1 February 2021 - WP70: Preparation of MW/TIR Experiments

Since July 2020 the Danish Technical University (DTU) has been working on the refurbishment of a passive microwave (PMW) radiometer in preparation for a short land-based demonstration of simultaneous deployment of thermal infrared and microwave radiometers. In January this year DMI conducted the demonstration on a small bridge in Copenhagen (see image), with one ISAR deployed alongside two microwave radiometers for C-band and X-band measurements. Initial results show good agreement between the IR and PMW observed SSTs, as seen in the graph shown below.

Figure 1: The radiometers supported by scaffolding as part of the demonstration over a brdige in Copenhagen.

Figure 2: The temperature comparison between ISAR and EMIRAD (the two microwave radiometers).


31 October 2020 - The ISFRN workshop took place online on the 17 - 18th September with talks on the results and progress of in situ radiometer deployments, calibration and validation and how the data is used in practise. The project would like to thank and acknowledge all the presenters for their fantastic talks over the two days of the workshop. Recordings are now online.


1 September 2020 - WP60: Plan a CEOS International TIR Inter-comparison Exercise

Our WP 60 team have been busy reviewing the lessons learnt from the 2016 inter-comparison exercise, to help plan the next international TIR radiometer inter-comparison. We are also in discussion with colleagues regarding the set up of a 2021/2022 laboratory inter-comparison. Our lead scientist, Werenfrid Wimmer, will be presenting plans for the future inter-comparison exercise at our ISFRN workshop on the 18th September.


3 August 2020 - WP80: Study for a next generation radiometer

Last month, the team began a package of work set to define the next generation of ship radiometers, to provide continued high-quality validation of satellite measurements now and in the future. We are currently assessing the design of current instruments and working through the needs of the SST community, so that a clear specification of a new and improved radiometer can be produced! See our Tasks page for more information.


9 July 2020 - The team is excited to begin work on several new work packages this month. They include planning for an international CEOS thermal infrared (TIR) radiometer inter-comparison, undertaking a study for a future generation radiometer and conducting a pilot study to compare measurements of TIR and microwave SST in cold waters. 


2 June 2020 - Our science leader, Werenfrid Wimmer, presented the results of his SST validation work to the GHRSST community today.  The results of the validation of SLSTR data using ships4sst data indicate that SLSTR is performing very well with virtually no mean difference between the SLSTR and FRM data at night and only a small difference during the day. 


5 May 2020 - Details for the next ISFRN workshop are now online! This workshop is now completley virtual, please join us for the latest information on shipborne radiometers and the verification and uses of SST skin data.


27 April 2020 - Deployments for ISAR (Uos) and SISTeR are currently on hold whilst ships remain in port during the Covid-19 pandemic. It is currently unknown when deployments will resume but our operators are keeing in close contact with their respective ships of opportunity to keep up-to-date with the latest deployment schedules.


16 March 2020 - The Felyx processor version has been updated recently to v4.0/r1i1. This has resulted in better validation results; a comparison can be seen in the figures shown below.


17 February 2020 - Our Science Lead, Werenfrid Wimmer, presented at the Oceans Science Meeting in San Diego, USA today. He showed examples of the ships4sst data and demonstrated its use with the newest SLSTR validation results from the ships4sst network regions; showing that SLSTR performs at least as well as its predecessor AATSR. Results of the SLSTR A and B units during the Sentinel-3 tandem phase in 2018 were also shown by using triple collocations on the ships4sst FRM data and the SLSTR units on Sentinel 3 A and B. More information can be found on the poster here.


5 September 2019 - Does it matter where you place your shipborne radiometer when you do FRM observations of SST? Yes it does!  

Measurements made by a thermal camera mounted on a drone by the DMI group during a cruise revealed that it does indeed make a large difference whether the radiometer measures on disturbed water or waters not affected by the ships wake. The figures below show the radiometric temperature fields as observed from two locations onboard the ship. Figure 1 is taken from the front of the ship where the DMI ISAR is mounted and shows a small spatial variation within the field of view.

Figure 1: thermal readings of the water taken by the drone at the front of the ship 

Figure 2 is taken from the starboard side of the ship and shows how the observed temperature varies significantly through the field of view. The variation is mainly due to different emissivities for the foam and calm waters. 

Figure 2: thermal readings of the water taken by the drone at starboard

Such investigations are very helpful to ensure the quality and traceability of the SST FRM observations taken within the FRM4SST project, which are used to validate satellite SST products to FRM standards. 


31 July 2019 -  Our DMI experts have been using drone technology to observe the spatial SST field around the M/S Norrona. For more information follow our DMI lead scientist at  


30 June 2019 - Our shipborne radiometers have continued on their deployments on the Pont Aven, M/S Norrona and the Queen Mary 2. Visit our deployments page for links to the current location of the instruments. A photograph of the SISTeR instrument mounted on the Queen Mary 2 is shown below. 


1 May 2019 - The next stage of the ships4sst project, the ESA-funded FRM4SST contract beings today,with the aim of continuing the ISAR and SISTeR deployments, validating satellite SST data from SLSTR and other instruments and furthering the ISFRN development. 


31 March 2019 - Today marks the end of the first Ships4sst contract and we look forward to the next phase of the ESA-funded contract starting in May. For now, here is a world map showing the SST radiometer data gathered by our colleagues and currently stored in our archives (accessible via this website). Further information can be found in our Final Report

Figure caption: The ships4sst data archive L2R files plotted as SST on the world map


28 February 2019 - The ISFRN workshop finished today with a number of successful presentations from prominent scientists within the SST radiometer community and a group discussion in which strategies for taking the ISFRN forward were discussed. Presentations can be found on the documents page and more information on the workshop can be found on the workshop page. 


20 September 2018 - Details for the upcoming ISFRN Workshop have been posted online at


5 April 2018 - A new contract, "Copernicus SLSTR SST Validation using Fiducial Reference Measurements" (aka "ships4sst") has kicked off today. This is an ESA contract with the University of Southampton, RAL Space, DMI and Space ConneXions, which is designed to continue the skin SST measurements from ISAR and SISTeR that were previously funded by BEIS and its predecessor departments since 2004. The new project falls under the EU Copernicus programme and as intended to support the tying together, to a common internationally recognised reference standard, of climate quality SST measurements from AATSR and SLSTR so that the long-term SST time series started by the ATSR sensors may be continued by SLSTR. The ships4sst contract will continue until 31 March 2019, when the UK's role in the Copernicus programme following Brexit is expected to be clarified.