Basic performance of space-surface bistatic SAR using BeiDou satellites as transmitters of opportunity

A Novel Range Compression Algorithm for The~Resolution Enhancement in GNSS-SAR

“…Because the terms A r and exp (jφ r (u)) are constants with respect to t, the duration of (4) will be determined by the term Λ (•). Thus the attainable range resolution with respect to pulse duration can be expressed as [1][2][3][4][6][7][8][9][10][11]14,17]…”

“…Through the comparisons, Figure 6(b) has a less range ambiguity because a higher IF value is employed at the GPS receiver. In Figure 6(c), the two scatters located at different range domain cannot be separated on the GNSS-SAR image with the conventional range compression algorithms as the resolution of this approach is 150 m according to (17) with B = 1.023 MHz.…”

“…With the conventional GNSS-SAR imaging algorithm which includes both range and azimuth compression, range resolution is determined by signals bandwidth and bi-static angle for sensing while azimuth resolution is determined by Doppler frequency shift [1][2][3][4][5][6][7][8][9][10][11][12]14,15,17]. But in a numbers of typical literature such as [1][2][3][4][5][6][7][8][9][10][11][12]14,15,17], the system is considered as quasi-monostatic case, which means the bi-static angle can be regarded as zero. Thus the range resolution is merely determined by signal bandwidth among these works.…”

“…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].…”

A Novel Range Compression Algorithm for Resolution Enhancement in GNSS-SARs

“…With a conventional GNSS-SAR imaging algorithm that includes both range and azimuth compression, range resolution is determined by GNSS signal bandwidth and bi-static angle for sensing, while azimuth resolution is determined by Doppler frequency shift [ 1 , 2 , 4 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 ]. However, when the system is considered as a quasi-monostatic case, in which the bi-static angle is and range and azimuth domain are orthogonal, range resolution is mainly decided by the GNSS signal bandwidth [ 1 , 2 , 4 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 ]. If shape factors of a wave form are not considered, potential range resolution identically equals the reciprocal of doubled signal bandwidth value.…”