Photogrammetry is the art, science, and technology of obtaining reliable information about physical objects and the environment through the process of recording, measuring, and interpreting photographic images and patterns of electromagnetic radiant energy and other phenomena.
With the introduction of computer-based, softcopy photogrammetric mapping and GIS systems that operate in a desktop computing environment prove to be a more economical solution for many mapping and GIS database construction tasks. It also presents visual reference of the earth's surface, providing a clear image base for design engineering, asset management, planning, and change detection, among others.
Utilizing photogrammetric processes, we can extract vector data such as contours, street centerlines, hydrography, utilities, vegetation, building footprints, etc. This data can be populated with attribute information pertaining to each feature, thus creating an intelligent database related to a particular geographic area.
Digital Elevation Models:
A DEM (Digital Elevation Model) is a collection of discrete elevation points at regularly spaced intervals, while a DTM (Digital Terrain Model) defines topographic shapes by elevation points at significant topographic features which reflect abrupt changes in relief such as incised streams, ridge lines, and slope breaks.
In either case, these data points provide a regular (DEM) or irregular (DTM) pattern of elevation information that can be used for many purposes, such as the generation of a triangular irregular network (TIN), where groupings of three elevation points create adjoining triangular surfaces which mathematically approximate the ground surface.
Orthorectification:
An orthophoto map is produced by removing scale variations from the original aerial photography. The original aerial photograph is not a true map because as the elevation of the ground changes, the scale of the image also changes. By using an accurate representation of ground elevations, we are able to fully rectify the ortho image so that all features are correctly located.
We do orthorectification of aerial photographs & spatial imagery to produce map-quality ortho images. In preparation for orthorectification of air photos or satellite imagery, we obtain the source material to extract digital elevation models. Mass points, break lines, and contour interpolation features (CIP) are collected and processed in specialized software to generate digital terrain models. Cross sections of corridors are generated from 3D data for the design of highways, pipelines, and power line rights-of-way.
Products:
Topographical & Thematic Maps
Orthorectified Photographs
Aerial Triangulation & Adjustment
Stereo Compilation
Terrain Modeling; DTM Generation
DTM Based Route Alignment
Feature Extraction & Validation
Automated Change Detection in Land use & Land Cover
Creation of Digital Elevation Models
Creating, Balancing & Mosaic king of Orthophotos
Editing of Ground Features & Elevation Data
Flythrough Models
Our Remote Sensing & Digital Photogrammetry Practice is powered with full feature PCI, Intergraph, ERDAS & ER Mapper workstations with dual monitors.
