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 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 | FY-4B |
|---|---|---|
| Weight | 315kg | |
| Dimension | 1353.5mm (length) × 2179.9mm (width) × 1549mm (height) | |
| Bands | Long-wave: 700∼1130cm-1 Mid-wave: 1650∼2250cm-1 Visible: 0.55∼0.90μm |
Long-wave: 680∼1130cm-1 Mid-wave: 1650∼2250cm-1 Visible: 0.55∼0.90μm |
| Spectral resolution | Long-wave: 0.8cm-1 Mid-wave: 1.6cm-1 |
0.8cm-1 |
| Spatial resolution | Infrared: 16km SSP Visible: 2km SSP |
Infrared: 12km SSP Visible: 1km SSP |
| Temporal resolution | 60 min | 45 min |
| Radiation calibration accuracy | 1.5K | 0.7K |
| Spectral calibration accuracy | 10ppm | better than 10ppm |
| Band | Range | Sensitivity | Calibration accuracy |
|---|---|---|---|
| LWIR | 680 ~ 1130 cm-1 | 0.5 ~ 1.1 mW/(m2sr cm-2) | 1 K |
| MWIR | 1650 ~ 2250 cm-1 | 0.1 ~ 0.14 mW/(m2sr cm-2) | 1 K |
VIS band
○ SNR: S/N ≥ 200 (ρ=100%)
○ Calibration accuracy: 10 ppm
IR bands:
| Band | Range | Sensitivity | Calibration accuracy |
|---|---|---|---|
| LWIR | 680 ~ 1130 cm-1 | 0.5 mW/(m2sr cm-2) | 0.7 K |
| MWIR | 1650 ~ 2250 cm-1 | 0.1 mW/(m2sr cm-2) | 0.7 K |
VIS band:
○ SNR: S/N ≥ 200 (ρ=100%)
○ Calibration accuracy: better than 10 ppm
Scan range of FY-4A GIIRS (104.7°E)
Scan range of FY-4B GIIRS (133°E)
| Satellite | Instrument | Datasets |
|---|---|---|
| FY-4B | GIIRS | L1 data, L2L3 product |
| FY-4A | GIIRS | L1 data, L2L3 product |
GIIRS