An infrared hyper-spectral vertical sounder, also the first space-borne interferometer that flies in geostationary orbit to take measurements of three dimensional atmospheric structure from interference of split light beams. Technically featured by a 32×4 sensor array plane, a Michelson interferometer working over different infrared bands for large-area, continuous, fast, and accurate vertical air soundings of temperature and humidity.
Satellite | FY-4A |
---|---|
Weight | 315kg |
Dimension | 1353.5mm (length) × 2179.9mm (width) × 1549mm (height) |
Bands | Long-wave: 700∼1130cm-1 (8.85∼14.29μm) Mid-wave: 1650∼2250cm-1 (4.44∼6.06μm) |
Spectral resolution | 0.625cm-1 (actual measurement) |
No. channels | 1650 (actual measurement) |
Spatial resolution | 16km |
Temporal resolution | 768km × 960km (30 min) 4480km × 5000km (60 min) |
Radiation calibration accuracy | 1.5K |
Spectral calibration accuracy | 10ppm |
FY-4A (R&D) | FY-4B (Operational) | |||||||
---|---|---|---|---|---|---|---|---|
Spectral parameters (normal mode) | Range (cm-1) | Resolution | No. channels | Range (cm-1) | Resolution | No. channels | ||
LWIR | 700∼1130 | 0.8 | 538 | LWIR | 700∼1130 | 0.625 | 688 | |
S/MIR | 1650∼2250 | 1.6 | 375 | S/MIR | 1650∼2250 | 1.2 | 500 | |
VIS | 0.55-0.75μm | 1 | VIS | 0.55-0.75μm | 1 | |||
Spatial Resolution | L/S/MWIR | 16km | L/S/MWIR | 8km | ||||
VIS | 2km | |||||||
Area | China | 5000 × 5000 km2 | China | 5000 × 5000 km2 | ||||
Mesoscale | 1000 × 1000 km2 | Mesoscale | 1000 × 1000 km2 | |||||
Temporal resolution | China | <1 hour | China | <1 hour | ||||
Mesoscale | <½ hour | Mesoscale | <½ hour | |||||
Sensitivity (mW/m2sr⋅cm-1) | LWIR | 0.5∼1.1 | LWIR | 0.3 | ||||
S/MIR | 0.1∼0.14 | S/MIR | 0.06 | |||||
VIS | S/N>200(ρ=100%) | VIS | S/N>200 (ρ=100%) | |||||
Calibration accuracy (radiation) | 1.5k (3σ) | 1.0k (3σ) | ||||||
Calibration accuracy (spectrum) | 10 ppm (3σ) | 5 ppm (3σ) | ||||||
Quantization (bits) | 13 | 13 |
Satellite | Instrument | Datasets |
---|---|---|
FY-4B | GIIRS | L1 data, L2L3 product |
FY-4A | GIIRS | L1 data, L2L3 product |