Photogrammetric mapping services for government and commercial GIS users. Knowledge of advanced photogrammetric environments and geospatial applications enables us to provide support at all stages of the digital Photogrammetric process.
Digital Aero Triangulation
Aerial Triangulation (AT) is the process of densifying and extending ground control through computational means. AT extends horizontal and vertical control from relatively few ground survey control points to each unknown ground point included in the solution. The supplemental control points are called tie points, and they are used to control subsequent photogrammetric mapping. Each stereo model is scaled and leveled using the adjusted coordinate values of the pass points located in the stereo model.
In simple language the collective orientation of more than two photos is called Aerial Triangulation.
3D Feature Extraction
Planimetric mapping shows only horizontal features on a plane surface, without elevation contours to depict the terrain, whereas in topographic mapping contour and elevations are vital parts.
In other words Planimetric/Topographic Mapping is a representation of the Earth surface features in 3D manner and used for geospatial analysis and modeling. The preparation of map is done by extracting vector or point information of railroads, buildings, hydrological features, vegetation, etc., as required by the user by different Symbols (trees, wells, poles, etc.,), Line types (rail, road, streams, etc.,) and Regions (buildings, tanks, forest, etc.,) with IDs.
Digital Terrain Modeling (DTM)
Digital Terrain Modeling (DTM) is the collection of mass points of elevations and 3D break lines at each change of terrain using softcopy workstations.
We can survey breaklines and masspoints at the top and bottom of every rut, dip, cut, ditch, curb, culvert, spillway, headwall, bulkhead, shoreline, pile, grade, ramp, bridge etc.
The mass points are collected at a grid spacing that meets project requirements. A Digital Terrain Model represents the terrain accurately enough to generate contours that meet accuracy Standards.
Digital Ortho Photography
Digital Ortho photography provides an enhanced on-screen view of features not captured during traditional mapping operations.
Digital Ortho photography process rectifies aerial photographs to remove distortions caused by:
Digital Orthophoto is a raster image generated by differentially rectifying scanned aerial photographs to compensate for distortions due to the altitude of the aircraft and the relief of the terrain. Digital Ortho photos combine the image characteristics of a photograph with geometric qualities of a map
Digital orthophotograhy has become an accepted base map for geographic information systems for a wide variety of uses, including:
Utility GIS:
Utility Sector is one of the fastest growing sector in which Geographical Information System (GIS) is used. GIS is emerging as an important planning, implementation and operation management tool for the utility industries such as Telecom, Transportation, Energy and several Urban utilities such as Water Supply, Waste Water, Power supply and Health.
In a GIS, the actual physical structure of the distribution system - where the lines run, where the connections are - can be duplicated or modeled on the computer along with streets, buildings, and land ownership boundaries, that have a bearing on the distribution system.