SAR Interferometry for Monitoring Neotectonic Movement

          K.S. Rao, Y.S. Rao, G. Venkataraman and M.V. Khire
  CSRE, Indian Institute of Technology, Powai, Mumbai 400 076, India.
      Fax: +91-22-5783480,  Email:  ksrao@disha.csre.iitb.ernet.in

                        ABSTRACT

        There are several well established and recognised geophysical
techniques to comprahend the processes related to seismotectonik
activities.  It has been recently reported that global positioning system
(GPS) can aid in monitoring active fault regions.  More recently a new
techniqe based on microwave remote sensing known as SAR Interferometry
(INSAR) has been emerging as a viable and potential tool for crustal
deformation studies. 

        Through SAR Interferometry, it is possible to estimate topography
of the ground with an accuracy of about five meters.  Differential INSAR
technique involving phase information from three SAR scenes has the
capability to detect very small movement of surface features caused by
crustal deformation and to monitor changes in surface geophysical
parameters. 

        To simulate the earth crust movement, a series of experiments were
conducted near Bhavnagar, Gujarat, India for a period three months during
the tandem operation of ERS-1 and ERS-2 (from April to July 1996).  For
this purpose six corner reflectors were deployed in the field.  The corner
reflectors were mounted on a specially designed stands which has the
ficility to rotate along azimuth and elevation directions.  It can also be
lifted up and down with very high accuracy of reproducibility.  The whole
set-up was installed on a cement base so that the soil swelling can be
eleminated.  The details of these experiments and the other developments
on SAR Interferometry will be discussed in this paper

Keywords: ESA European Space Agency - Agence spatiale europeenne, observation de la terre, earth observation, satellite remote sensing, teledetection, geophysique, altimetrie, radar, chimique atmospherique, geophysics, altimetry, radar, atmospheric chemistry