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
- Report ver. 2025.05.25 (Initial Calibration results, in preparation)
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 ice sheet applications |
| Bruce Chapman | Jet Propulsion Laboratory, California Institute of Technology | Evaluation of NISAR calibration targets with ALOS-2 and ALOS-4 imagery |
| Eleanor Ainscoe | Nanyang Technological University | Maximizing potential of ALOS-4 for disaster response in south and southeast Asia |
| Cunren Liang | Peking University | InSAR algorithm development and product validation for ALOS-2 and the upcoming ALOS-4 satellites |
| Howard Zebker | Stanford University | Phase calibration and validation of ALOS-4 data products for InSAR applications |
| 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 | Improved Arctic Sea ice classification, thickness mapping and iceberg detection using a multi-sensor approach |
| Marc Thibeault | CONAE | Crops classification and soil moisture estimation over cropland in Argentina using cross calibration with SAOCOM |
| Masanobu Shimada | Tokyo Denki University | Calibration and validation of PALSAR-3 |
| Masato Furuya | Hokkaido University | Dispersive phases in PALSAR-2/3 InSAR |
| Paul Siqueira | University of Massachusetts | Comparison of ALOS-4 calibration with NISAR |
| Ridha Touzi | Canada Centre for Remote Sensing | Calibration of polarimetric ALOS-4/PALSAR-3 and validation through key applications |
| Ryo Natsuaki | University of Tokyo | Validation of PALSAR-3 and PALSAR-2 interferometric analysis |
| Takenobu Toyota | Hokkaido University | Validation of the algorithm with L-band SAR data for detecting deformed sea ice area in the Arctic Ocean |
| Taku Ozawa | National Research Institute for Earth Science and Disaster Resilience (NIED) | Evaluation of PALSAR-3/InSAR for surface deformation detection |
| Tomokazu Kobayashi | Geospatial Information Authority of Japan (GSI) | ALOS-4-based nationwide monitoring of ground deformation |
| Urs Wegmüller | Gamma Remote Sensing AG | ALOS-4 ionospheric correction and cross-sensor interferometry |
| Yohei Kinoshita | University of Tsukuba | Development of improved InSAR atmospheric delay correction method toward millimeter-accuracy displacement detection and its application for aseismic deformation researches |