page 1 envisat validation workshop - esrin – 9-13 december 2002 asar validation review ap and gm...

ENVISAT Validation Workshop - ESRIN – 9-13 December 2002

ASAR Validation Review

AP and GM Level 0 Product Quality

Birgit Schättler

Remote Sensing Technology InstituteGerman Aerospace Center (DLR)


Objectives and ApproachDownlink Data QualityEcho Data StatisticsDetailed Analysis of an AP Level 0 ProductDetailed Analysis of a GM Level 0 ProductSummary and Conclusions

Overview


Objectives

• ensure, that ASAR AP and GM level 0 products do not show systematic deficiencies

• start the quantitative analysis of raw data parameters like echo data statistics, noise measurements, …


Approach• 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 based on CBTS (“Chris Buck Tool Set”)

• Perform a detailed analysis of selected level 0 products using SARCON, an off-line SAR product quality analysis software


AP Systematic Analysis

AP systematic analysis based on annotations of 106 products only : 57 APM, 49 APP

18 IS 1 : 1 VH 8 VV VH 9 HV HH, 24 IS 2 : 3 HH 13 VV VH 5 HV HH 3 VV HH8 IS 3 : 2 VH 6 VV VH22 IS 4 : 2 VH 4 HH 8 VV VH 8 HV HH16 IS 5 : 2 VH 6 VV VH 8 HV HH8 IS 6 : 5 VV VH 3 HV HH10 IS 7 : 3 VV VH 7 HV HH


AP Downlink Data Quality Summary• missing range lines detected in 3 products:

1 with 7 missing, 2 with 1 missing each

• product with 7 missing range lines has 2 corrupted auxiliary codes, all other products show no auxiliary code error at all

• missing lines percentage = 0.00014 % (9 missing out of 6392012)

Good downlink data quality can be assumed


I and Q Channel Bias

IS 2 - I Channel Bias

0.0014

0.0015

0.0016

0.0017

0.0018

0.0019

0.002

0 2 4 6 8 10 12 14 16 18 20

bias

VV from VV_VH

VH from VV_VH

HV from HV_HH

HH from HV_HH

HH

IS 2 - Q Channel Bias

0.0014

0.0015

0.0016

0.0017

0.0018

0.0019

0.002

0 2 4 6 8 10 12 14 16 18 20

bias

VV from VV_VH

VH from VV_VH

HV from HV_HH

HH from HV_HH

HH

IS 1 - Q Channel Bias

0.0014

0.0015

0.0016

0.0017

0.0018

0.0019

0.0020.0021

0.0022

0 1 2 3 4 5 6 7 8 9 101112131415161718

bias

VV from VV_VHVH from VV_VH

HV from HV_HH

HH from HV_HH

IS 1 - I Channel Bias

0.0014

0.0015

0.0016

0.0017

0.0018

0.0019

0.002

0.0021

0.0022

0 1 2 3 4 5 6 7 8 9101112131415161718

bias

VV from VV_VH

VH from VV_VH

HV from HV_HH

HH from HV_HH


I / Q Channel Standard Deviation

IS 7 - Q / I Channel Standard Deviation

0.12

0.13

0.14

0.15

0.16

0.12 0.13 0.14 0.15 0.16

I standard deviation

Q s

tand

ard

devi

atio

n

VV from VV_VHVH from VV_VH

HV from HV_HH

HH from HV_HH

IS 2 - Q / I Channel Standard Deviation

0.07

0.08

0.09

0.1

0.11

0.12

0.07 0.08 0.09 0.1 0.11 0.12

stan

dard

dev

iatio

n

VV from VV_VH

VH from VV_VH

HV from HV_HH

HH from HV_HH

HH


Noise Power Correction Factor

IS 2 -Noise Power Correction Factor

0.0004

0.0005

0.0006

0.0007

0 2 4 6 8 10 12 14 16 18 20

nois

e po

wer

cor

rect

ion

VV from VV_VH

VH from VV_VH

HV from HV_HH

HH from HV_HH


Detailed Analysis of an AP IS 2 Product• ASA_APH_0PNPDK20021106_094707_0000008920

11_00022_03583_0043.N1

• Netherlands calibration site with transponders in H/V and H/H polarisation, beam IS 6

• “nominal timeline anomaly”

• no anomalies observed


Downlink Data Quality• no missing / erroneous ISPs

• no missing range lines

• no errors in analysed auxiliary codes

perfect downlink data quality


AP Timeline (Initial Cycle)• initial noise : 8 lines in HV and 8 lines in HH

• initial calibration sequence : 97 pulses in HV and 97 pulses in HH

• pre-flight observed anomaly in periodic cycle is now the nominal case handled by PF_ASAR

timeline according to expectation


AP Timeline (Periodic Cycles)pre-flight observed

237 echo + 1 cal in HV237 echo in HH237 echo in HV238 echo in HH-----------------------238 echo in HV237 echo + 1 cal in HH238 echo in HV238 echo in HH-----------------------237 echo + 1 cal in HV237 echo in HH237 echo in HV 238 echo in HH-----------------------. . . . . .

specified

237 echo + 1 cal in HV238 echo in HH238 echo in HV238 echo in HH-----------------------238 echo in HV237 echo + 1 cal in HH238 echo in HV238 echo in HH-----------------------237 echo + 1 cal in HV238 echo in HH238 echo in HV 238 echo in HH-----------------------. . . . . .


Echo Data Histograms and Statistics

HH polarisation I Bias = 0.001765 Q Bias = 0.001854 I Stddev = 0.122002 Q Stddev = 0.121865 IQ Gain imbalance = 1.001119 IQ Non-orthogonality = 0.004364

HV polarisation I Bias = 0.001730 Q Bias = 0.001793 I Stddev = 0.051607 Q Stddev = 0.051510 IQ Gain imbalance = 1.001875 IQ Non-orthogonality = 0.003519

I channel

Q channel

I channel

Q channel• no echo data saturation

• dynamic range not fully used


Echo Data Visual Inspection

no anomalies observedHH HV


Range-Compressed Data Visual Inspection

HH HVno anomalies observed


Detailed Analysis of a GM Product• ASA_GM__0PNPDK20021114_071147_0000010620

11_00135_03696_0211 in VV polarization

• region in the north of Russia

• anomaly observed with instrument characterization file : wrong subsampling factors for beam SS2 … SS5corrected INS file delivered by ESRIN


GM1 Product


Downlink Data Quality• no missing or erroneous source packet

• 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


Echo Data Histogram

• no echo data saturation• dynamic range not fully used

Q

I

SS1 SS5


Echo Data Statistics

swath SS1:

I Bias = 0.001516, Q Bias = 0.001479 I Stddev = 0.070892, Q Stddev = 0.070799 IQ Gain imbalance = 1.001307, IQ Non-orthogonality = 0.002945

swath SS5: I Bias = 0.001495, Q Bias = 0.001429 I Stddev = 0.080410, Q Stddev = 0.080333 IQ Gain imbalance = 1.000956, IQ Non-orthogonality = 0.001402


Echo Data Visual Inspection

SS1


Range-Compressed Data Visual Inspection

SS1


Initial Calibration Pulses

SS1

P1 P1A

P3P2


Periodic Calibration Pulses

SS1 P1 P1A P3P2


Summary and Conclusions (I)• Analysed AP and GM level 0 products show a good

overall product quality.

• First AP quantitative measurement results could be obtained, but based on a small variety of products only

• Only one GM product available


Summary and Conclusions (II)• Detailed analysis of selected level 0 products will

be done only for “suspicious” products in the future

• The operational PDS tool for a systematic and automatic parameter evaluation is urgently needed- as indicator for possible anomalies - for further overall quality assessment - for further quantitative measurements

page 1 envisat validation workshop - esrin – 9-13 december 2002 asar validation review ap and gm...

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