Concurrent Internal Calibration of Spaceborne SAR Systems

The internal calibration of a SAR instrument is required to guaranty the stability of the hardware over time. Unfortunately most of the current internal calibration schemes cause an interruption of the SAR data acquisition and hence a reduction of the acquisition time for a each target. A novel internal calibration scheme is proposed which allows continuous internal calibration during a data take by injecting a coded signal during the receive window. This is important for future SAR missions allowing data acquisition over large periods of time (several 10 min).The performance of some coding scheme is analyzed also using real TerraSAR-X L0 data.