| Accumulated precipitation | 3 - high | Convective precipitation dominant.. Calibration by MW needed. | TIR channels in the 11 micrometers window, and SWIR and the MWIR 3.7 window channel for cloud microphysics. Frequent sampling (GEO) is essential for accumulated precipitation |
| Aerosol column burden | 4 - fair | Cloud sensitive.. Daylight only. | VIS, NIR and SWIR channels with changing solar incidence angles as daylight progresses |
| Aerosol Optical Depth | 4 - fair | Cloud sensitive.. Daylight only. | VIS, NIR and SWIR channels with changing solar incidence angles as daylight progresses |
| Biomass | 4 - fair | Cloud sensitive.. Index only.. Daylight only. | VIS, NIR and SWIR channels. Biomass inferred from NDVI and LAI |
| Cloud cover* | 1 - primary | No specific limitation. | VIS, NIR, SWIR, MWIR and TIR channels |
| Cloud drop effective radius | 3 - high | At cloud top.. Daylight only. | VIS, NIR, SWIR and MWIR channels (for differentiation) |
| Cloud ice effective radius | 3 - high | At cloud top.. Daylight only. | VIS, NIR, SWIR and MWIR channels (for differentiation) |
| Cloud optical depth* | 3 - high | Low-density cloud only.. Daylight only. | VIS, NIR and SWIR channels |
| Cloud top height | 2 - very high | No specific limitation. | TIR channels in window and water vapour band (for emissivity) for temperature; and in CO2 band for atmospheric column above cloud top |
| Cloud top temperature* | 2 - very high | No specific limitation. | TIR channels in window and water vapour band (for emissivity) |
| Cloud type* | 1 - primary | No specific limitation. | VIS, NIR, SWIR, MWIR and TIR channels |
| Downward short-wave irradiance at Earth surface | 3 - high | Cloud sensitive.. Highly indirect. | VIS, NIR and SWIR channels |
| Downward long-wave irradiance at Earth surface | 3 - high | Cloud sensitive.. Highly indirect. | MWIR and TIR channels including water vapour and CO2 bands |
| Earth surface albedo | 3 - high | Cloud sensitive. | VIS channel with changing solar incidence angles as daylight progresses |
| Earth surface short-wave bidirectional reflectance | 3 - high | Cloud sensitive. | VIS, NIR and SWIR channels with changing solar incidence angles as daylight progresses |
| Fire fractional cover | 4 - fair | Cloud sensitive.. Coarse spatial resolution. | VIS, MWIR and TIR channels. Frequent sampling (GEO) enables early detection |
| Fire radiative power | 2 - very high | Cloud sensitive.. Coarse spatial resolution. | MWIR and TIR channels. Frequent sampling (GEO) enables early detection |
| Fire temperature | 2 - very high | Cloud sensitive.. Coarse spatial resolution. | MWIR and TIR channels. Frequent sampling (GEO) enables early detection |
| Land surface temperature | 3 - high | Cloud sensitive. | MWIR and TIR window channels (high sensitivity to high temperature, cloud impact reduction, water vapour correction) |
| Leaf Area Index (LAI) | 2 - very high | Cloud sensitive.. Daylight only. | VIS, NIR and SWIR channels |
| Normalised Difference Vegetation Index (NDVI) | 3 - high | Cloud sensitive. | VIS and NIR channels |
| Photosynthetically Active Radiation (PAR) | 5 - marginal | Cloud sensitive. | VIS channels, range undersampled |
| Precipitation intensity at surface (liquid or solid) | 3 - high | Convective precipitation dominant.. Calibration by MW needed. | TIR channels in the 11 micrometers window, and SWIR and the MWIR 3.7 window channel for cloud microphysics. Frequent sampling (GEO) consistent with precipitation temporal variability |
| Sea surface temperature | 2 - very high | Cloud sensitive. | MWIR and TIR window channels around 3.7 and 11 micrometers (cloud impact reduction, water vapour correction) |
| Short-wave cloud reflectance | 4 - fair | No specific limitation. | VIS, NIR and SWIR channels |
| Snow cover | 2 - very high | Cloud sensitive.. Daylight only. | VIS, NIR and SWIR channels enabling screening snow from clouds. Frequent sampling improves probability of cloud-free views |
| Soil moisture at surface | 4 - fair | Cloud sensitive.. Index only. | VIS, NIR, SWIR, MWIR and TIR channels. Soil moisture inferred from differential brightness and thermal inertia, that are accurately measured by frequent sampling (GEO) |
| Specific humidity | 3 - high | Cloud sensitive.. Coarse vertical resolution.. Middle troposphere only. | TIR channels in the water vapour band around 6.3 micrometers |
| Integrated Water Vapour (IWV)* | 2 - very high | Cloud sensitive. | TIR channels around 6.3 micrometers and in the 11 micrometers split window |
| Upward short-wave irradiance at TOA | 3 - high | Spectral interpolation needed. | VIS, NIR and SWIR channels with changing solar incidence angles as daylight progresses |
| Upward long-wave irradiance at TOA | 4 - fair | Spectral interpolation needed. | MWIR and TIR channels in windows around 3.7 and 11 micrometers, and in water vapour and CO2 bands around 4,3, 6.3 and 15 micrometers |
| Aerosol volcanic ash | 4 - fair | Cloud sensitive.. Daylight only. | VIS, NIR and SWIR channels with changing solar incidence angles as daylight progresses |
| Aerosol volcanic ash Total Column | 1 - primary | Cloud sensitive. | TIR channel(s). Frequent sampling (GEO) enables early detection of ash plumes |
| Wind (horizontal)* | 2 - very high | Cloud or water vapour tracers needed. | VIS channel(s) and TIR channels around 6.3 and 11 micrometers, and 13.3 micrometers for more accurate height assignment. Frequent sampling (GEO) enables inference from cloud or water vapour pathces motion |
| Upward long-wave irradiance at Earth surface | 3 - high | Cloud sensitive.. Highly indirect. | MWIR and TIR channels including water vapour and CO2 bands |
Instrument: GXI