# Presentation: 556659

## CALVAL - PALSAR

- Masanobu Shimada
- ALOS research Program Manager
- Earth Observation Research and application Center(EORC)
- Japan Aerospace Exploration Agency (JAXA)
- _[shimada.masanobu@jaxa.jp](mailto:Shimada.masanobu@jaxa.jp)_
- CEOS 22th CAL/VAL plenary @ USGS Sioux Falls, SD, USA

## Two failures in 2003 made delays of restarting JAXA space programs. 

- Launcher failure: error analysis and resolving plan were approved by Japan space committee. -> small hole of booster’s nozzle burned the ignition line for separation.
- Satellite failure of ADEOSII: Error analysis is being conducted. Estimated cause is short circuit of the power lines which collect electricity generated by the solar paddle, due to accumulated degradation of the line material by arching and high temperature.

## Slide 3

## CALIBRATION-status (2003 ~ May 2004)

- CAL Meeting at EORC (Sept 16-17 2003):
- Collects the calibration sites world widely. Participants, ALOS PIs and Node delegations(ASF), discussed setting up the available calibration sites from the Initial CAL phase, and availability of the data.
- Calibration algorithm development:
- Image quality evaluation function:
- Absolute calibration coefficients:Use CR and ARCs.
- Antenna pattern estimators, using Amazon rain forest.
- Polarimetric Calibration Algorithm:Use forest data, Corner reflectors, Active radar calibrators.
- Verification Experiments: Use Pi-SAR data acquired over Tomakomai calibration sites (2002-2004).
- Software(SIGMA-SAR) upgrade
- Add functions to Image quality evaluations.
- SCANSAR update (Chirp-z and FFT)
- Calibration procedure evaluated (using Pi-SAR) and implemented.

## Evaluation of the on-ground test data

- 	Chirp replica	-> well collected.
- The other data(End-to-end test) :
- 	 under evaluation.

- I (HH,HV) wave

- Power spectrum

- Range Correlation

- Azimuth pattern of raw data

## Process flow

- L1.0 data(raw data)

- Telemetry analysis and correction

- Doppler/Doppler rate analysis

- Range compress(Chirp rate correction)

- Azimuth compression(SRC)

- range, antenna correction

- 16 bits

- POLCAL
-  distortion correction
-  multilook+16 bits

- 1

- 1

- 2

- 2

- Range migration

- Specan

- Multi look

- Multilook

- 3

- 3

**SCANSAR**

**STRIP**

## Pi-SAR

- Frequency	1.275e9	Hz Band width	50 MHz
- Sampling freq.	61.275MHz
- Height		6~12Km
- Image swath	<=15Km
- AD(I/Q)	8 bits
-  (R)	slant	3 m
-  (A)	4look	3.2 m
- 0		1.1 dB
- NE0		-30 dB
- Inci. Angle	10~60
- Polarimetry	Full
- 		10s
- Pt		3.5KW
- Beam width(A)	8.4 degrees

**Sigma-SAR processor**

**R****:****HH****,****G:HV****,****B:VV**

**Tottori Dune**

- N

## Polarimetric calibration procedure:Implemented in next version.

- Polarimetric calibration procedure:Implemented in next version.

- Dr

- Dt

- UC1.1

- C1.1

- Distortion matrices, Dr, Dt, depend on incidence angle () and time(t).

- Incidence angle dependence of f1, f2,from pi-SAR calibration study.

- Uncalibrated SLC(UC1.1) and calibrated SLC(C1.1) are related by

- Other than Van Zyl and Quegan algorithms, JAXA developed a distributed target based algorithm to determine distortion matrices. The advantages enables incidence angle dependency.
- These matrices (parameters) will be determined several times and evaluated in calibration phase.
- The parameters will be distributed to NODE for data compatibility with JAXA.

- 1.138679e+00 -2.106416e-01 0.000000e+00
- -7.241599e-02 2.510327e-03 0.000000e+00
- 1.346348e+00 -2.288985e-01 0.000000e+00
- 4.468928e-01 -2.510345e-03 0.000000e+00
- -4.602865e-02 7.598560e-02 0.000000e+00
- 1.314591e+00 6.782417e-01 0.000000e+00
- 3.175881e-02 -3.824020e-03 0.000000e+00
- 1.822099e+00 3.960583e-01 0.000000e+00
- 5.389908e-02 -3.755815e-02 0.000000e+00
- 3.381263e+00 -1.072618e+00 0.000000e+00
- -2.499185e-02 8.343484e-02 0.000000e+00
- -7.667590e-01 -8.327003e-01 0.000000e+00

- Dr and Dt:12 scalar parameters (Example)

## 3.0m Corner reflector@Tomakomai forest.

- adjusted for Ascending PALSAR beam 7.
- RCS=38 dBsm, and signal to clutter ratio >=28 dB.

## SIGMA-SAR

- Temporal Change of the Calibration factors

- Six years variation of the calibration factors, PI-SAR

| CF | mean(dB) | std (dB) |
| --- | --- | --- |
| CF1(2002-) | -70.95 | 0.45 |
| A | 69.5 | - |
| CF1(all) | -71.05 | 1.1 |
| CF2 | 5.89 | 0.82 |

- Unit:Decibel
- Refer to the paper:
- M. Shimada, et al.,“Determination of Polarimetric calibration parameters of L band SAR using uniform forest data ,”IGARSS2004, Anchorage, USA

## Uncalibrated

- Calibrated data

- Polarimetric signatures of calibrated and un-calibrated SIGMA-SAR data

## Comparison of the before and after calibration (Forest case)

- Amplitude -> Slightly corrected.
- Phase -> significantly corrected (<2deg.).

- Pi-sar images over tomakomai forest region

- Phase residual error

## PALSAR Calibration sites

- Institute	Type	Numbers	Locations
- JAXA	PARC	1	Hatoyama
- 	CR	2	Tomakomai/Kanto
- CAL PIs	CR	TBD	CCRS(UK+DLR)
- 	CR+PARC	6	JAPAN
- 	CR+ANT	2+4	RUSSIA
- 	CR	5	JPL
- ASF/NOAA	CR	10	ALASKA
- JAXA	Forest	1	Amazon
- JAXA	Ice	2	Greenland/Antarctica

- Distributed target (Antenna)

- Determined sites

- Being determined

## Project Schedule

| Before launch CAL. | Initial mission check | Initial CAL.
 | CAL. |
| --- | --- | --- | --- |

- 3mos

- 5mon

- Launch

- L+9

- Data release

- Data release(limited for PI
- , PDF for general)

- Ver.0

- Ver.1

- Ver.2

- Ver.n

- EOC software version

- Ver.0

- Ver.1

- Ver.n

- EORC software version

- 1 year after

- CAL/VAL review
- march 20 2003

- CAL/VAL review
- DEC 2003

- PI meeting (Jan. 2004)

- CAL/VAL meetings

## Pi-SAR REPEAT PASS InSAR

- SIGMA-SAR

**PRISM**

**AVNIR-2**

**PALSAR**

**Data Relay Antenna**

**Solar Array Paddle**

**Star Tracker**

**GPS Antenna**

**Velocity**

**Nadir**

**PRISM**** ****:  Panchromatic Remote-sensing **
**	****Instrument for Stereo Mapping **
**AVNIR-2: Advanced Visible and Near Infrared Radiometer type 2 **
**PALSAR: Phased Array type L-band Synthetic Aperture Radar **

- ALOS Satellite System

## Summary

- POLCAL procedure has been evaluated and validated using Pi-SAR data and implemented in SIGMA-SAR.
- Calibration procedure has been also evaluated and validated using Pi-SAR data and implemented in the SIGMA-SAR.
- E-to-E and compatibility data will be analyzed in next phase.