Supported ENVISAT Products |

## Doppler Centroid Parameters

Fields of ENVISAT ASAR_Dop_Cen_ADSR Records

Index | Identifier | Field Type | Field Length | Description | Units
0 | `"zero_doppler_time"` | MJD | 1 | Zero Doppler azimuth time at which estimate applies | MJD
1 | `"attach_flag"` | UChar | 1 | Attachment Flag (always set to zero for this ADSR) | flag
2 | `"slant_range_time"` | Float | 1 | 2-way slant range time origin (t0) | ns
3 | `"dop_coef"` | Float | 5 | Doppler centroid coefficients as a function of slant range time: D0, D1, D2, D3, and D4. where Doppler Centroid = D0 + D1(tSR-t0) + D2(tSR-t0)2 + D3(tSR-t0)3 + D4(tSR-t0)4 | HzHz/sHz/s2Hz/s3Hz/s4
4 | `"dop_conf"` | Float | 1 | Doppler Centroid Confidence Measure. Value between 0 and 1, 0 = poorest confidence, 1= highest confidence. If multiple Doppler Centroid estimates were performed, this value is the lowest confidence value attained. | -
5 | `"dop_thresh_flag"` | UChar | 1 | Doppler Confidence Below Threshold Flag. 0 = confidence above threshold, Doppler Centroid calculated from data. 1 = confidence below threshold, Doppler Centroid calculated from orbit. | flag
6 | `"spare_1"` | Spare | 1 | Spare | -