Inter-satellites radiometric calibration status of COSMO-SkyMed constellation

Transcription

1 Inter-satellites radiometric calibration status of COSMO-SkyMed constellation CEOS SAR 2015 Valerio Grimani, Pasquale Salemme DOC-TAS-EN-003

2 Summary COSMO-SkyMed Overview 2 El Sosneado COSMO-SkyMed Campaign Inter-satellites calibration assessment Radiometric performances Conclusions Unknown calibrators characterization by means of COSMO-SkyMed data

3 COSMO-SkyMed overview COSMO-SkyMed (Constellation of Small Satellites for Mediterranean basin Observation) is a 4-satellite constellation funded by ASI (Agenzia Spaziale Italiana) and Italian MoD. The overall objective is the global Earth observation and the relevant data exploitation for the needs of the military community as well as for the civil community (Dual Use). Thales Alenia Space Italia is the prime contractor of the end-to-end system and leads an industrial team of small and medium sized Italian companies including many from the Finmeccanica group, including Telespazio which is responsible for the Ground Segment design and development. 3

4 COSMO-SkyMed overview 8 th December th November th June th October 2008 The satellites were launched from the Vandenberg Air Force base in California, on board a Boeing Delta II launchers. 4 satellites equipped with High resolution, X-band imaging radar (SAR) with > 2 x 650 km ground access Sun-synchronous orbit for satellites operation km altitude Global Earth access (including polar caps) with all weather / night-daylight sensing capability

5 COSMO-SkyMed overview Courtesy of ASI, All rights reserved 5 NARROW FIELD SPOTLIGHT 1m Resolution (10km x 10 km) Courtesy of ASI, All rights reserved SPOTLIGHT (high resolutions over small images) WIDE FIELD HIMAGE 3 m x 3 m Resolution (40km x 40 km) PINGPONG 15 m x 15 m Resolution (30 km x 30 km) WIDEREGION 30 m x 30 m Resolution (100 km x 100 km) HUGEREGION 100 m x 100 m Resolution (200 km x 200 km) STRIPMAP (high to medium resolution over tenth of km images) Courtesy of ASI, All rights reserved SCANSAR (medium to coarse resolution over large swath)

6 El Sosneado COSMO-SkyMed Campaign Scope: to trace a state of current radiometric performances proposing an inter-satellites calibration report among the four SAR sensors 6 Unknown calibrators characterization by means of COSMO-SkyMed data

7 El Sosneado COSMO-SkyMed Campaign Scope: to trace a state of current radiometric performances proposing an inter-satellites calibration report among the four SAR sensors 7 Action: El Sosneado (Mendoza, Argentina) site campaign: 12 trihedral corner reflectors deployed in not sensitive sites, outside the Italian country Not impacts on usability of the system by users Entire COSMO-SkyMed constellation used Different SAR modes Different access angles Large amount of data collection Unknown calibrators characterization by means of COSMO-SkyMed data

8 HIMAGE mode: inter-satellites calibration performances 8

9 HIMAGE VV mode: inter-satellites calibration performances RCS statistics: COSMO-SkyMed 1 mean : dbm2 COSMO-SkyMed 2 mean : dbm2 COSMO-SkyMed 3 mean : dbm2 COSMO-SkyMed 4 mean : dbm2 } CSK HIMAGE VV RCS std 0.09 db 9

10 HIMAGE HH mode: inter-satellites calibration performances RCS statistics: COSMO-SkyMed 1 mean : dbm2 COSMO-SkyMed 2 mean : dbm2 COSMO-SkyMed 3 mean : dbm2 COSMO-SkyMed 4 mean : dbm2 } CSK HIMAGE HH RCS std 0.11 db 10

11 SPOTLIGHT mode: inter-satellites calibration performances 11

12 SPOTLIGHT VV mode: inter-satellites calibration performances RCS statistics: COSMO-SkyMed 1 mean : dbm2 COSMO-SkyMed 2 mean : dbm2 COSMO-SkyMed 3 mean : dbm2 COSMO-SkyMed 4 mean : dbm2 } CSK SPOTLIGHT VV RCS std 0.23 db 12

13 SPOTLIGHT HH mode: inter-satellites calibration performances RCS statistics: COSMO-SkyMed 1 mean : dbm2 COSMO-SkyMed 2 mean : dbm2 COSMO-SkyMed 3 mean : dbm2 COSMO-SkyMed 4 mean : dbm2 } CSK SPOTLIGHT HH RCS std 0.13 db 13

14 PINGPONG mode: inter-satellites calibration performances 14

15 PINGPONG VV mode: inter-satellites calibration performances RCS statistics: COSMO-SkyMed 1 mean : dbm2 COSMO-SkyMed 2 mean : dbm2 COSMO-SkyMed 3 mean : dbm2 COSMO-SkyMed 4 mean : dbm2 } CSK PINGPONG VV RCS std 0.08 db 15

16 PINGPONG HH mode: inter-satellites calibration performances RCS statistics: COSMO-SkyMed 1 mean : dbm2 COSMO-SkyMed 2 mean : dbm2 COSMO-SkyMed 3 mean : dbm2 COSMO-SkyMed 4 mean : dbm2 } CSK PINGPONG HH RCS std 0.12 db 16

17 SCANSAR mode: inter-satellites calibration performances 17

18 SCANSAR WR VV mode: inter-satellites calibration performances RCS statistics: COSMO-SkyMed 1 mean : dbm2 COSMO-SkyMed 2 mean : dbm2 COSMO-SkyMed 3 mean : dbm2 COSMO-SkyMed 4 mean : dbm2 } CSK SCANSAR WR VV RCS std 0.23 db 18

19 SCANSAR WR HH mode: inter-satellites calibration performances RCS statistics: COSMO-SkyMed 1 mean : dbm2 COSMO-SkyMed 2 mean : dbm2 COSMO-SkyMed 3 mean : dbm2 COSMO-SkyMed 4 mean : dbm2 } CSK SCANSAR WR HH RCS std 0.27 db 19

20 Trihedral corner reflector EM model RCS expected values w.r.t. angle on corner evaluated by using data provided by CONAE: TCR Elevation = RCS peak ~47.7 ~35 20

21 COSMO-SkyMed RCS VV Measurements v.s. TCR EM model COSMO-SkyMed radiometric accuracy requirement of 1 db RCS measurements: CSK HIMAGE radiometric accuracy: 0.14 db (17 products) 21

22 COSMO-SkyMed RCS VV Measurements v.s. TCR EM model COSMO-SkyMed radiometric accuracy requirement of 1 db RCS measurements: CSK HIMAGE radiometric accuracy: 0.14 db (17 products) CSK SPOTLIGHT radiometric accuracy: 0.29 db (15 products) 22

23 COSMO-SkyMed RCS VV Measurements v.s. TCR EM model COSMO-SkyMed radiometric accuracy requirement of 1 db RCS measurements: CSK HIMAGE radiometric accuracy: 0.14 db (17 products) CSK SPOTLIGHT radiometric accuracy: 0.29 db (15 products) CSK PINGPONG radiometric accuracy: 0.18 db (12 products) 23

24 COSMO-SkyMed RCS VV Measurements v.s. TCR EM model COSMO-SkyMed radiometric accuracy requirement of 1 db RCS measurements: CSK HIMAGE radiometric accuracy: 0.14 db (17 products) CSK SPOTLIGHT radiometric accuracy: 0.29 db (15 products) CSK PINGPONG radiometric accuracy: 0.18 db (12 products) CSK SCANSAR WR radiometric accuracy: 0.24 db (23 products) 24

25 COSMO-SkyMed RCS HH Measurements v.s. TCR EM model COSMO-SkyMed radiometric accuracy requirement of 1 db RCS measurements: CSK HIMAGE radiometric accuracy: 0.15 db (27 products) 25

26 COSMO-SkyMed RCS HH Measurements v.s. TCR EM model COSMO-SkyMed radiometric accuracy requirement of 1 db RCS measurements: CSK HIMAGE radiometric accuracy: 0.15 db (27 products) CSK SPOTLIGHT radiometric accuracy: 0.28 db (18 products) 26

27 COSMO-SkyMed RCS HH Measurements v.s. TCR EM model COSMO-SkyMed radiometric accuracy requirement of 1 db RCS measurements: CSK HIMAGE radiometric accuracy: 0.15 db (27 products) CSK SPOTLIGHT radiometric accuracy: 0.28 db (18 products) CSK PINGPONG radiometric accuracy: 0.41 db (15 products) 27

28 COSMO-SkyMed RCS HH Measurements v.s. TCR EM model COSMO-SkyMed radiometric accuracy requirement of 1 db RCS measurements: CSK HIMAGE radiometric accuracy: 0.15 db (27 products) CSK SPOTLIGHT radiometric accuracy: 0.28 db (18 products) CSK PINGPONG radiometric accuracy: 0.41 db (15 products) CSK SCANSAR WR radiometric accuracy: 0.34 db (21 products) 28

29 Opportunity Targets: inter-satellites calibration performances COSMO-SkyMed HIMAGE mode products over permanent scatterers Four opportunity targets of the same scene have been considered 29 COSMO SkyMed - 1

30 Opportunity Targets: inter-satellites calibration performances COSMO-SkyMed HIMAGE mode products over permanent scatterers Four opportunity targets of the same scene have been considered 30 COSMO SkyMed - 2

31 Opportunity Targets: inter-satellites calibration performances COSMO-SkyMed HIMAGE mode products over permanent scatterers Four opportunity targets of the same scene have been considered 31 COSMO SkyMed - 3

32 Opportunity Targets: inter-satellites calibration performances COSMO-SkyMed HIMAGE mode products over permanent scatterers Four opportunity targets of the same scene have been considered 32 COSMO SkyMed - 4

33 Opportunity Targets: inter-satellites calibration performances COSMO-SkyMed HIMAGE mode products over permanent scatterers Four opportunity targets of the same scene have been considered 33 CSK std 0.19 db CSK std 0.12 db CSK std 0.24 db CSK std 0.12 db

34 Conclusion & Acknowledgements Based on data acquired with a dedicated campaign on well-known calibration sites, the RCS measurements obtained with the four Satellites of COSMO-SkyMed constellation demonstrate the alignment of values measured by varying the SAR sensors and acquisition geometries. 34 The achieved inter-satellites radiometric alignment during the commissioning phases of the four satellites of the constellation can be then considered fully preserved. Even though three satellites are beyond their expected end of life, the constellation can be considered still fully operative and calibrated. The data used in this assessment are only a subset of a campaign that has lasted more than three years and that is still on going, being part of COSMO-SkyMed performances monitoring. A special thanks to ASI and CONAE for the availability of data and calibration site.

35 Thank you for your attention! 35 ESTEC - Noordwijk, Netherlands COSMO-SkyMed Spotlight Product Processed by Thales Alenia Space