Executes manner, and this manner which select the phase error which it occurs with the atmosphere in the backscattering signal of the coherent imejireda system which is loaded onto the carrier, from the radar first-hand data the device

摘要

PURPOSE: To obtain an image of high quality by deciding the frequency offset of a back scattering ratio factor from the azimuth spectrum of radar crude data, and obtaining phase error from the decided offset, thereby correcting the error due to the atmosphere such as troposphere, ionosphere. ;CONSTITUTION: Means 20₁ to 20₃ in a broken line section 20 decide frequency offset ΔF(i) or ΔF(t) by the back scattering element of azimuth spectrum by the correlation of two continuous spectra. Next to means 20₃ for forming the maximum of correlation K(f, i), difference forming means 21 for forming the difference between the offset ΔF(t) and predetermined value ΔF_soll of the offset is provided. If the forward speed Vv of the carrier is known, predetermined value ΔF_soll is calculated, while if it is not known, the offset ΔF(t) is displayed as predetermined value Δ F_soll, and passed through a low pass filter 22. Next to the means 21, integrating units 23₁, 23₂ for double integrating the obtained difference are provided, constant 2n/Δt is multiplied in a standardizing unit 24 to obtain a phase difference ψe(t).;COPYRIGHT: (C)1993,JPO