Anhui Institute of Optics and Fine Mechanics (AIOFM), Hefei Institutes of Physical Science (HFIPS) of the Chinese Academy of Sciences, announced the acceptance of its directional polarimetric camera (DPC-II) on Spet.2, which is the last batch of atmospheric environment detection payloads for GF-5(02) satellite.

AIOFM has also developed Environmental Trace Gas Monitoring Instrument (EMI-II), Greenhouse Gas Monitoring Instrument (GMI-II), and Particulate Observing Scanning Polarization (POSP), which passed the acceptance test in early 2020. The handover of DPC-II marked the project for GF-5(02) undertaken by AIOFM has been completed.

Equipped with seven remote sensing instruments (four of them are developed by AIOFM), GF-5(02), the second hyper-spectral comprehensive observation satellite of China, will offer higher resolution index and possess better hyperspectral observation ability on atmosphere, water, and land. Compared with GF-5 (01), it has many advantages.

Environmental Trace Gas Monitoring Instrument (EMI-II)-higher spatial resolution index
EMI-II is used to obtain hyperspectral remote sensing products from ultraviolet to visible band, and then to quantitatively monitor distribution and change of global atmospheric components. A higher spatial resolution index 24 km is available with EMI-II, compared to 48km with EMI-I. For this operation, it will set a pilot application of hyperspectral remote sensing measurement in terms of monitoring pollution gas, regional air quality and atmosphere composition.

Greenhouse Gas Monitoring Instrument (GMI-II)-optimized for better performance
GMI-II is for detecting main greenhouse gases in the atmosphere, including carbon dioxide and methane, and the auxiliary detection object is O₂ A-band airglow. As an optimized instrument of GMI-I, the design and the key indices, including SNR of the main carbon dioxide detection channel and spectral bandwidth of the auxiliary detection channel, have been further improved.

Directional Polarimetric Camera (DPC-II)- synergetic observation with POSP
Optimized on the basis of DPC-I, DPC-II plays an important role in monitoring atmospheric PM2.5 pollution. It is designed to increase the number of multi-angle observation and improve the spatial resolution. But the highlight is that it realizes synergetic observation with the newly developed POSP.

Particulate Observing Scanning Polarization (POSP)-newly developed cross-track scanning polarimeter
The POSP is a newly developed cross-track scanning polarimeter with highly accurate polarization measurements of bands from near-UV to SWIR (410-2,250 nm). It will form the "Polarization Cross-Fire Suite" with DPC-II.

An on-board calibration device is designed for POSP, which has functions such as on-orbit polarization calibration and solar diffuse reflector-based radiometric calibration. Precise polarization and radiation detection data can be accurately transferred to DPC-II via "Polarization Cross-Fire".

Researchers are testing the performance of EMI-II (Image by WANG Shimei)