The unprecedented geometric accuracy of the German SAR satellites TerraSAR-X and TanDEM-X raises a new perspective in SAR geolocation. The focus of the present paper is to exploit this unprecedented SAR geolocation accuracy for change detection applications where is not possible to use any reference. This paper presents three specific applications. The first application takes advantage of the along track (AT) baseline of TanDEM-X bistatic data to derive ships 2D velocity. The second application is related to monitor the stability of isolated offshore platforms using TerraSAR-X repeat-pass data. The last one consists on glacier monitoring using a specific deployed Top-Hat reflectors.