Configuration Information

Data processing has been organized into processing runs, called Releases, with each Release starting at the beginning of the mission and ending when the data is reprocessed due to algorithm updates and new products being made available. Epochs reflect changes in the operating parameters of the mission, such as the CPR configuration.

Epochs

• Epoch 00: During the initial phase of the mission it was unknown that the CPR was pointing off-nadir 1.7021 degrees in the forward (along-track) direction and 0.1314 degress to the right (across-track).

• Epoch 01: The pointing error was corrected and the spacecraft was oriented so that the CPR pointed to nadir.

• Epoch 02: Increased specular reflection due to the nadir-pointing instrument caused an increase in ground clutter, so the spacecraft orientation was changed again so that the CPR pointed 0.16 degrees in the forward (along-track) direction.

• Epoch 03: Epoch 02 ended when a battery anomaly forced the CPR offline. It was brought back into operations with a slightly reduced pulse rate that decreases the radar sensitivity by approximately 0.25 dB. Epoch 03 tags the modified operating parameters.

• Epoch 04: Marks the beginning of a period where the CPR pulse rate will be periodically reduced, or increased, to manage the power draw on the battery (due to the reduced power margin as the battery ages). The increased or reduced pulsing with induce a slight change in sensitivity. The number of pulses can be found in the 1B-CPR field RayStatus_pulsesTx. The pulse rate will likely continue to be adjusted, seasonally, for the duration of the mission.

Releases

Release 4 (R04)

This release incorporates several improvements for the data products primarily driven by the development of a surface clutter reduction scheme in 1B-CPR. This affects all products by improving cloud detection near the Earth's surface. In addition, the profile overlap at the beginning and end of each granule has been removed. Granules now start with the first profile on or after the equator on a descending pass and end with the last profile before the equator on the next descending pass. Release 4 also includes the first release of the 2B-GEOPROF-LIDAR product.

Release 3 (R03)

With the implementation of the off-nadir geolocation correction, the entire mission from 2 June to the present time can be reprocessed (R03 for the level 1B and 2B products). The two main events causing the epoch numbers to increment in the filenames remain the maneuvers to point to nadir on 7 July and to point slightly off-nadir on 15 August.