'Maximal effective baseline' for conventional SAR interferometry

As is well known, perpendicular baselines coming close to the critical baseline will most likely give poor results or even not give any results in conventional SAR interferometry. In the present paper, we put forward a new concept named 'maximal effective baseline' for conventional SAR interferometry, which is intrinsically different from the concept of 'critical baseline'. It is defined as 'an upper limit of perpendicular baseline for specific SAR system, and it is impossible to obtain necessary coherence to implement conventional SAR interferometry as long as the perpendicular baseline of SAR image pair is beyond this upper limit'. Then, the theoretical approach to determine the maximal effective baseline for conventional SAR interferometry is presented, and the concrete values of maximal effective baselines for ERS1/2 and JERS are yielded by analysing various decorrelation sources. Further more, some InSAR experiments have been made to confirm the results. The 'maximal effective baseline' for conventional SAR interferometry is of practical significance in improving the working efficiency of conventional SAR interferometry.