Automatic extraction of vertical obstruction information from interferometric SAR elevation data

Vertical obstructions (VOs) such as radio towers, power pylons, and windmills present a hazard to low-flying aircraft. We describe an automated VO detection scheme that processes digital surface models (DSMs) provided by interferometric SAR (InSAR) systems to produce heights and locations of VOs. By using only the height data from the InSAR, the resulting techniques can be applied to other DSM sources, such as lidar. Innovative morphological filtering algorithms are described, which optimize detection performance against various DSM resolutions over smooth or rough terrain. The height and position estimates of the detected VOs are computed, and they compare favorably to ground truth. Software that implements these algorithms has been packaged as an add-on module to ERDAS IMAGINE®.