design and Development
• Creation / Maintenance of Geo spatial Database - Design, Development and maintenance of custom geospatial databases
• Data Integration and Data Format Conversion - Also includes Spatial Analysis and Modeling
Map Digitization / Vectorization - Digitizing maps
Feature Extraction - 2D, 3D feature extraction using AT( aerial triangulation) results
Ortho photography - Orthophoto Rectification and Mosaicing
Network Analysis - Design spatial database and model features on a 3D surface for network analysis used by organizations/agencies.
Web Mapping / Web GIS - Geodatabase Designing & Modeling, Web Mapping Automation
Geo-Coding - Important point with mapping is registering a map with the correct real world coordinates,ie Image Georectification / Georeferencing
• GIS and CAD — Building information modeling (BIM), 3D GIS, and more
Enterprise GIS—Extending geospatial capabilities to the enterprise
• Server GIS—Delivering geospatial services through a wide variety of clients
Mobile GIS—Making the mobile workforce more efficient
• Cartography—Additional cartographic mapping, analysis, and editing tools
Lidar data processing - Mapping and laser scanning

There are various many other applications in GIS technology, which can be discussed in more detail later in next article.For more details and for any queries contact