There are different data product types depending on delivery time to users:
- Near Real-Time (NRT): delivered less than 3 hours after data acquisition and mainly used for marine meteorology and ocean-atmosphere gas transfer studies (and possibly for operational oceanography depending on orbit accuracy).
- Slow-Time Critical (STC): delivered within 48 hours after data acquisition, due mainly to the consolidation of some data (e.g. preliminary restituted orbit data) and the data are mainly used for geophysical studies and operational oceanography.
- Non-Time Critical (NTC): typically delivered within 1 month after data acquisition. This additional delay allows consolidation of some data (e.g. precise orbit data) and the data are mainly used for geophysical studies and operational oceanography.
Figure 1: SRAL/MWR Level-2 Product Timeliness (Credit: ESA)
The selection of a product type in terms of delivery time (NRT, STC and NTC) is a trade-off between real-time needs and the final accuracy needed. Some Level-2 parameters depend on consolidating data such as orbit, platform or wet and dry tropospheric corrections.