ALOS-4
Calibration and Validation
Calibration Result of ALOS-3/PALSAR-3 JAXA Standard Products
JAXA/EORC are regularly conducting the calibration and validation of the PALSAR-3 and its standard products using the data over the calibration sites in the world. This page reports evaluation results of the PALSAR-3 standard products and radiometric calibration factors to convert digital number to backscatter value.
ALOS-2/PALSAR-2 Evaluation results are here
https://www.eorc.jaxa.jp/ALOS/en/alos-2/a2_calval_e.htm
Evaluation Results
Notes on the usage of PALSAR-3 standard product
Calibration factor
Digital number in the PALSAR-3 JAXA standard product is converted to backscattering coefficient (sigma naught, sigma zero) using the following equations:
(for L1.5, L2.1)
(for L1.1)
σ0: Backscattering coefficient (Sigma naught or Sigma zero) [unit: dB]
DN: Digital number (or raw pixel value)
CF1, A: Calibration factor [unit: dB]
| Calibration factor | Value [dB] |
|---|---|
| CF1 | -83.0 |
| A | 32.0 |
ALOS-4 Calibration/Validation and Science Team
The ALOS-4 CVST (Calibration/Validation and Science Team) will conduct the following research on calibration/validation of standard products and maintenance of validation data (calibration/validation) as one of the themes of the EORC Earth Observation Research Announcement.
- Methods of calibration, validation, and accuracy improvement for standard products
- Assessing accuracy and applicability of standard products from the initial Cal/Val phase to the beginning of the operational phase
- Development and sharing of high-level products and analysis tools for fundamental applications
- Experiment and demonstration using new features of ALOS-4 such as ionospheric correction mode, extended swath width, and frequent time-series data.
- Research and assessment on cross-calibration with other SAR satellites
- Research on new technology for future missions
| Name | Institution | Research Theme |
|---|---|---|
| Angel Matias Palomeque | CONAE | ALOS-4/PALSAR-3 external calibration and cross-validation with SAOCOM |
| Bernd Scheuchl | University of California, Irvine | Validation of ALOS-4/PALSAR-3 for glacier and ice sheet applications |
| Bruce Chapman | Jet Propulsion Laboratory, California Institute of Technology | Joint calibration activities between NISAR and ALOS-2/ALOS-4 |
| Cunren Liang | Peking University | InSAR algorithm development and product validation for ALOS-2 and ALOS-4 |
| Konstantinos Papathanassiou | German Aerospace Center | Polarimetric (PolSAR) and Polarimetric interferometric (Pol-InSAR) calibration of ALOS-4 data |
| Malin Johansson | UiT The Arctic University of Norway | Calibration and validation of ALOS-2/ALOS-4 for advanced sea ice and oil slick monitoring |
| Marc Thibeault | CONAE | Crops classification, soil moisture and polarimetry with ALOS-4 |
| Masanobu Shimada | Tokyo Denki University | Calibration and validation of PALSAR-3 |
| Ridha Touzi | Canada Centre for Remote Sensing | Calibration of Polarimetric ALOS-4/PALSAR-3 and validation for peatland and permafrost monitoring in Northern Canada |
| Ryo Natsuaki | University of Tokyo | Validation of PALSAR-3 and PALSAR-2 long-term interferometric analysis |
| Tomokazu Kobayashi | Geospatial Information Authority of Japan (GSI) | ALOS-4-based nationwide monitoring of ground deformation |
| Urs Wegmüller | Gamma Remote Sensing AG | ALOS-4 ionosphere correction and cross-sensor interferometry |
| Yohei Kinoshita | University of Tsukuba | Research and development of small displacement detection technique with time-series L-band SAR analysis and its accuracy improvement |