An interactive website to view and contribute to Sentinel-3 and Sentinel-6-MF OLTC for inland waters measurement

The website, developed by Noveltis for ESA, offers the possibility to display the Open-Loop Tracking Command (OLTC) tables for inland water targets currently onboard ESA Sentinel-3 SRAL altimeters, as well as the Copernicus Sentinel-6-MF Poseidon-4 altimeter. The addition of Sentinel-6-MF is one of the new features of this latest release and brings the total number of hydrological targets displayed to ~180,000 worldwide.

An interactive map allows visitors to navigate and display elevation commands defined over lakes, reservoirs and rivers overflown by the three nadir altimeters.

In addition to the improvement of the general layout of the website, several visualization tools have been added to enhance the OLTC website experience: choice of map layout, display of satellite ground tracks, filter by target type...

Screenshot of the OLTC website new display
 

Outside of these hydrological targets, the elevation command defined in the OLTC table is set to the mean continental surface elevation, so that the altimeter constantly tracks the Earth’s surface.

Call for hydrology users’ contributions

Users wishing to further contribute to OLTC contents may sign up and have access to additional functionalities: once logged in, they have the possibility to submit modifications of existing elevations as well as requesting new targets that may not yet be defined in the onboard OLTC tables.

For example, adding a target over a river or a lake, in order to enhance the OLTC contents and make sure that the altimeter will acquire quality echoes over the defined targets. Requests may be submitted directly using the "Contribute" tool on the right panel or by sending a list of targets to the OLTC database management committee.

We encourage scientists and Sentinel users to visit the website and contact us via the Contact form for further questions.

Background information on the Open-Loop mode

The Open-Loop Tracking Command (OLTC) represents a major evolution of the altimeter tracking function that was first developed for Jason-2 and SARAL/Altika missions as probative mode (called Diode/DEM mode).Taking into account this experience, this tracking mode's efficiency has been proven and it is now stated as operational mode for Jason-3, Sentinel-3 and Sentinel-6-Michael-Freilich missions.

On Sentinel-3, areas of interest define where SRAL is operated in OLTC mode. Outside these areas, SRAL altimeters operate in Close-Loop mode (i.e. autonomous tracking mode), with no a priori elevation information used to set the echo reception window.

On Sentinel-6-MF, Poseidon-4 nominally operates in OLTC mode over all oceans and continental surfaces.

Due to the execution of Sentinel-3B In-Plane Manoeuvre, Data products degradation is expected for sensing time from 20/04/2023T09:50:38 to 20/04/2023T10:00:44.

We would like inform you that the 8th S3VT meeting has been scheduled to take place on 5-7 December 2023, in Darmstadt, Germany.

The 8th S3VT will be hosted by EUMETSAT and co-chaired with ESA. More information on the call for participation and abstract submission are available from https://www.s3vt.org.

This will be the perfect meeting to present your latest results on the recent level-2 Sentinel -3 Land Altimetry Thematic Products (TPs).

The Sentinel -3 Land Altimetry Thematic Products are currently available as pilot data products, but the full mission reprocessing is ongoing. The release of the level-2 TPs will cover from the beginning of the mission up to date, and the new processing baseline will be then transferred in nominal operations to maintain a uniform processing baseline.

Check out more information on the new thematic products at the following resources:

• Sentinel-3 SRAL/MWR User Handbook

• Sentinel-3 level-2 Product Data Format Specifications

• Product Notice on Sentinel-3 STM LAND Processing Baseline evolutions

• Sentinel-3 Land Altimetry Thematic Products (Baseline Collection 005) availability notice

• Sentinel-3 Land Altimetry Thematic Products (Baseline Collection 005) replaces present product types

Due to Copernicus Sentinel-3B Ground Segment anomaly, S3B Products publication on Data Hub is delayed starting from 11/04/2023T19:00 UTC.

The Copernicus Sentinel-3 Altimetry Land Thematic Products (TP) with Baseline Collection 005 (BC005) are currently under reprocessing to generate improved and tailored level-2 data for both Sentinel-3A and Sentinel-3B missions. The release of TP reprocessed data products is planned in few months from now, and all the relevant information is available from a dedicated web page.

The release of the Sentinel-3 Altimetry Land Thematic Products BC005 will cover the full mission data set from the beginning of the mission, substituting the current Sentinel-3 STM Land level-2 products with BC004.

Due to predicted outage for Copernicus Sentinel-3A In-Plane Manoeuvre, SLSTR products degradation is expected for sensing time from 05/04/2023T06:55:39 to 05/04/2023T07:05:44 UTC.

Due to predicted outage for Copernicus Sentinel-3B Out-of-Plane Manoeuvre, data will be degraded on hereafter products:

• Copernicus Sentinel-3BSLSTR: products degradation is expected for sensing time from 05/04/2023T09:25:32 to 05/04/2023T10:00:38

• Copernicus Sentinel-3B SRAL: products degradation is expected for sensing time from 05/04/2023T09:25:32 to 05/04/2023T10:00:38

Due to Copernicus Sentinel-3B Moon calibration, data will be degraded on hereafter products:

• Copernicus Sentinel-3B SLSTR: products degradation is expected for sensing time from 06/04/2023T15:41:09 to 06/04/2023T16:31:39
• Copernicus Sentinel-3B OLCI: products degradation is expected for sensing time from 06/04/2023T16:25:34 to 06/04/2023T16:31:39
• Copernicus Sentinel-3B SRAL: products degradation is expected for sensing time from 06/04/2023T15:42:09 to 06/04/2023T16:12:46

Following the previous news, we are pleased to inform that the Copernicus Sentinel-3 Altimetry Land Thematic Products (TP) with Baseline Collection 005 (BC005) are currently under reprocessing to generate improved and tailored level-2 data for both Sentinel-3A and Sentinel-3B. The release of the level-2 TP’s will cover from the beginning of the mission up to date, and the new processing baseline will be then transferred in nominal operations to maintain a uniform processing baseline.

The reprocessing activities is performed by Telespazio (IT) in coordination with the Sentinel-3 Land Altimetry Mission Performance Cluster led by CLS (FR) and it is planned to complete by Q3 2023.

It is recalled that the data availability plan will be routinely updated on a dedicated page, providing details on the periods published, as well as indicators on the proceedings of the reprocessing with the forthcoming periods soon to be published.

Users are invited to start making use of the gradually building long-term time-series of Collection-005 products!

Due to Copernicus Sentinel-3B In-Plane Manoeuvre, SLSTR Products degradation is expected for sensing time from 13/03/2023T17:59:46 to 13/03/2023T18:10:50UTC.

Due to Copernicus Sentinel-3B In-Plane Manoeuvre, data will be degraded on hereafter products:

• Copernicus Sentinel-3B SLSTR: products degradation is expected for sensing time from 13/03/2023T15:53:15 to 13/03/2023T16:03:09 UTC

• Copernicus Sentinel-3B OLCI: products degradation is expected for sensing time from 13/03/2023T15:53:15 to 13/03/2023T15:53:57 UTC

Due to predicted outage for Copernicus Sentinel-3B In-Plane Manoeuvre, SLSTR Products degradation is expected for sensing time from 22/03/2023T09:00:39 to 22/03/2023T09:10:43UTC.

• Copernicus Sentinel-3A SLSTR: products degradation is expected for sensing time from 07/03/2023T22:45:54 to 07/03/2023T23:36:24                  
• Copernicus Sentinel-3A OLCI: products degradation is expected for sensing time from 07/03/2023T23:30:00 to 07/03/2023T23:36:24    
• Copernicus Sentinel-3A SRAL: products degradation is expected for sensing time from 07/03/2023T22:46:54  to 07/03/2023T23:16:36

Due to predicted outage for Copernicus Sentinel-3A Out-of-Plane Manoeuvre, SLSTR and SRAL products degradation is expected for sensing time from 01/03/2023T08:31:51 to 01/03/2023T09:07:04 UTC.

Due to Copernicus Sentinel-3B SLSTR instrument anomaly and related recovery operations, products unavailability/degradation is expected as follows:

• SLSTR products degradation is expected for sensing time from 24/02/2023T23:40:36 to 25/02/2023T08:49:13
• SLSTR products are unavailable for data with sensing time from 25/02/2023T08:49:13 to 25/02/2023T12:02:20
• SLSTR products degradation is expected for sensing time from 25/02/2023T12:02:20 to 25/02/2023T15:17:19
• SLSTR products are unavailable for data with sensing time from 25/02/2023T15:17:19 to 25/02/2023T16:58:43
• SLSTR products degradation is expected for sensing time from 25/02/2023T16:58:43 to 26/02/2023T23:11:33

We are pleased to inform that the Copernicus Sentinel-3 Altimetry Land Thematic Products (TP) with Baseline Collection 005 (BC005) are currently under reprocessing to generate improved and tailored level-2 data for both Sentinel-3A and Sentinel-3B. The release of the level-2 TP’s will cover from the beginning of the mission up to date, and the new processing baseline will be then transferred in nominal operations to maintain a uniform processing baseline.

The reprocessing activities is performed by Telespazio (IT) in coordination with the Sentinel-3 Land Altimetry Mission Performance Cluster led by CLS (FR) and it is planned to complete by Q3 2023.

It is recalled that the data availability plan will be routinely updated on a dedicated page, providing details on the periods published, as well as indicators on the proceedings of the reprocessing with the forthcoming periods soon to be published.

Users are invited to start making use of the gradually building long-term time-series of Collection-005 products!