Advanced Geostationary Radiation Imager (AGRI)


A multiple channel radiation imager, one of the primary instruments onboard FY-4. Technically featured by precisely designed two-mirror structure, capable of accurate and flexible sensing in two dimensions, and minute-level fast sector scanning. Frequent earth imaging over 14 bands with off-axis three reflections of primary optic system. On-board black body available for IR calibrations at very short time intervals.

Satellite FY-4A FY-4B 
Weight 306kg
Number of channels FY-4A: 14, FY-4B: 15
Spatial resolution 0.5~1 km (VIS/near IR), 2~4 km (IR)
Time for full-disc scanning 15 min
Time for sector scanning 1min (1000km × 1000km)
Sensitivity S/N>3 @ 1% (reflection bands)
NE∆T: 0.2K @ 300K (IR bands)

Characteristics (FY-4A)

Channel Type Central wavelength Band SNR or NEΔT @ specified input Spatial resolution Main purpose
1 Visible & Near-Infrared 0.47µm 0.45~0.49µm S/N≥90 @ ρ=100% 1km Aerosol
2 0.65µm 0.55~0.75µm S/N≥200 @ ρ=100% 0.5~1km Fog, cloud
3 0.825µm 0.75~0.90µm S/N≥200 @ ρ=100% 1km Vegetation
4 Short-wave Infrared 1.375µm 1.36~1.39µm S/N≥90 @ ρ=100% 2km Cirrus
5 1.61µm 1.58~1.64µm S/N≥200 @ ρ=100% 2km Cloud, snow
6 2.25µm 2.1~2.35µm S/N≥200 @ ρ=100% 2~4km Cirrus, aerosol
7 Mid-wave Infrared 3.75µm 3.5~4.0µm (high) NEΔT≤0.7K @ 300K 2km Fire
8 3.75µm 3.5~4.0µm (low) NEΔT≤0.2K @ 300K 4km Land surface
9 Water vapor 6.25µm 5.8~6.7µm NEΔT≤0.3K @ 260K 4km High level water vapor
10 7.1µm 6.9~7.3µm NEΔT≤0.3K @ 260K 4km Middle level water vapor
11 Long-wave Infrared 8.5µm 8.0~9.0µm NEΔT≤0.2K @ 300K 4km Water vapor, cloud
12 10.7µm 10.3~11.3µm NEΔT≤0.2K @ 300K 4km Surface temperature
13 12.0µm 11.5~12.5µm NEΔT≤0.2K @ 300K 4km Surface temperature
14 13.5µm 13.2~13.8µm NEΔT≤0.5K @ 300K 4km Cloud thickness

AGRI transmittance over wavelength

AGRI scan range (105°E)

Data and Products

Satellite Instrument Datasets
FY-4B AGRI L1 dataL2L3 product
FY-4A AGRI L1 dataL2L3 product

Calibration and Validation

AGRI calibration and validation