Blue Marble image of the Earth taken by the crew of Apollo 17 on Dec. 7 1972.
Image Credit: NASA
It won’t have escaped your notice that COP26 is taking place in Glasgow in the UK this week. There are a lot of articles coming out on how Earth Observation (EO) can support the measurement and monitoring of various aspect of climate change, and so we thought we’d look at some of the other remote sensing stories and articles and leave COP26 to others.
Despite President Xi not attending Glasgow in person, we’re going to start with China, who launched its latest EO satellite on the 27th October from the Jiuquan Satellite Launch Center. Jilin-1 Gaofen 02F is a high-resolution optical satellite, which was sent into a sun-synchronous orbit. This is the latest satellite in the Jilin-1 constellation being developed by Chang Guang Satellite Technology Corporation, which is expected to consist of up to 138 satellites by the end of the decade offering various types of remote sensing capabilities.
Jilin-1 Goafen-02F has a spatial resolution of approximately three metres in multi-spectral mode, and 0.75 metres in panchromatic mode. The sensors operate through a pushbroom approach, and in multispectral mode it images across four optical and near-infrared bands.
Despite the name this constellation is different to the Gaofen imaging satellites operated by the Chinese Government as part of the China High-resolution Earth Observation System (CHEOS); gaofen means ‘high-resolution’; which is why it is used by multiple satellites. This launched also marked the milestone of the most ever space launches in a single year by China. During 2021, China has had 40 launches, one more than it achieved in 2020, and is slightly ahead of the United States for 2021.
The second element that caught our attention had parallels with a recent blog highlighting the death of a large number of seabirds in the north east of England and Scotland. It was reported that there have been a large number of fish deaths in the river Kameng in Arunachal Pradesh, in India, after the river itself turned black.
Initial investigation from satellite imagery has indicated that the deaths are not pollution related and are believed to be caused by low dissolved oxygen levels in the river following landslides. A high content of total dissolved solids have been found in the river, with 6,800 mg per litre against the normal range of 300-1,200 mg per litre. Although potentially a natural phenomenon, other potential reasons have been given such as construction activities. Further work is ongoing, using satellite data, to try and determine the ultimate cause of the change in river colour and fish die-off.
Finally, a newly published research paper describes how a Univeristy of Arizona led team of researchers has identified 478 ancient Mesoamerican ceremonial complexes using airborne lidar remote sensing. The rectangular and square complexes, which are likely to be ritual gathering sites and estimated to date from 1050 to 400 BC, were discovered across the Olmex region of Mexico and in the western Maya regions. The researchers also identified that the Olmec centre of San Lorenzo had a central rectangular space, possibly providing the spatial template for the other sites that suggests the Olmec and Maya people interacted and had a greater relationship than previously thought.
Publically available lidar data was originally collected by the Mexican governmental organization Instituto Nacional de EstadÃstica y GeografÃa, covering 32,800-square-miles, allowing the researchers to investigate a wide area before following up with high-resolution lidar on specific areas of interest.
The paper titled ‘Origins and spread of formal ceremonial complexes in the Olmec and Maya regions revealed by airborne lidar’ by Inomata & Fernandez-Diaz et al was published in the journal Nature Human Behaviour last week.
All of this shows that not everything is happening in Glasgow, although we hope the delegates in Glasgow make the commitments and take the actions necessary to combat climate change.
