The aim of the International SST FRM Radiometer Network (ISFRN) is to develop a community of in situ radiometer builders, operators and data users who will:

  • Promote good practice in the construction and operation of in situ radiometers
  • Agree and establish protocols, formats and standards for quality assurance of data
  • Provide a single access point for the collection and dissemination of radiometer data
  • Support satellite radiometer operators in the long-term validation of satellite products
  • Share knowledge and coordinate activities between Network members
  • Inform the wider community about the Network's activities


Why are shipborne infrared radiometers important?

  • They are used to validate satellite measurements of skin SST, which is what satellite infrared SST measurements measure
  • They provide traceability of measurements to NMI standards (FRM4STS)
  • In the absence of a dual-view satellite sensor, they provide the reference skin SST (fiducial reference measurement)
  • They are needed for the Gap-Bridging between AATSR and SLSTR  
  • As more shipborne radiometers join the ISFRN, the current limited global coverage will be improved


The objectives for Phase 3 of the ships4sst: FRM4SST project are:

  • OBJ-1: Deploy and maintain shipborne thermal infrared (TIR) FRM radiometers and necessary supporting instrumentation to validate satellite SST products.
  • OBJ-2: Maintain Fiducial Reference Measurement (FRM) protocols for satellite SST measurements and uncertainty budgets.
  • OBJ-3: Process, quality control, archive and deliver approved FRM4SST data sets following documented FRM procedures and approve their use for FRM satellite validation.
  • OBJ-4: Validate satellite SST products to FRM standards and publish monthly results.
  • OBJ-5: Promote the FRM4SST outputs and maintain the International SST FRM Radiometer Network (ships4sst).


For instrument operation timeliness and compatibility with the service objectives, the attached spreadsheet is updated with the latest relevant information.