N: 66.15 S: -66.15 E: 180 W: -180
Description
Provides L1A high resolution (HR) short time critical (STC; 36-hour latency) altimetry intermediate outputs from the Poseidon-4 SAR altimeter on the Sentinel-6A Michael Freilich spacecraft, which are geo-located bursts of Ku-band echoes (at ~140 Hz) with all instrument calibrations applied and full rate complex waveforms for delay/Doppler or HR processing. The S6A STC product is analogous to the Jason-3 IGDR product.
Product Summary
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Variables
The table below lists the variables contained within a single granule for this dataset. Variables often contain observed or derived geophysical measurements collected from a variety of sources, including remote sensing instruments on satellite and airborne platforms, field campaigns, in situ measurements, and model outputs. The terms variable, parameter, scientific data set, layer, and band have been used across NASA’s Earth science disciplines; however, variable is the designated nomenclature in NASA’s Common Metadata Repository (CMR). Variable metadata attributes such as Name, Description, Units, Data Type, Fill Value, Valid Range, and Scale Factor allow users to efficiently process and analyze the data. The full range of attributes may not be applicable to all variables. Additional information on variable attributes is typically available in the data, user guide, and/or other product documentation.
For questions on a specific variable, please use the Earthdata Forum.
| Name Sort descending | Description | Units | Data Type | Fill Value | Valid Range | Scale Factor | Offset |
|---|---|---|---|---|---|---|---|
| /global/ku/range_cor_external_group_delay | The absolute 1-way group delay contribution for parts outside the calibration loop | m | int | -2147483647 | N/A | 0.0001 | N/A |
| /global/ku/range_oversampling_factor | The instrument samples the waveforms with a 395 MHz clock, providing a nominal_sampling = c / 395e6 / 2 = ~0.379m (with c=speed of light). In addition, the ground processor can apply an oversampling factor, providing a waveform_sampling = nominal_sampling / range_oversampling_factor. Note that the altimeter range resolution is fixed and given by the chirp bandwidth of 320 MHz: c / 320e6 / 2 = ~0.468m | 1 | short | -32767 | N/A | 1 | N/A |
| /global/ku/residual_fixed_digital_gain_raw | The digital processor on board is calibrated during CAL1. This variable is a placeholder for (potential) residual gains to be applied to the SAR RAW waveform. | dB | int | -2147483647 | N/A | 1.0E-6 | N/A |
| /global/ku/residual_fixed_digital_gain_rmc | The digital processor on board is calibrated during CAL1. This variable is a placeholder for (potential) residual gains to be applied to the SAR RMC waveform. | dB | int | -2147483647 | N/A | 1.0E-6 | N/A |
| pulses | Counter to index the pulses within a burst (from 0 to 63) | N/A | byte | N/A | N/A | 1 | N/A |
| samples | Counter to index the I and Q samples within a pulse (from 0 to 255) | N/A | short | N/A | N/A | 1 | N/A |
| space_3d | Counter to index the cartesean coordinates (from 1 to 3) | N/A | byte | N/A | N/A | 1 | N/A |