# CATS (Cloud-Aerosol Transport System)
*sensor . products*

## Specifications
- **collection**: products
- **manufacturer**: nasa
- **deployment context**: orbital
- **sensor**: {"instrument_family":"lidar","measurement_principle":"active","wavelength_nm":1064,"return_type":"elastic-backscatter"}
- **entity type**: sensor
- **last verified date**: 2026-06-04
- **verified by**: agency-doc
- **claim status**: agency-sourced
- **provider**: nasa
- **attributes**: {"collection":"products","kind":"sensor","manufacturer":"nasa","deployment_context":"orbital","sensor":"{\"instrument_family\":\"lidar\",\"measurement_principle\":\"active\",\"wavelength_nm\":1064,\"return_type\":\"elastic-backscatter\"}"}
- **technology**: lidar

## Editorial
The Cloud-Aerosol Transport System (CATS) is a lidar instrument developed by NASA Goddard Space Flight Center and hosted on the International Space Station (ISS) External Payload Facility.[^cats-gsfc-homepage][^cats-ntrs-2012] CATS uses elastic-backscatter lidar to profile clouds, aerosols, and particulate matter in the atmosphere. The instrument simultaneously transmits at three wavelengths: 1064 nm and 532 nm are cited in agency documentation from cats.gsfc.nasa.gov,[^cats-gsfc-homepage] while eoPortal records the full 1064/532/355 nm three-wavelength configuration.[^cats-iss-eoportal] Laser 2 incorporates an injection-seeded design that enables High Spectral Resolution Lidar (HSRL) capability at 532 nm.[^cats-iss-eoportal] A 60 cm telescope diameter is reported by eoPortal.[^cats-iss-eoportal]

CATS draws heritage from the CALIOP instrument on CALIPSO. The low-inclination ISS orbit enables measurements over tropical and subtropical latitudes, complementing the high-latitude coverage of polar-orbiting instruments.[^cats-ntrs-2012][^cats-iss-eoportal]

## Compositional position
- cats-iss-deployment (missions) --[mission_payloads]--> CATS (Cloud-Aerosol Transport System)

## Sources
- [cats-gsfc-homepage] | CATS Cloud-Aerosol Transport System homepage, NASA GSFC | https://cats.gsfc.nasa.gov/ | tier=agency-doc | accessed=2026-06-04
- [cats-iss-eoportal] | CATS ISS deployment - eoPortal Directory | https://www.eoportal.org/satellite-missions/iss-cats | tier=community | accessed=2026-06-04
- [cats-ntrs-2012] | The Cloud-Aerosol Transport System (CATS): A New Lidar for Aerosol and Cloud Profiling from ISS - NTRS | https://ntrs.nasa.gov/citations/20120011858 | tier=peer-reviewed | accessed=2026-06-04

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Source: https://eo-atlas.org/products/sensor/cats-iss
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