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