SWOT Level-2 HR Lake Single Pass - Observed

The SWOT Level-2 HR Lake Single Pass - Observed dataset provides vectorized lake data - including water surface elevation, water surface area, and derived storage change - from the High Resolution data stream of the SWOT KaRIn instrument, along with appropriate uncertainties and flags.

This dataset is observation-oriented, meaning that it contains one record for each observed lake identified in the SWOT Prior Lake Database (PLD) - greater than 1ha- that is covered by the granule. Note that one observed lake may correspond to several PLD lakes. Two complementary datasets are also available:

- SWOT Level-2 HR Lake Single Pass – Prior

- SWOT Level-2 HR Lake Single Pass - Unassigned

The first is PLD-oriented, the second is observation-oriented and contains the unassigned features - meaning not identified in the PLD.

The dataset was generated by the SWOT Mission Center but may be simulated using the SWOT Hydrology Toolbox Open Source tools.

The SWOT Level-2 HR Lake Single Pass - Observed dataset is provided in full-swath pass granules covering individual continents. Note: a granule covers a swath that is approximately 128 km wide in cross track, although SWOT performance requirements are only applicable from 10–60 km from nadir on each side; observations may be missing, degraded, and/or flagged over the central 20 km of the swath. A pass is a half revolution of the Earth by the satellite from pole to pole.

Major SWOT product versions are called “baseline”. Currently, on our platform, you can download and manipulate products from both baseline C and D. Baseline C covers the period from March 28, 2023 to May 05, 2025. After this date, only baseline D products are available. A global reprocessing is on-going to produce baseline D products for the full SWOT activity period. Baseline D products are progressively made available so you might find some gap in baseline D until the end of the reprocessing.

General, global and up-to-date information on SWOT products can be find in the SWOT User Handbook. For a focus on how to distinguish between Baseline C and D products along with most significant changes in products, please refer to the Version D Release Note and the Major Changes from Version C to D slides.

Finally, you will find below links to the Product Description Document (PDD) and Algorithm Theoretical Basis Document (ATBD) for a thorough look at the product:
- Product Description Document
- Algorithm Theoretical Basis Document

Explore a gallery of open-source tutorials and tools intended to ease the utilization of SWOT data products here.

Please cite the data as follows :
- Baseline D: https://doi.org/10.5067/SWOT-LAKESP-D
- Baseline C: https://doi.org/10.5067/SWOT-LAKESP-2.0