# Environment Monitoring Instrument
*sensor . products*

UV/VIS grating imaging spectrometer on GF-5 for ozone, NO2, SO2, HCHO and aerosol column monitoring, with four bands from 240 to 790 nm, 1536 channels, daily daylight coverage, and 13 x 48 km resolution.

## Specifications
- **product status**: operational
- **deployment context**: orbital
- **manufacturer**: cnsa
- **sensor**: {"instrument_family":"passive-optical","measurement_principle":"passive","spectral_range_nm":{"min":240,"max":790},"spectral_band_count":1536,"gsd_m":{"native":13},"swath_km":2500,"notes":"WMO OSCAR gives 13 km along-track by 48 km cross-track resolution."}
- **entity type**: sensor
- **last verified date**: 2026-06-16
- **verified by**: agency-doc
- **claim status**: agency-sourced
- **provider**: cnsa
- **attributes**: {"kind":"sensor","product_status":"operational","deployment_context":"orbital","manufacturer":"cnsa","description":"UV/VIS grating imaging spectrometer on GF-5 for ozone, NO2, SO2, HCHO and aerosol column monitoring, with four bands from 240 to 790 nm, 1536 channels, daily daylight coverage, and 13 x 48 km resolution.","sensor":"{\"instrument_family\":\"passive-optical\",\"measurement_principle\":\"passive\",\"spectral_range_nm\":{\"min\":240,\"max\":790},\"spectral_band_count\":1536,\"gsd_m\":{\"native\":13},\"swath_km\":2500,\"notes\":\"WMO OSCAR gives 13 km along-track by 48 km cross-track resolution.\"}"}
- **relevance**: in-scope

## Editorial
Environment Monitoring Instrument (EMI) is an operational UV/VIS grating imaging spectrometer on GF-5 for ozone, nitrogen dioxide, sulfur dioxide, formaldehyde, and aerosol column or profile observations.[^wmo-emi][^emi-no2-2019] Its broad spectral envelope is 240-790 nm across four bands and 1536 channels, while peer-reviewed first-observation work reports 240-710 nm for the GF-5 configuration.[^wmo-emi][^emi-no2-2019]

EMI has a 2500 km swath and 13 km by 48 km ground sampling, with daily daylight global coverage documented for the instrument characteristics.[^wmo-emi] Tropospheric nitrogen dioxide and sulfur dioxide column retrieval is demonstrated on Gaofen-5.[^wmo-emi] The instrument supports wide-swath atmospheric-composition monitoring where UV/VIS trace-gas sensitivity, daily daylight coverage, and moderate spatial sampling are more important than fine-resolution imaging.[^wmo-emi][^emi-no2-2019]

## Compositional position
- gaofen-5 (missions) --[mission_payloads]--> Environment Monitoring Instrument

## Sources
- [wmo-emi] | WMO OSCAR instrument record: EMI | https://space.oscar.wmo.int/instruments/view/emi | tier=agency-doc | accessed=2026-06-16
- [emi-no2-2019] | First observation of tropospheric nitrogen dioxide from the Environmental Trace Gases Monitoring Instrument onboard the GaoFen-5 satellite | https://pmc.ncbi.nlm.nih.gov/articles/PMC7170962/ | tier=peer-reviewed | accessed=2026-06-16
- [ceos-gf5-overview-pdf] | Mission Overview GaoFen-5, CEOS AC-VC-12 presentation | https://ceos.org/document_management/Virtual_Constellations/ACC/Meetings/AC-VC-12/Day%201/5.%20Linagfu%20Chen%20-%20Gaofeng-5%201013.pdf | tier=agency-doc | accessed=2026-06-16 | published=2016-10-13

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