M.I. Babokin - Dr.Sci. (Eng), senior scientific officer of the open joint stock company «Corporation «Phasotron-NIIR». E-mail: m.baboki@hotbox.ru
A.V. Efimov - Ph.D. (Eng.), leading engineer of the open joint stock company «Corporation «Phasotron-NIIR». E-mail: alexef@front.ru
O.A. Karpov - Dr.Sci. (Eng), senior scientific officer of the open joint stock company «Corporation «Phasotron-NIIR». E-mail: karp@smtp.ru
M.P. Titov - Ph.D. (Eng.), senior scientific officer of closed joint stock company «Aerocon». E-mail: titovmp@mail.ru

One of the most important applications of modern radar systems of the remote sensing of the Earth are the organization of the interferometric regimes, which ensure obtaining the DEM, monitoring near-boundary territories, unstable slopes, tracking of changes on objects and others. Several versions of interferometers are already known. One more is examined in the article - single-pass interferometer with «chamfered» survey, which is characterized by its simplicity, by flexibility and sufficiently high technical characteristics. The article consists of four parts. The mathematical model of the signal, reflected from the surface during indicated regime, is shown in the first part. Second one represents the algorithm of the estimation of area relief with «chamfered» band survey in two correlated sessions of observation. A phase difference of the signals is divided into four components: the first determines a change in the phase from the angle of incidence. Usually this change in the phase can be calculated and compensated; the second occurs because of the deviation of Doppler signal frequency in two sessions of observation. For the band survey this displacement in the frequency time-constant appears with the beam deflection with respect to the azimuth; third component shows the relative phase shift of paired signals because of the local relief in two sessions of observation. Specifically, this phase deviation is used for evaluating the local relief in each solution element after phase compensation; fourth component of a phase difference determines the relative frequency displacement of paired signals because of the local relief; The measurement of local relief with significant drops in the heights it is advised to use the measurements with several base parameters. The estimation of the theoretical accuracy of measurements is made in the third part of the article. For inclines of surface about 10-15º and with the step of measurements about 20 m accuracy can reach 5-7 m. The results of the experiments, which approve the theoretically calculated accuracy of the proposed interferometer, are given in one fourth part of the article.