# Review of Satellite Remote Sensing of Carbon Dioxide Inversion and Assimilation
## 2 CO2 Observation, Datasets, Global Related Research
### China Satellite  
In 2016, China launched the TanSat satellite, which is the third international satellite dedicated to high-precision greenhouse gas detection. TanSat is equipped with two main instruments: Atmospheric Carbon Dioxide Grating Spectrometer (ACGS) and Cloud and Aerosol Polarisation Imager (CAPI). The satellite's primary goal is to monitor global CO\({}_{2}\) concentrations with high spatial and spectral resolution, covering the entire world, China, and other key regions. The top-tier product from TanSat is the radiospectral data, with CO\({}_{2}\) inversion accuracy of 1% (1-4 ppm). The Institute of Atmospheric Physics of the Chinese Academy of Sciences developed a high-precision inversion algorithm called IAPCAS, which was used to generate the first global CO\({}_{2}\) distribution map from TanSat's data as Figure 6 shown [23]. Following TanSat, China launched the Fengyun-3D (FY-3D) and Gaofen-5 (GF-5) meteorological satellites after 2017. These satellites primarily measured column concentrations and global distribution changes of CO\({}_{2}\) and CH\({}_{4}\). In 2021, China further advanced its capabilities with the launch of the hyperspectral observation satellite GF5-02, which carries the GMI payload for enhanced measurements. Figure 6: First global map of carbon dioxide distribution. Planned Future Launches of Remote Sensing Satellites CO\({}_{2}\)  
In the future, several CO\({}_{2}\) observing satellites are planned for launch. The next-generation satellite in the GOSAT series, GOSAT-GW (Global Observing Satellite for Greenhouse Gases and the Water Cycle), will launch after 2024. It will carry the TANSO-3, a third-generation thermal infrared and near-infrared carbon-observation grating imaging spectrometer, offering better spatial coverage of greenhouse gases concentrations and addressing the continuous detection limitations of GOSAT and GOSAT-2. The MicroCarb mission, a French-British satellite collaboration, aims to launch in early summer 2025. It will monitor CO\({}_{2}\) exchanges between sources and sinks, with a 13.5 km strip width, 4.5 km (in cross-tracks) \(\times\) 9 km (along-tracks) spatial resolution, and a 21-day repeat cycle. The European Space Agency's Copernicus Anthropogenic CO\({}_{2}\)-Monitoring Mission (CO\({}_{2}\)M) program, starting in 2025, will consist of two satellites. Its main instrument, the Infrared Spectrometer (ISI), features a 2 km \(\times\) 2 km resolution and a 250 km wide observational bandwidth [24] with simultaneous imaging observational capability for monitoring anthropogenic CO\({}_{2}\) emissions. The Carbon Mapper Coalition, in collaboration with public and private partners, announced on 15 April 2021, its plan to deploy an innovative hyperspectral satellite constellation designed to pinpoint, quantify, and track point-source methane and CO\({}_{2}\) emissions. Phase 1, currently underway, involves the development of the first two satellites by Planet and NASA's Jet Propulsion Laboratory (JPL), also a member of the Carbon Mapper Coalition, with a planned launch in 2024. Phase 2, in development, will expand into an operational multi-satellite constellation starting in 2025. On 16 August 2024, the Carbon Mapper Coalition launched Tanager-1, the first satellite of Phase 1, to improve transparency regarding methane and CO\({}_{2}\) super-emitters and encourage global action. Tanager-1 is equipped to detect, locate, and measure these super-emitters from space. JPL also plans to launch a second Tanager satellite later, which will be outfitted with an imaging spectrometer developed by JPL. China expects to launch the second-generation carbon satellite (TanSat-2) in 2025. TanSat-2 is a satellite cluster consisting of two to three satellites measuring XCO\({}_{2}\) at an across-track swath of 2900 km and with a pixel size of 2 km \(\times\) 2 km. TanSat-2 will add the short-wave infrared channel of 2.305\(\sim\)2.385 um to the first-generation carbon satellite (TanSat) for CH\({}_{4}\) and CO detection.