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ASAR Calibration Review Level 0 Products

ASAR Calibration Review Level 0 Products Birgit Schättler Remote Sensing Technology Institute German Aerospace Center (DLR). Overview. Objectives and Approach Downlink Data Quality Echo Data Statistics Noise Data Measurements Detailed Analysis of an Image Mode Level 0 Product

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ASAR Calibration Review Level 0 Products

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  1. ASAR Calibration Review Level 0 Products Birgit SchättlerRemote Sensing Technology InstituteGerman Aerospace Center (DLR)

  2. Overview Objectives and Approach Downlink Data Quality Echo Data Statistics Noise Data Measurements Detailed Analysis of an Image Mode Level 0 Product Detailed Analysis of a Wide-Swath Mode Level 0 Product Detailed Analysis of a Wave Mode Level 0 Product Summary and Conclusions

  3. ensure, that ASAR level 0 products do not show systematic deficiencies start the quantitative analysis of raw data parameters like echo data statistics, noise measurements, … Note, that anomalies found with respect to sensor / telemetry issues are mostly reported in another talk current investigations focus on IM, WS and WV modes in VV polarisation Objectives

  4. Evaluate systematically and automatically level 1B product annotation parameters related to level 0 product quality (e.g. downlink data quality, echo data statistics, noise measurements ) using a tool incorporated into the PDS functionality not yet available => only restricted systematic analysis possibilities Perform a detailed analysis of selected level 0 products using SARCON, an off-line SAR product quality analysis software Approach

  5. Only 1 out of 50 analysed WV level 0 products showed a significant number of missing and erroneous source packets.48 products showed neither missing nor erroneous source packets. 225 analysed IMM products showed no missing range lines. statistics on WSM not yet available => Good downlink data quality assumed Downlink Data Quality

  6. echo data statistics retrieved from 225 IMM products9 IS1, 115 IS2, 14 IS3, 9 IS4, 17 IS5, 42 IS6, 19 IS7 echo data statistics retrieved from 2787 WVI imagettes754 IS1, 789 IS2, 0 IS3, 71 IS4, 403 IS5, 405 IS 6, 365 IS7 no anomalies observed Image and Wave Mode Echo Data Statistics

  7. Image Mode I and Q Channel Bias

  8. Wave Mode I and Q Channel Bias (I)

  9. Wave Mode I and Q Channel Bias (II)

  10. Wave Mode I and Q Channel Bias (III)

  11. Wave Mode Q / I Channel Standard Deviation (I)

  12. Wave Mode Q / I Channel Standard Deviation (II)

  13. average noise power retrieved from 2787 imagettes(754 IS1, 789 IS2, 0 IS3, 71 IS4, 403 IS5, 405 IS 6, 365 IS7)IS 1 -29.10 dB IS 2 -32.18 dBIS 4 -30.42 dB IS 5 -30.07 dBIS 6 -29.37 dB IS 7 -28.27 dB Wave Mode Noise Data Analysis

  14. ASA_IM__0PNPDK20020802_100404_000001092008_00151_02209_0458.N1ASA_IM__0PNPDK20020802_100404_000001092008_00151_02209_0458.N1 Netherlands calibration site with transponders in VV polarisation no anomalies observed Detailed Analysis of an IM IS 2 Product

  15. no missing / erroneous ISPs no missing range lines no errors in analysed auxiliary codes => perfect downlink data quality Downlink Data Quality

  16. initial noise sequence : 8 noise lines initial calibration sequence : 97 pulses periodic calibration sequence : 176 packets with 704 pulses (each 1024th packet) 180750 echo lines number of total source packets: 8 + 97 + 176 + 180750 = 181031 => timeline according to specification Timeline Analysis

  17. no echo data saturation dynamic range not fully used Echo Data Histogram

  18. Echo Data Visual Inspection no anomalies observed

  19. Range-Compressed Data Visual Inspection

  20. Calibration Pulse Embedding Initial Calibration Pulse 2 Matrix Calibration pulses do not “fit” into their embedding window, see magnitude and phase plot over window below => careful reconstruction necessary

  21. ASA_WS__0PNPDK20020726_140228_000000992008_00053_02111_1011.N1ASA_WS__0PNPDK20020726_140228_000000992008_00053_02111_1011.N1 Amazonian rain forest in VV polarisation an anomaly with respect to missing ISPs observed Detailed Analysis of a WS Products

  22. 78 missing instrument source packets (ISP) reported in MPH 444 sub-swath SS2 burst available, first 405 are okay, last 39 bursts show systematic error: last echo line and periodic cal pulse ISP are missing further analysis necessary periodic calibration cycle interrupted => impact on calibration pulse processing 1 out of 80 echo lines per SS2 burst possibly missing => no further impact on echo data processing Missing Source Packets

  23. initial noise sequences : 8 noise lines for each sub-swath : OKAY initial calibration pulse sequences : 97 calibration pulses for each sub-swath : OKAY periodic noise sequences : no anomaly observed, but further analysis necessary periodic calibration sequences : see missing ISP anomaly in SS 2 otherwise : no anomaly observed Timeline Analysis

  24. no single error in analysed auxiliary codes (PRI, SWST, SWL, up/down converter, TX pulse length, TX pulse bandwidth, resampling factor) => apart from the missing source packet anomaly : perfect downlink data quality Detailed analysis of a second WS level 0 product showed no missing ISPs and perfect downlink data quality. Downlink Data Quality

  25. Echo Data Histograms (I)

  26. Echo Data Histograms (II)

  27. Echo Data Histograms (III)

  28. Initial Noise Data Inspection SS1 SS2 SS3 SS4 SS5

  29. Periodic Noise Data Inspection SS1 SS4

  30. average periodic noise power values:SS 1 0.0008 -30.97 dB SS 2 0.0010 -30.00 dBSS 3 0.0011 -29.59 dB SS 4 0.0012 -29.21 dB SS 5 0.0014 -28.54 dB Periodic Noise Data Measurement

  31. Estimated baseband Doppler values over range show Doppler offset between beams Baseband Doppler Estimation

  32. ASA_WV__0PNPDK20020703_142118_000005862007_00225_01782_0409.N1ASA_WV__0PNPDK20020703_142118_000005862007_00225_01782_0409.N1 Amazonian rain forest beams IS 1 and IS 2 in VV polarisation 20 wave vignettes per beam no anomalies observed so far Detailed Analysis of a WV Products

  33. no missing source packets no missing range lines no single error in analysed auxiliary codes (PRI, SWST, SWL, up/down converter, TX pulse length, TX pulse bandwidth, resampling factor) => perfect downlink data quality Downlink Data Quality

  34. Echo Data Visual Inspection no anomalies observed IS2 No. 10 IS1 No. 6

  35. no echo data saturation Echo Data Histograms • 2-bit FBAQ • dynamic range not fully used

  36. Analysed IM, WS and WV level 0 products show a good overall product quality. First IM, WS and WV quantitative measurement results could be obtained, but need further refinement based on a larger variety of products. Cal pulse embedding and systematic missing ISP observed - but can be handled properly during level 1 processing. Summary and Conclusions (I)

  37. Detailed analysis of selected level 0 products to be continued The operational PDS tool for a systematic and automatic parameter evaluation is urgently needed- as indicator for possible further anomalies - for further overall quality assessment - for further quantitative measurements Summary and Conclusions (II)

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