“…Concerning the value of range resolution, it is proportional to the reciprocal of doubled signal bandwidth value, and for GNSS signals, the bandwidth value is equal to the Pseudo-Random Noise (PRN) code chip rate [1,2]. Because the chip rate of GPS C/A code, P code and GLONASS P code are 1.023MHz, 10.023MHz, and 5.11MHz respectively, the range resolutions can be obtained at the levels 150 m, 15 m and 30 m, respectively; for full band Galileo E5 signal, the PRN code chip rate is 51.150MHz, thus the range resolution is achieved at 3 meters level [1][2][3][4][5][6][7][8][9][10][11][12]14,15,17]. Looking at the azimuth resolution of GNSS-SAR, the level less than 1 meter can be achieved [1,2].…”