1. Constellation of Airbus SAR satellites and PHOTOMOD Radar software: quality assessment of geometric and radiometric parameters of TerraSAR-X imagery Matthieu Besnard, Head of Channel Partner Programm Airbus DS Geo–Intelligence, France Aleksander Chekurin, Commercial Director Aleksander Chekurin, Commercial Director Racurs, Russia From Imagery to Map: Digital Photogrammetric Technologies 15 th International Scientific and Technical Conference From Imagery to Map: Digital Photogrammetric Technologies Yucatan. Mexico. October 2015

2. Some of validated parameters of satellite RSD systems Impulse response characteristics related to the capability of RSD system to image objects with different geometrical dimensions including the critical ones (linear ground resolution) Coordinate measuring characteristics which determine the image measurement properties and the accuracy of image key-elements Radiometric characteristics related to the capability of RSD system to reproduce the radiometric properties of objects General system characteristics which determine the capability of RSD space system to collect information

3. Resolution test chart (test object 1) Potential test chart (test object 2) Single corner reflectors (markers): center marker – 1 pce boundary markers – 4 pcs Test object 1: resolution test chart – 9 corner reflectors Test object 2: radiometric (potential) test chart – 14 corner reflectors The set of the corner reflectors 3 Test field equipment The layout of the test objects Ilovlinsky District Volgograd region The test field for evaluation of RSD system characteristics

4. The test field of the validation measurements

5. Adjustment of the corner reflectors The corner reflectors on the test field

6. кл The corner reflectors

7. Characteristics of the corner reflectors RCS (S-band), dBSize, mRCS (X-band), sq.mRCS (X-band), dB 452,88830196454,80 402,16695489,549,80 351,62430196,444,80 301,2189548,9539,80 250,9133019,6434,80 240,8622398,5933,80 200,685954,89529,80 150,514301,96424,80 100,38595,489519,80 50,28930,196414,80 00,2179,548959,800 -50,1623,019644,800 -100,1220,95490-0,200 -200,0680,09549-10,20.

8. The layout drawing of the corner reflectors on the test field Radar image of the test field The layout drawing of the corner reflectors

9. The final acquisition plan ModeStart TimeIncidence Angle RangeOrbitBeam IDPass Direction ST2015-05-22T14:42:11.29726.73 – 26.7384spot_022RA ST2015-05-21T14:59:18.48450.35 – 50.3569spot_083RA ST2015-05-20T02:59:33.68357.74 – 57.7446spot_112RD HS2015-05-24T0325:15.44326.04 – 26.04107spot_020RD HS2015-05-25T03:08:08.36349.94 – 49.94122spot_082RD Organization of survey

10. TerraSAR-X imagery analysis Scene TSX1_SAR__SSC______ST_S_SRA_20150520T030011_20150520T030011 A fragment with test charts of corner reflectors (green rectangle - resolution test chart, orange - radiometric test chart)

11. 1 9 2 3 4 5 6 7 8 9 6 8 1 5 7 3 2 4 4 1 2 3 5 6 9 8 7 The radar imagery fragments of resolution test chart in ST mode

12. 1 2 4 7 5 6 8 9 3 4 7 2 3 5 6 8 9 1 The radar imagery fragments of resolution test chart in HS mode

13. The pulse response sections of corner reflectors of resolution test chart Corner reflector 1 reference signal signal interpolated in the frequency domain signal interpolation by Gaussian function Slant rangeAzimuth range

14. Response amplitudes of resolution test chart in 3D

15. Pulse response for the central point Original response Interpolated signal

16. 16 Meaning of abbreviations used in the table: D R (F) – slant range resolution which was estimated using the signal interpolation in the frequency domain, meters; D R (G) – slant range resolution which was estimated using the signal interpolation by Gaussian function, meters; D Az (F) – azimuth resolution which was estimated using the signal interpolation in the frequency domain, meters; D Az (G) – azimuth resolution which was estimated using the signal interpolation by Gaussian function, meters; SL R (R) – first right sidelobe level in slant range; SL R (L) – first left sidelobe level in slant range; SL Az (R) – first right sidelobe level in azimuth; SL Az (L) – first left sidelobe level in azimuth; M – average value of characteristic over the scene; RMS - mean square deviation of characteristic evaluation over the scene; M S – average value of characteristics over the all scenes for mode; RMS S – mean square deviation of characteristic evaluation over the all scenes for mode. Pulse response analysis was carried out over the area of 32 x 32 pixels with a peak response in the middle of the area. Results of meents Results of measurements Pulse response characteristics of TerraSAR-X measured with use of PHOTOMOD Radar

17. 17 D R (F)D R (G)D Az (F)D Az (G)SL R (L)SL R (R)SL Az (L)SL Az (R) Scene TSX1_SAR__SSC______ST_S_SRA_20150520T030011_20150520T030011 M 0,6016300,5818880,2390260,225880-31,6343-28,7160-28,7782-33,7229 RMS 0,0052300,0154880,0027730,0122641,81092,24093,17254,3117 Scene TSX1_SAR__SSC______ST_S_SRA_20150521T145956_20150521T145956 M 0,6012450,5787210,236790,227369-36,7838-30,912-28,9243-30,0423 RMS 0,0071060,0065090,0025740,0120495,9070956,0023282,7755896,37658 Scene TSX1_SAR__SSC______ST_S_SRA_20150522T144249_20150522T144249 M 0,6026740,573620,2352900,221753-39,0070-32,7524-37,3284-32,9516 RMS 0,0015690,0154940,0028280,0099147,2487536,09576710,104027,358993 Average values for ST mode MSMS 0,6018500,5780760,2370350,225001-35,8084-30,7935-31,677-32,2389 RMS S 0,0046350,0124970,0027250,0114094,9889164,7796655,3507026,015758 Scene TSX1_SAR__SSC______HS_S_SRA_20150524T032553_20150524T032554 M 0,5988300,5665331,1857581,113123-37,3204-31,4552-33,9937-37,4095 RMS 0,0028040,0141890,0120970,0318069,314434,822283,7600086,390421 Scene TSX1_SAR__SSC______HS_S_SRA_20150525T030846_20150525T030847 M 0,6011960,5668871,1840081,106669-36,9381-33,8193-28,8693-34,8804 RMS 0,0064810,0232670,009460,0259229,0980277,49472322,710315,563505 Average values for HS mode MSMS 0,6000130,566711,1848831,109896-37,1292-32,6373-31,4315-36,1449 RMS S 0,0046430,0187280,0107780,0288649,2062286,15850113,235165,976963 The results of measurements of pulse response characteristics Slant range resolutionAzimuth resolution

18. Dependency of pulse responses from the RCS of the reflectors The amplitudes of the linear part of pulse responses Three-dimensional representation of the linear part of pulse responses

19. In the windows are marked only the reflectors forming "the ideal response line" and participating in the evaluation of the radiometric characteristics. Red and green rectangles shows areas of the image used in the evaluating of the relative radiometric error, blue - in the evaluation of the radiometric resolution and the effective number of looks. The saturation begins with RCS of 34.8 dB The measurement results of radiometric characteristics of SAR TerraSAR-X

20. Acquisition date Radiometric error, dB Radiometric linearity Effective number of looks Radiometric resolution, dB Noise equivalent, dB Dynamic range, dB HS mode 24.05.20150,007580,9895860,9978273,01266-19,061,6149 25.05.20150,151730,9990800,9256333,09501-19,062,9973 Mean0,079650,9943330,9617303,05383-19,062,3061 MSD0,101920,0067130,0510480,058230,00,97750 ST mode 20.05.20150,088240,9980510,9583333,05675-18,054,3832 21.05.20150,129180,9972210,9778123,03473-18,053,4838 22.05.20150,034670,9965420,9340333,08503-18,052,1196 Mean0,084030,9972710,9567263,05883-18,053,3288 MSD0,047390,0007560,0219340,025210,01,139726

21. Conclusions Measurements of pulse response characteristics confirm the claimed spatial resolution of TerraSAR-X data Measurements of radiometric parameters shows the high radiometric quality of TerraSAR-X imagery

22. Thank you for your attention!