# Surface Waves Investigation and Monitoring instrument (SWIM)
*component . products*

Ku-band rotating multi-beam radar altimeter flown on CFOSAT for wave spectra and significant wave height.

## Specifications
- **product status**: operational
- **deployment context**: orbital
- **manufacturer**: cnes
- **entity type**: component
- **last verified date**: 2026-06-16
- **verified by**: agency-doc
- **claim status**: agency-sourced
- **provider**: cnes
- **attributes**: {"kind":"component","product_status":"operational","deployment_context":"orbital","manufacturer":"cnes","description":"Ku-band rotating multi-beam radar altimeter flown on CFOSAT for wave spectra and significant wave height."}
- **relevance**: in-scope

## Editorial
Surface Waves Investigation and Monitoring (SWIM) is the rotating multi-beam Ku-band radar on CFOSAT for significant wave height and directional ocean-wave spectra.[^wmo-swim-instrument][^aviso-cfosat-swim] It operates at 13.575 GHz with 320 MHz bandwidth and on-board digital range compression for the backscattered signal.[^wmo-swim-instrument][^aviso-cfosat-swim] Six beams cover nadir through 10 degrees of incidence, at 0, 2.4, 4, 6, 8 and 10 degrees.[^wmo-swim-instrument] The rotating antenna provides a 180 km swath and an approximately 18 km by 18 km footprint at 500 km altitude.[^wmo-swim-instrument][^aviso-cfosat-swim] The instrument rotation rate is 5.7 rpm, with a 5.6 rpm alternate for the same scan.[^wmo-swim-instrument][^aviso-cfosat-swim] SWIM demonstrates radar altimetry on CFOSAT, and its low-incidence rotating beams are used for wave-spectra measurement in addition to altimetric ranging.[^wmo-swim-instrument][^aviso-cfosat-swim] SWIM is active on CFOSAT, with end of life at least 2026 and follow-on use on HY-2L/CFOSAT-FO from 2030 to 2038.[^wmo-cfosat-satellite][^wmo-swim-instrument]

## Compositional position
- cfosat (missions) --[mission_payloads]--> Surface Waves Investigation and Monitoring instrument (SWIM)

## Sources
- [wmo-cfosat-satellite] | WMO OSCAR satellite record: CFOSAT | https://space.oscar.wmo.int/satellites/view/cfosat | tier=community | accessed=2026-06-16
- [wmo-swim-instrument] | WMO OSCAR instrument record: SWIM | https://space.oscar.wmo.int/instruments/view/swim | tier=community | accessed=2026-06-16
- [aviso-cfosat-swim] | AVISO+ CFOSAT SWIM instrument page | https://www.aviso.altimetry.fr/en/missions/current-missions/cfosat/instruments/swim.html | tier=agency-doc | accessed=2026-06-16
- [swim-tgrs-2021] | New Observations From the SWIM Radar On-Board CFOSAT | https://doi.org/10.1109/TGRS.2020.2994372 | tier=peer-reviewed | accessed=2026-06-16

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Source: https://eo-atlas.org/products/component/cfosat-swim
Maintainer: SpectraWorks B.V. (CC-BY 4.0)