The RVL surface radial velocity component is a ground range gridded difference between the measured Level-2 Doppler grid and the Level-1 calculated geometrical Doppler. The RVL component provides continuity of the ASAR Doppler grid. The RVL estimates are produced on a ground-range grid.
The Level-2 Doppler is computed on a grid similar to the OWI component grid and provides an estimate of the Doppler frequency and the Doppler spectral width. For TOPS, one grid is provided by swath (additional dimension in the NetCDF). The uncertainties of the estimates are also provided for both the Doppler and radial velocity.The Doppler frequency and the Doppler spectral width are estimated based on fitting the azimuth spectral profile of the data to the antenna model taking into account additive noise, aliasing, and side band effects. The Doppler frequency provided in the product is the pure Doppler frequency estimated from the SLC data without correcting for geometry and mispointing errors.
| RVL Characteristics | |
| Coordinate System | Ground Range |
| Incidence angle [*] | S1 22.3 S2 25.6 S3 31.2 S4 36.4 S5 41.0 S6 43.8 IW1 32.9 IW2 38.4 IW3 43.1 EW1 23.7 EW2 30.9 EW3 36.2 EW4 40.9 EW5 44.5 WV1 23 WV2 36.5 |
| Radial Surface Velocity Spatial Resolution [km x km] |
SM: 1x1 Product splits 170km x 80km SM image into 170 * 80 images of 1km x 1km for RVL estimate. IW: 1x1 Product split 170kmx~80km IW swath image into 170x~80 images of 1kmx1km x 3 (number of swath) for RVL estimate EW: 1x1 Product split 400km*~80km IW swath image into 400*~80 images of 1kmx1km x 5 (number of swath) for RVL estimate WV:20x20 |
| Radial Surface Velocity Grid Dimension [azimuth cell x ground range cell] |
SM: 170x80 IW: 170x80x3 EW: 400x80x5 WV: 1x1 |
| Radial Surface Velocity [m/s] | SM:∈{-10,+10}, RMS ∈{0.29, 0.37} IW, EW:∈{-10,+10}, RMS {0.30, 0.38} WV1:∈{-10,+10}, RMS ≈ 0.30 WV1:∈{-10,+10}, RMS ≈ 0.34 |
| Doppler Frequecy[Hz] | SM, IW, EW: ∈{0,60},RMS ∈{2,5} WV1: ∈{0,60},RMS ∈{2,5} WV2: ∈{0,40},RMS ∈{2,5} |
| Doppler Spectral Width [Hz] | SM, IW, EW: ∈{0,200} WV1: ∈{0,200} WV2: ∈{0,100} |