Photos from the sky! The first batch of 10 images from the Science Satellite 1 were officially released in Beijing

On December 20, 2021, the first batch of 10 images from the Sustainable Development Science Satellite 1 (SDGSAT-1) were officially released in Beijing, including low-light, multi-spectral and thermal infrared imaging images of many regions and cities such as the Yangtze River Delta, Shandong Peninsula, Namtso in Tibet, Aksu in Xinjiang, Beijing, Shanghai and Paris, France.

The SDGSAT-1 satellite was successfully launched at the Taiyuan Satellite Launch Center on November 5, 2021. It is the world's first Sustainable Development Goals monitoring satellite and a scientific satellite dedicated to serving the United Nations 2030 Agenda for Sustainable Development (hereinafter referred to as the "2030 Agenda"). It was developed by the Chinese Academy of Sciences' "Earth Big Data Science Project" pilot project and is the first launch satellite planned by the International Research Center for Big Data on Sustainable Development (CBAS).

In response to the monitoring and evaluation needs of sustainable development goals, SDGSAT-1 is equipped with three payloads: thermal infrared, low-light and multi-spectral imagers, to achieve a detailed depiction of the interaction between human activities and the natural environment. The thermal infrared imager has high-resolution wide-band observation capabilities and can obtain data with a width of 300 kilometers and a resolution of 30 meters. It is the first time in China to adopt a full-optical path low-temperature optical system design, which can distinguish a temperature difference of 0.2 degrees Celsius under a large dynamic range. The low-light and multi-spectral imagers use an innovative design of a shared optical path, which ensures the consistency of data observation while achieving data acquisition capabilities with a resolution of 10 meters. At the same time, the SDGSAT-1 satellite is designed with multiple data acquisition modes such as "thermal infrared + multi-spectral", "thermal infrared + low-light" and single-payload observation, which can realize multi-payload, all-day collaborative observation. Different on-board calibration modes are designed for the three payloads to meet the data acquisition efficiency and quantitative detection needs for serving global sustainable development.

Currently, the SDGSAT-1 satellite is in the on-orbit testing phase, and all functions are normal, with performance indicators meeting mission requirements. After the satellite is in orbit and operating normally, it will provide continuous and stable global data support for the monitoring, evaluation and scientific research of sustainable development goals. (Qi Fang, Guangming Daily Omnimedia reporter)

1. Low-light-level imager images

The low-light imager has the ability to reflect the level of social and economic development and human settlement patterns by detecting the intensity and distribution of nighttime lights. The SDGSAT-1 low-light imager is designed with one panchromatic band and three color bands. The spatial resolution of panchromatic and color low-light data is 10 meters and 40 meters respectively, creating a color low-light detection mode. Using its observation data, combined with economic, social, and humanities data, it can provide services for the monitoring, evaluation, and scientific research of related indicators such as housing conditions, human settlements, and transportation in SDG 11 (sustainable cities and communities), as well as coastal light pollution, marine fisheries, and marine oil and gas production in SDG 14 (underwater life).

1. Low-light remote sensing satellite image of Beijing

Description: The image shows the urban structure of Beijing in detail. The main urban ring road traffic and urban road network, Tiananmen Square, Capital Airport and other landmark buildings are clearly visible; the lighting information reflects the remarkable development achievements of the city's sub-center, Yizhuang Economic Development Zone, Daxing, Fangshan and other places. The color low-light data clearly shows that the main urban area of ​​Beijing is dominated by warm yellow lights (high-pressure sodium lamps), while the emerging areas such as the city's sub-center, Yizhuang Economic Development Zone, Daxing, Fangshan, Shijingshan and the eastern part of Changping are dominated by medium-toned green lights (LED lights); the Water Cube (blue), the National Grand Theater (blue + red) and the city neon lights (red, purple lights, orange, etc.) can be clearly identified, showing a colorful city night scene and reflecting the economic development and night activity levels of each region.

2. Low-light-level remote sensing satellite images of Shanghai

Description: The image shows the urban structure of Shanghai in detail. The brightest areas are the Bund and Lujiazui areas along the Huangpu River, and the road network structure outside the city is clear. Changxing Island and Chongming Island are on the upper right, and Pudong Airport is on the right. The lighting information reflects that Pudong's development is large-scale and has achieved remarkable results. Baoshan District, Jiading District, Qingpu District, Songjiang District and Fengxian District are distributed around Shanghai, with active economic activities.

3. Low-light-level remote sensing satellite images of the Yangtze River Delta

Description: The image shows major cities in the Yangtze River Delta, such as Shanghai, Hangzhou, Suzhou, Ningbo and Yiwu, as well as small and medium-sized cities, as well as facilities such as Zhoushan Green Petrochemical Base, Yangshan Port and East China Sea Bridge. For the first time, high-resolution color low-light data is used to present the distribution of nighttime lights in the Yangtze River Delta region in detail, reflecting the pattern and level of economic development in the region.

4. Low-light remote sensing satellite image of Paris, France

Description: Paris, France is a typical international metropolis. The image shows that the city of Paris has a radial structure. The city core area centered on the Arc de Triomphe has the highest lighting brightness and is the area where economic activities are concentrated.

2. Multispectral Imager Images

The SDGSAT-1 multispectral imager is designed with 7 bands and a spatial resolution of 10 meters. Multispectral data has the characteristics of wide bandwidth and high signal-to-noise ratio. Its band setting is suitable for monitoring water color index, transparency and suspended solids in various turbid water bodies, and can serve the monitoring and evaluation of water quality monitoring, offshore ecological environment, coastal aquaculture and aquatic plant distribution in SDG 6 (clean drinking water and sanitation facilities) and SDG 14 (underwater life). In addition, multispectral data can also be used to extract information and analyze changes in glacier area and changes, snow melting status, vegetation coverage, etc., and can provide services for monitoring and evaluation of relevant indicators such as SDG 13 (climate action) and SDG 15 (terrestrial life).

1. Multi-spectral remote sensing satellite image of Namtso Lake in Tibet

Description: The Namtso Nature Reserve in the image has distinct layers of lake water color, and the different colors reflect the lake's water quality, depth and other characteristics; the snow-capped Nyainqentanglha Mountains to the south are crisscrossed with ravines, reflecting the high altitude and cold landform characteristics of the area.

2. Multi-spectral remote sensing satellite image of Jiaozhou Bay, Shandong

Description: The right side of the image is the urban area of ​​Qingdao (partial), the left side is the West Coast New Area, and the Jiaozhou Bay Cross-sea Bridge spans the middle. The Mo Shui River in the northeast and the Dagu River in the northwest flow into Jiaozhou Bay, and the direction of the river flow is clearly discernible. The bay is calm, which is conducive to the sedimentation of muddy suspended matter in the water, and the water is relatively clear; the seawater flow rate outside the bay increases, and the muddy suspended matter is not easy to settle, and it is turbid light yellow.

3. Multi-spectral remote sensing satellite image of the Yellow River estuary

Description: The Yellow River estuary is colorful and has distinct layers. The image shows the gradual mixing of river water and seawater after the Yellow River flows into the sea, and the sediment entering the sea moves with the mixed water and gradually dissipates.

3. Thermal infrared imager images

The SDGSAT-1 thermal infrared imager is a new design with three bands, a spatial resolution of 30 meters and a swath width of 300 kilometers. It has the ability to identify temperature differences of 0.2 degrees Celsius, and can accurately detect land surface and water surface temperatures, dynamic changes in farmland water and heat, urban thermal energy distribution, etc. It can provide basic data for crop growth, the environment for the occurrence of pests and diseases, energy consumption, and surface temperature changes. It can serve the monitoring and evaluation of relevant indicators such as SDG 2 (zero hunger), SDG 7 (clean energy) and SDG 13 (climate action).

1. Thermal infrared remote sensing satellite image of Aksu region in Xinjiang

Description: Thermal infrared image of Aksu area at night. In the color image, bright orange represents higher temperature, and blue-purple represents lower temperature. The upper part of the image is the northern mountainous area, where the valley temperature is high and the ridge temperature is low. The lower part is the Tarim River and lake reservoirs, where the nighttime brightness temperature is greater than the surrounding objects; the urban residential areas (Aksu City and Aral City) show higher temperatures. In the partial black and white image, the degree of brightness and darkness represents the brightness temperature. The center is the Construction Corps farm. The many bright strips visible are winter rest plots that have frozen after irrigation, and the dark areas are relatively dry sandy land.

2. Thermal infrared remote sensing satellite image of the Ulan Ula Lake area in Qinghai

Note: Ulan Ula Lake and the six lakes in the southeast corner are dark because the lake water has a lower brightness temperature than the land; the dark target in the middle of the image is high-altitude cold clouds, and the dark target in the southeast is snow on the top of the mountain, and the snow cover has a low brightness temperature; the temperature difference caused by the topography is clearly discernible.

Source: Guangming Daily Omnimedia reporter Qi Fang

Editor: Wang Yuanfang

Editor: Zhu Xiaofan Chang Ying