Green Lasers in the Sky (remote-sensing satellite)


Senior Member.
superimposed, contrast-enhanced image of the scan:
Screenshot_20230211-143652_Samsung Internet.jpg

Last night (early morning 2023-1-28 HST) was cloudy on Maunakea. But our Subaru-Asahi Star Camera captured quite an interesting view -- green laser lights coming from the sky! It was only a second or less -- but our keen viewers did not miss the event! That was so a mysterious view, then later the viewers got a conclusion from the information on the net -- it could be a remote-sensing laser (altimeter called ATLAS) from ICESat-2/43613 (BUT see below: different conclusion emerged!)! [..]

** Correction 2023-02-06 ! *** According to Dr. Martino, Anthony J., a NASA scientist working on ICESat-2 ATLAS, it is not by their instrument but by others. His colleagues, Dr. Alvaro Ivanoff et al., did a simulation of the trajectory of satellites that have a similar instrument and found a most likely candidate as the ACDL instrument by the Chinese Daqi-1/AEMS satellite.
Content from External Source


China’s first satellite dedicated to comprehensive monitoring of the atmospheric environment, named Daqi-1, also known as Atmospheric Environment Monitoring Satellite (AEMS) and developed by the Shanghai Academy of Spaceflight Technology (SAST) in Shanghai, is designed to operate in sun-synchronous orbit. Daqi-1 can monitor fine particle pollution like PM2.5, pollutant gases including nitrogen dioxide, sulfur dioxide and ozone, as well as carbon dioxide concentration. It combines both passive and active sensing, which can realize comprehensive monitoring of the atmospheric environment in a better way, according to a chief designer with SAST. The detection accuracy of fine particles and carbon dioxide column concentration by Daqi-1 has reached the international advanced level, the chief designer said. The atmospheric detection lidar deployed on the satellite is also the world's first that is capable of detecting both atmospheric aerosols and carbon dioxide.
Looking into the papers written about the ACDL (Aerosol and Carbon dioxide Detection Lidar) that the Daqi-1 spacecraft has on board, it looks like it is able to eject green (532nm) but also IR like 1064 and 1575. Quite advanced design, as it is able to produce altitude resolved hyperspectral data.