Classification of the land around Yamoussoukro, capital of Côte d’Ivoire, using Sentinel-2; generated using the Copernicus Data Space Ecosystem. Data courtesy of ESA/Copernicus
This week, we are looking at Earth Observation (EO) developments in Asia and Africa – China’s first EO launches of the year and the Côte d’Ivoire latest Land Cover map using Sentinel-2 data.
China’s EO Satellite Launches
In our first blog of the year, we noted that China’s EO launches were likely to continue in 2024, and they have already fulfilled that prediction.
The first launch occurred on Friday 5th January, when a Kuaizhou 1A rocket took off from the Jiuquan Satellite Launch Center carrying four Tianmu-1 commercial weather satellites. They were put into sun-synchronous orbits at an altitude of just above 500 km. The satellites use GNSS radio occultation for meteorology measurement, detecting changes to signals transmitted by navigation satellites such as GPS, Galileo, & Beidou. These launches join other satellites in orbit, creating a 22-strong constellation that is owned by Xiyong Microelectronics Park, a subsidiary of China Aerospace Science and Industry Corporation.
Just under a week later, on the 11th January, the Chinese Gravity-1 commercial carrier rocket completed its maiden mission, putting three Yunyao-1 EO satellites into orbit. Similar to Tainmu-1, these are commercial meteorological satellites orbiting around 500 km altitude and aim to provide measurements for commercial data services. The satellites were developed by Chang Guang Satellite Technology for the Tianjin-based Yunyao Yuhang company, who also have the ambition to develop a constellation for global weather forecasting and other services.
Gravity-1’s launch was also notable as it set the world record for the largest mass for a solid-propellant launch vehicle. Interestingly, the rocket took off from Dong Fang Hang Tian Gang mobile sea platform in the Yellow Sea.
Earth Observation Data for Land Cover Maps
Last month, the CĂ´te d’Ivoire’s Center of Geographical Information and Digital (CIGN) launched its 2020 land cover map online. It was created using a mosaic of Sentinel-2 images at 10 m spatial resolution with 28 different land use classes – including seven classes of forest; 11 classes of cultivated land, three classes of grassy land, three classes of wetlands, two classes of inhabited land, and two classes of other lands.
The map aims to support the agricultural sector in dealing with environmental issues, particularly cocoa producers. Cote d’Ivoire is the world’s top cocoa producer, annually producing over 2 million tons, but in the last 100 years has lost almost 90% of its natural forests. This is critical as the European Union is the biggest market for the country’s cocoa, and last year, they determined that they would not purchase products contributing to deforestation, which could have a massive impact on the Cote d’Ivoire cocoa industry. Therefore, the country’s producers are moving towards sustainable production to respond to these environmental requirements, and it is believed that this land map will support this transition.
The country’s first land map was produced in 2016, and the CIGN has used Google Earth Engine and machine learning algorithms, such as Random Forest, to develop the latest versions. This approach has delivered an 80% cost reduction and enhanced data quality, with the country aiming to update the map every two years. The map can be found on the Cote d’Ivoire area of the Africa Geoportal developed by ESRI.
The picture at the top of the blog isn’t from their 2020 Land Map. However, it is a land cover classification using Sentinel-2 data, generated on-the-fly by the Copernicus Data Space Ecosystem. It shows the Cote d’Ivoire capital city, Yamoussoukro, just below the centre, with the airport to the north-west. Above the airport is part of Lake Kossou, an artificial lake created in 1973 by damming the Bandama River.
Summary
While the number of EO satellites in space continues to grow, it is also exciting to see examples and applications of how EO data is being used to make a difference in the world.
