Amsa-Ortho mathematically rectifies and reconstructs scanned photography so that the distortions created by terrain relief and camera orientation are removed. Generated from standard aerial photographs in digital form, the Amsa-Ortho can be directly overlaid on base maps, without any apparent junction and without any

distortion due to the relief. Updated and precise images of whole areas can now be stored on the hard drive of one single PC. Amsa-Ortho offers the methodology to economically produce mosaics of digital aerial photographs. The Amsa-Ortho system solves the adjustment problem of adjoining photographs when producing geo-referenced aerial image mosaics. Amsa-Ortho can use almost any existing terrain elevation model or even existing 3D Amsa, dwg and dgn topography files, or use terrain elevation model produced from Amsa Digital Compiler. The system consists of an interactive model and a batch module. The interactive module allows the user to control quality during the formation of mosaics, thus ensuring a perfect final result after the images have been resampled. The ortho images, in tif format, can be geo-referenced with the tfw files in Amsa98/NT , AutoCad and MicroStation.

The Digital Orthophoto is created by scanning an aerial photograph diapositive transparency with an image scanner. Since the accuracy of the digital image is directly related to the scan resolution, a higher precision image scanner produces more accurate images. Using the Amsa Digital Orthophoto module, the scanned data file is then digitally rectified to an orthographic projection by processing each image pixel. This process requires, as input, ground control points, camera orientation parameters, and a Digital Elevation Model (DEM) and high resolution image file. The digital orthophoto can be used as a map for measuring distances, positions, and areas or used in overlaying & linking raster and existing vector data.

A classic use for Amsa-Ortho can be found in Urban Planning, where considerable savings can be generated by updating land information using Amsa Ortho photos. The user has instant access to the whole or any part of a territory, with great accuracy. With Amsa Ortho, image brightness and contrast can be enhanced, and the image can be plotted in hardcopy form using desktop publishing software or by a professional print shop.

System Configuration

Software Requirements