L2P upstream products monitoring

Level 2 Plus (L2P) upstream altimeter data are used as input of the DUACS processing system (see upstream data description).

Data freshness

The following figure presents the monitoring of the aging of the last measurement available at the start time of the DUACS processing. The IGDR/STC (see DUACS processing) products are usually processed with a 24 to 48h delay; OGDR/NRT (see DUACS processing) products are usually processed with few hours delay.

DUACS data freshness

L2P data quality

The following figures present the statistics (mean, number of measurement and standard deviation) at mono-  and multi-mission cross-over locations, before and after calibration processing. Only cross-over with time lag less than 10 days are selected; the metric is computed with a 7 days sampling.

The metric highlights the consistency of the measurements between ascending and descending passes of the reference mission (mono-mission cross-over locations), and between complementary/opportunity and reference mission (multi-mission cross-over locations).

This metric is computed over the Global Ocean. The number of cross over locations depends on the orbit of the satellites and the observed annual cycle is due to the ice coverage close to the pole.

Mean of the mono mission sea surface height differences at cross over locations
Number of mono mission sea surface height cross over locations
Standard deviation of the mono mission sea surface height differences at cross over locations
Mean of the multi mission sea surface height differences at cross over locations
Number of multi mission sea surface height cross over locations
Standard deviation of the multi mission sea surface height differences at cross over locations