# Microwave Radiometer (MWR)
*sensor . products*

Microwave radiometer flown on Sentinel-3.

## Specifications
- **manufacturer**: thales-alenia-space
- **product status**: operational
- **deployment context**: orbital
- **sensor**: {"instrument_family":"radiometer","measurement_principle":"passive","frequency_bands_ghz":[23.8,36.5],"scan_type":"static","notes":"Sentinel-3 nadir-viewing microwave radiometer."}
- **entity type**: sensor
- **last verified date**: 2026-06-16
- **verified by**: agency-doc
- **claim status**: agency-sourced
- **provider**: thales-alenia-space
- **attributes**: {"kind":"sensor","manufacturer":"thales-alenia-space","product_status":"operational","deployment_context":"orbital","description":"Microwave radiometer flown on Sentinel-3.","sensor":"{\"instrument_family\":\"radiometer\",\"measurement_principle\":\"passive\",\"frequency_bands_ghz\":[23.8,36.5],\"scan_type\":\"static\",\"notes\":\"Sentinel-3 nadir-viewing microwave radiometer.\"}"}
- **relevance**: in-scope

## Editorial
MWR is the Sentinel-3 nadir-viewing passive microwave radiometer that supports SRAL radar-altimeter measurements by correcting for atmospheric water vapour.[^wmo-mwr-sentinel3] It has two channels, 23.8 and 36.5 GHz, aligned with water-vapour and cloud-liquid-water sensitivity in the altimetry correction workflow.[^wmo-mwr-sentinel3][^nasa-earthdata-s3-mwr] The instrument performs passive microwave radiometry, demonstrated on Sentinel-3A.[^wmo-mwr-sentinel3] EUMETSAT uses Sentinel-3 altimetry Level-2 processing with microwave-radiometer correction information for sea-surface-height and related ocean-altimetry products.[^eumetsat-s3-altimetry-l2]

## Compositional position
- sentinel-3b (missions) --[mission_payloads]--> Microwave Radiometer (MWR)

## Sources
- [wmo-mwr-sentinel3] | WMO OSCAR instrument record: MWR (Sentinel-3) | https://space.oscar.wmo.int/instruments/view/mwr_sentinel_3 | tier=agency-doc | accessed=2026-06-16
- [nasa-earthdata-s3-mwr] | NASA Earthdata instrument page: Sentinel-3 MWR | https://www.earthdata.nasa.gov/data/instruments/sentinel-3-mwr | tier=agency-doc | accessed=2026-06-16
- [eumetsat-s3-altimetry-l2] | EUMETSAT Sentinel-3 altimetry level 2 data guide | https://user.eumetsat.int/resources/user-guides/sentinel-3-altimetry-level-2-data-guide | tier=agency-doc | accessed=2026-06-16

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Source: https://eo-atlas.org/products/sensor/mwr
Maintainer: SpectraWorks B.V. (CC-BY 4.0)