The HDO/H₂O retrieval algorithm is adapted from the algorithm of the operation CO product. It has been updated to account for an extended scientific HDO/H₂O total column data product from short-wave infrared (SWIR) measurements by TROPOMI, including both clear-sky and cloudy scenes. The retrieval is implemented using the existing SICOR algorithm. In contrast to the earlier version, which focused on clear-sky observations using strict cloud filters from the SWIR pre-processor, the updated algorithm uses a scattering-aware retrieval approach to fit total columns of isotopes (H₂O, HDO, H₂¹⁸O, CH₄, CO), surface albedo, spectral offsets, and wavelength-dependent reflectance. The retrieval window is optimized to capture strong HDO absorption lines, distinct from H₂O lines.
The hydrological cycle is a critical component in understanding climate change. Water vapor, as the strongest natural greenhouse gas, plays a key role in atmospheric feedback mechanisms and processes such as cloud formation. Accurate measurements of atmospheric humidity and its isotopic composition are essential for improving the projections of atmospheric general circulation models (GCMs), which are used to simulate climate-related processes.
The SRON HDO processor is developed and maintained by SRON.
Available resources:
| Algorithm Theoretical Basis Document (ATBD) |
| Product User Manual (PUM) |
| Validation Report (DOI 10.5194/amt-13-85-2020) |
| Validation Report (DOI 10.5194/amt-15-2251-2022) |
The processing of the HDO products is performed by SRON locally and not on the S5P-PAL platform. Output products are send directly to the S5P-PAL data portal for publication. The dataset currently covers the period 2018-2022. More recent data is expected to arrive later this year.
The dataset does not provide a full timeline and products for several orbits are known to be missing. Information about known acquisition gaps in the data can be found on the Mission Status webpage of Sentinel-5P.
Available product files can be selected and downloaded using the SpatioTemporal Asset Catalog (STAC) browser interface.
This browser interface does not currently support the more advanced search queries made possible by the STAC API. For that you will need to programmatically query the S5P-PAL STAC endpoint.
Questions regarding this service can be send to the ESA EO Support Helpdesk.
This service is provided as part of the Sentinel-5P Product Algorithm Laboratory (S5P-PAL) and contains modified Copernicus Sentinel data processed by S[&]T.
