lo calibration rate discussion
DESCRIPTION
LO calibration rate discussion. UPC/BEC. Reference image. Hawaii. UPC analysis. Differences snapshot to snapshot. Tmeas-Tref. Thermal noise is huge!!. SEPARATING NOISE COMPONENTS. Calibrated visibility:. decimation schemas. interpolated to time meas from cal data. Differences. - PowerPoint PPT PresentationTRANSCRIPT
Remote Sensing LaboratoryUniversitat Politècnica de Catalunya
•Remote•Sensing•Laboratory
LO calibration rate discussion
UPC/BEC
30/May/11-1/June/11 QWG-5 ESRIN 2
Remote Sensing LaboratoryUniversitat Politècnica de Catalunya
•Remote•Sensing•Laboratory
HawaiiU
PC
ana
lysi
s
Reference image
30/May/11-1/June/11 QWG-5 ESRIN 3
Remote Sensing LaboratoryUniversitat Politècnica de Catalunya
•Remote•Sensing•Laboratory
Differences snapshot to snapshot
30/May/11-1/June/11 QWG-5 ESRIN 4
Remote Sensing LaboratoryUniversitat Politècnica de Catalunya
•Remote•Sensing•Laboratory
Tmeas-Tref
Thermal noise is huge!!
30/May/11-1/June/11 QWG-5 ESRIN 5
Remote Sensing LaboratoryUniversitat Politècnica de Catalunya
•Remote•Sensing•Laboratory
j
kj
kjsysjsyskkj eG
MTTV
2)2( j
kj
kjsysjsyskkj eG
MTTV
6)6( j
kj
kjsysjsyskkj eG
MTTV
1)()2()2()( 2 njkjkj
nkj eVVVV
VVV scenekjkj )2(
11 )()( 22 nn jjscenekjn eVeVD
Calibrated visibility:
10)10( j
kj
kjsysjsyskkj eG
MTTV
interpolated to time meas from cal data
decimation schemas
Differences
The visibility has thermal noise:
noisescene TTT then
Error in geophysical signal
Thermal noise component
SEPARATING NOISE COMPONENTS
30/May/11-1/June/11 QWG-5 ESRIN 6
Remote Sensing LaboratoryUniversitat Politècnica de Catalunya
•Remote•Sensing•Laboratory sceneT
30/May/11-1/June/11 QWG-5 ESRIN 7
Remote Sensing LaboratoryUniversitat Politècnica de Catalunya
•Remote•Sensing•Laboratory noiseT
30/May/11-1/June/11 QWG-5 ESRIN 8
Remote Sensing LaboratoryUniversitat Politècnica de Catalunya
•Remote•Sensing•Laboratory noisescene TT
30/May/11-1/June/11 QWG-5 ESRIN 9
Remote Sensing LaboratoryUniversitat Politècnica de Catalunya
•Remote•Sensing•Laboratory
Does averaging cancel the LO phase error?
6min-2min 10min-2min
Spatial structures appear both cross-track and along-track
(Tx+Ty)/2 averaging 0 to 40º incidence angles. Simulation: Vref+phase error
30/May/11-1/June/11 QWG-5 ESRIN 10
Remote Sensing LaboratoryUniversitat Politècnica de Catalunya
•Remote•Sensing•Laboratory
Same effect in real data
6min-2min 10min-2min
The structures are still present
Actual data with decimated calibration
30/May/11-1/June/11 QWG-5 ESRIN 11
Remote Sensing LaboratoryUniversitat Politècnica de Catalunya
•Remote•Sensing•Laboratory
The LO-phase error induces structure in xi-eta
6min-2min
10min-2min
Average of 126 snapshots of TBn-TB2 (actual data)
30/May/11-1/June/11 QWG-5 ESRIN 12
Remote Sensing LaboratoryUniversitat Politècnica de Catalunya
•Remote•Sensing•Laboratory
Conclusions
• LO phase drift produces non-random visibilities errors that translate to brightness temperature spatial structures in xi-eta.
• Relatively small phase error (low standard deviation) may have impact on the image due to this systematic behaviour.
• Simulation data confirms the experimental results. Spatial structures are expected to encounter in SSS retrievals due to imperfect LO phase error cancellation.