Research Announcement
Data Products [APPENDIX A-3]
1. Definition of ALOS Data Products
Three categories of data products are defined - Raw or Level 0 data, level 1 products and higher level products.
1.1 Raw data or Level 0 data
Raw data is the demodulated bit stream and is temporarily archived in NASDA. Level 0 data is frame-synchronized, de-packetized decoding data. This level 0 data is permanently archived in NASDA and is for distribution to ALOS data node organizations.
1.2 Level 1
Level 1 is radiometrically and geometrically corrected data and is a standard NASDA product for ALOS users, though only a relatively small percentage of Level 0 data is processed to Level 1 product.
1.3 Higher-level data product
Products above level 2 are higher-level data products. Higher-level data products are made more sophisticated by processing with digital elevation models. This will be provided by NASDA's EORC one year after ALOS launch.
2. Standard Data Products
Table 5 Standard data products of each sensor
| Level | Definition | Note |
|---|---|---|
| Raw | Demodulated bit stream | Packetized Temporarily archived |
| 0 | Frame synchronization and PN decoding of CADUs and R-S Error Detection and Correction of VCDUs Extracted mission telemetry, orbit and attitude data are stored on separate files. | Compressed (except for PALSAR) Permanently archived Level for distribution to Data Node |
| Level | Definition | Note |
|---|---|---|
| 1A | Uncompressed, reconstructed digital counts appended with radiometric calibration coefficients and geometric correction coefficients (appended but not applied). Individual files for forward, nadir, and backward looking data. |
. |
| 1B1 | Radiometrically calibrated data at Sensor input | . |
| 1B2 | Geometrically corrected data Options G: Systematically Geo-coded (No option: Geo-referenced) |
Map projection Resampling Pixel spacing |
| Level | Definition | Note |
|---|---|---|
| 1A | Uncompressed, reconstructed digital counts appended with radiometric calibration coefficients and geometric correction coefficients (appended but not applied). | Packetized Temporarily archived |
| 1B1 | Radiometrically calibrated data at Sensor input | . |
| 1B2 | Geometrically corrected data Options G: Systematically Geo-coded (No option: Geo-referenced) D: Correction with coarse DEM |
Map projection Resampling Pixel spacing |
| Level | Definition | Note |
|---|---|---|
| 1.0 | Reconstructed, unprocessed signal data appended with radiometric and geometric correction coefficients (appended but not applied). In Polarimetric mode, polarimetric data is separated. |
. |
| 1.1 | Range and azimuth compressed complex data on slant range. Full resolution |
Beam modes: Full resolution mode, Low data rate mode, Polarimetric mode SLC: Single Look Complex Used for interferometry |
| 1.5 | Multi-look processed image projected to map coordinates. Option G: Systematically Geo-coded (No option: Geo-referenced) |
Map projection Resampling Pixel spacing |