Visible and Infra Red Radiometer (VIRR)
Description
This instrument is a copy of the Multi-channel Visible and Infrared Scanning Radiometer (MVISR, 10 channels) that used to fly on FY-1C/D satellites (1999-2011). For the sake of observational continuity, the 10-channel radiometer VIRR onboard FY-3A/B/C remains the same as the MVISR on FY-1C/D. However, it is planned that FY-3D or future FY-3s will not carry VIRR. The VIRR’ work will be taken over by MERSI-2 instrument to be flying on FY-3D and future FY-3s.
Visible-infrared light Scanning Radiometer has ten 1km-resolution spectral channels, including the high sensitivity visible channel. And there are three infrared atmospheric window channels. The primary purpose of Visible-infrared light Scanning Radiometer is to monitor global cloud cover, identification of cloud height, type and phase, aimed at detecting sea surface temperature, monitoring of vegetation growth conditions and types of monitoring and identification of high-temperature of the snow-covered surface at detecting Ocean color, etc.
| Satellite | FY-3A , FY-3B , FY-3C |
|---|---|
| No. Channels | 10 |
| Spatial Resolution | 1.1km |
| Weight | 55kg |
| Power | 45W |
Characteristics
| Central wavelength (μm) | Band range (μm) | Noise equivalent reflectivity ρ(%) / Noise equivalent temperature difference (300K) | Dynamic range (ρ/k) |
|---|---|---|---|
| 0.455 | 0.43~0.48 | 0.05% | 0~50% |
| 0.505 | 0.48~0.53 | 0.05% | 0~50% |
| 0.555 | 0.53~0.58 | 0.05% | 0~50% |
| 0.630 | 0.58~0.68 | 0.1% | 0~100% |
| 0.865 | 0.84~0.89 | 0.1% | 0~100% |
| 1.360 | 1.325~1.395 | 0.19% | 0~90% |
| 1.600 | 1.55~1.64 | 0.15% | 0~90% |
| 3.740 | 3.55~3.93 | 0.3K (FY-3A 0.4K) | 180~350K |
| 10.80 | 10.3~11.3 | 0.2K | 180~330K |
| 12.00 | 11.5~12.5 | 0.2K | 180~330K |
Data and Products
| Satellite | Instrument | Datasets |
|---|---|---|
| FY-3C | VIRR | L1 data, L2L3 product |
| FY-3B | VIRR | L1 data, L2L3 product |
| FY-3A | VIRR | L1 data, L2L3 product |
Calibration and Validation
VIRR