[S-TT39] Synthetic Aperture Radar and its application

[STT39-01] Conditions for SAR Interferometry

*Mikio Tobita¹, Ryoichi Furuta¹, Satoshi Fujiwara², Tomokazu Kobayashi² (1.Remote Sensing Technology Center of Japan, 2.Geospatial Information Authority of Japan)

Keywords:synthetic aperture radar interferometry, critical baseline, derivation

We introduce a simple derivation of calculation formula of critical baseline. Perpendicular baseline of a SAR image pair is a key factor in conventional SAR interferometry (InSAR) because it strongly influences the coherence of SAR interferogram. Critical baseline is the upper limit of the perpendicular baseline in InSAR and has had a great influence on design and orbit control of SAR satellites and InSAR processing strategy. The calculation formula of critical baseline was introduced in 1980’s and has been slightly modified in its appearance in the later articles. These articles are very important and have played significant role. However, it is not easy to extract the derivation from long articles which purposes and conditions differ. Moreover, the derivation of the formula slightly differs each other and very complicated. A new simple derivation of calculation formula of critical baseline is based on differential of composite function. We will show the reason for using composite-function differential rule, comparison of the critical baseline of satellites, and InSAR critical gradient of crustal deformation at the meeting.