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| Appendix D. Calibration Constant and Reference Replica Power | |||
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| The influence of Orbit precision in the quality of ERS SAR Interferometry | |||
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Appendix D. Calibration Constant and Reference Replica Power
Appendix D1:PRI Calibration constant K
| ERS-1 | Calibration Constant K | |||
|---|---|---|---|---|
| product processing date | in linear scale | in Decibels | ||
| D-PAF and ESRIN: | ||||
| before 1st September 1992 | 678813 | 58.32 dB | ||
| after 1st September 1992 | 666110 | 58.24 dB | ||
| I-PAF: | ||||
| from 28th June 1993 to 7th December 1994 | 625228 | 57.96 dB | ||
| from 7th December 1994 to 17th March 1995 | 370016 | 55.68 dB | ||
| since 17th March 1995 | 686379 | 58.36 dB | ||
| UK-PAF: | ||||
| before 1st September 1992 | 890107 | 59.49 dB | ||
| from 1st September 1992 to 20th January 1997 | 1072611.2 | 60.30 dB | ||
| since 21st January 1997 | 666110 | 58.24 dB | ||
| ERS-2 | Calibration Constant K | |||
| product processing date | in linear scale | in Decibels | ||
| D-PAF, I-PAF and ESRIN: | ||||
| after 13th July 1995 | 944000 | 59.75 dB | ||
| UK-PAF: | ||||
| from 13th July 1995 to 20 th January 1997 | 1000000 | 60.00 dB | ||
| after 21st January 1997 | 944000 | 59.75 dB | ||
The calibration constant values given above should be used in preference to those in the CEOS header, except that the ERS-2 SAR PRI calibration constant is only valid for data acquisition dates after 13th July 1995. Before this date ERS-2 SAR PRI images are considered uncalibrated.
Appendix D2: SLCI Calibration Constant K
| ERS-1 | Calibration Constant K | |||
|---|---|---|---|---|
| product processing date | in linear scale | in Decibels | ||
| UK-PAF: | ||||
| from 1st September 1992 to 20th January 1997 | 56662.5 | 47.53 dB | ||
| since 21th Jnuary 1997 | 65026.0 | 48.13 dB | ||
| I-PAF, D-PAF and ESRIN: | ||||
| since 21th January 1997 | 65026.0 | 48.13 dB | ||
| ERS-2 | Calibration Constant K | |||
| product processing date | in linear scale | in Decibels | ||
| UK-PAF: | ||||
| from 13th July 1995 to 20th January 1997 | 445656.2 | 56.49 dB | ||
| since 21th January 1997 | 93325.3 | 49.70 dB | ||
| I-PAF, D-PAF and ESRIN: | ||||
| since 21st January 1997 | 93325.3 | 49.70 dB | ||
Appendix D3: Reference Replica Power
| ERS-1 | Reference Replica Power |
|---|---|
| PRI generated at D-PAF, I-PAF and UK-PAF | 205229.0 |
| PRI generated at ESRIN | Chirp average density reference (see below) |
| ERS-2 | |
| generated at D-PAF, I-PAF, UK-PAF and ESRIN | 156000.0 |
- Chirp average density reference: in the case of data products processed at ESRIN (and at D-PAF if the product replica power value is not annotated), the ratio between ProductReplicaPower and ReferenceReplicaPower using equation (2a) shall be replaced by the ratio between first chirp average density measured during image acquisition and chirp average density of reference:
Chirp average density reference:
267.20 for ERS-1 (measured on reference image of 13/10/1991)Chirp average density image: this parameter can be found in the Facility Data Record, PCS type, at byte location: 77+176+3196 = 3449 in the 'ESA reserved' record area. At that location is recorded the first chirp average density over a series of records corresponding to the image acquisition. Because of the low variability of the chirp average density measurements, the first value provides a suitable measurement.
Keywords: ESA European Space Agency - Agence spatiale europeenne, observation de la terre, earth observation, satellite remote sensing, teledetection, geophysique, altimetrie, radar, chimique atmospherique, geophysics, altimetry, radar, atmospheric chemistry