Automatic Detection and Positioning of Ground Control Points Using TerraSAR-X Multi-Aspect Acquisitions

TL;DR

This paper presents three automatic strategies for detecting identical ground targets in multi-aspect TerraSAR-X SAR images to generate accurate ground control points for 3D localization in urban areas.

Contribution

It introduces novel automatic detection methods and a complete workflow for generating large numbers of GCPs from SAR data, demonstrated on TerraSAR-X images.

Findings

Successful automatic detection of common scatterers in urban SAR images

Generation of high-precision GCPs using the proposed workflow

Applicability demonstrated on datasets from Oulu and Berlin

Abstract

Geodetic stereo Synthetic Aperture Radar (SAR) is capable of absolute three-dimensional localization of natural Persistent Scatterer (PS)s which allows for Ground Control Point (GCP) generation using only SAR data. The prerequisite for the method to achieve high precision results is the correct detection of common scatterers in SAR images acquired from different viewing geometries. In this contribution, we describe three strategies for automatic detection of identical targets in SAR images of urban areas taken from different orbit tracks. Moreover, a complete work-flow for automatic generation of large number of GCPs using SAR data is presented and its applicability is shown by exploiting TerraSAR-X (TS-X) high resolution spotlight images over the city of Oulu, Finland and a test site in Berlin, Germany.