Medium Resolution Spectral Imager-LL (MERSI-LL)

Description

Succeeding the IR channel settings of  MERSI-II, MERSI-LL has an additional low-light level channel with wide spectral range, which gives FengYun satellite the ability of visible band observation at night-time for the first time. MERSI-LL has 7 channels, including 1 low-light channel and 7 infrared channels. The two infrared window channels have the spatial resolution of 250m at nadir and the others are 1000m. Onboard calibration is the main calibration method for MERSI-LL, and it can provide full moon disk observation for the lunar calibration. MERSI-LL has calibration requirements at least of 10% on low-light channel during the day and 50% at night (the expected requirements reach 5% during the day and 10% at night), and the IR channels calibration requirements are at least 0.4 K and expectation is 0.2 K.

Characteristics

Satellite FY-3E 
Number of Channels 7
Spatial Resolution 250m / 1000m

Characteristics

No. Center wavelength(μm) Bandwidth(nm) Spatial resolution (m) Minimum/expected sesitivity (SNR or NEΔT) Minimum/expected accuracy (% or T)
1 0.7 400 1000 200 (Daytime)
10% / 5% (Daytime)
7 (Nighttime) 50% / 10% (Nighttime)
2 3.8 180 1000 0.25K 0.4K / 0.2K
3 4.05 155 1000 0.25K 0.4K / 0.2K
4 7.2 500 1000 0.30K 0.4K / 0.2K
5 8.55 300 1000 0.25K 0.4K / 0.2K
6 10.8 1000 250 0.30K 0.4K / 0.2K
7 12.0 1000 250 0.30K 0.4K / 0.2K

Data and Products

Satellite Instrument Datasets
FY-3E MERSI-LL L1 dataL2L3 product

Calibration and Validation

MERSI-LL calibration and validation

MERSI-LL SRF (ZIP)

MERSI-LL

MERSI-LL