Advanced Geostationary Radiation Imager (AGRI)

Description

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 14 15
Spatial resolution 0.5~1 km (VIS/near-IR bands)
2~4 km (IR bands)
0.5~1 km (VIS/near-IR bands)
2~4 km (IR bands)
Time for full-disc scanning 15 min 15 min
Sensitivity S/N=200@ρ=100% (reflection bands)
NE∆T=0.2K@300K (IR bands)
S/N=200@ρ=100% (reflection bands)
NE∆T=0.2K@300K (IR bands)
Calibration accuracy 3~5% (VIS/near-IR bands)
1K (IR bands)
3~5% (VIS/near-IR bands)
0.7K (IR bands)

Characteristics

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
Band Center wave length (μm) Band width (μm) Spatial resolution(km) Sensitivity/SNR Main purpose
1 0.47 0.45~0.49 1 S/N≥90(ρ=100%) Aerosol
2 0.65 0.55~0.75 0.5 S/N≥150(ρ=100%)@0.5km S/N≥3(ρ=1%)@1km Fog, cloud
3 0.825 0.75~0.90 1 S/N≥200(ρ=100%) S/N≥3(ρ=1%) Vegetation
4 1.379 1.371~1.386 2 S/N≥120(ρ=100%) S/N≥2(ρ=1%) Cirrus
5 1.61 1.58~1.64 2 S/N≥200(ρ=100%) S/N≥3(ρ=1%) Cloud, snow
6 2.25 2.10~2.35 2 S/N≥200(ρ=100%) S/N≥2(ρ=1%) Cirrus, aerosol
7 3.75 3.50~4.00(high) 2 ≤0.7K(315K) Fire
8 3.75 3.50~4.00(low) 4 0.2K(300K) 2K(240K) Land surface
9 6.25 5.80~6.70 4 0.2K(300K) 0.9K(240K) High level water vapor
10 6.95 6.75~7.15 4 0.25K(300K) 0.9K(240K) Mid level water vapor
11 7.42 7.24~7.60 4 0.25K(300K) 0.9K(240K) Low level water vapor
12 8.55 8.3~8.8 4 0.2K(300K) 0.4K(240K) Cloud
13 10.80 10.30~11.30 4 0.2K(300K) 0.4K(240K) Surface temperature
14 12.00 11.50~12.50 4 0.2K(300K) 0.4K(240K) Surface temperature
15 13.3 13.00~13.60 4 0.5K(300K) 0.9K(240K) Cloud and water vapor

FY-4A AGRI transmittance over wavelength

FY-4A AGRI scan range (104.7°E)

FY-4A AGRI scan range (133°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

FY-4B AGRI SRF (ZIP)

FY-4A AGRI SRF (PDF)

AGRI

AGRI