HELSINKI — A new Chinese constellation for disaster prevention, early warning and natural resource monitoring will bring yet more players into developing small synthetic-aperture radar satellites in the country.

The “36 Tiangang” constellation project is being led by Tianjin Satcom Geohe Technologies Co., Ltd., with involvement from Satellite (Zhuhai) Aerospace Technology Co, Ltd., and facilities under the Harbin Institute of Technology and backed by the Ministry of Natural Resources.

The project, named after the ancient Chinese name for the Big Dipper asterism, was announced in August in Wenchang. A later signing ceremony took place in Harbin Nov. 30.

The constellation will consist of 36 satellites. The first, a hyperspectral satellite in a 500-kilometer Sun-synchronous orbit with a resolution of 10 meters, is set to launch early next year. Under the 36 Tiangang plan satellite data will be combined with geological survey and monitoring data collected by ground sensors in disaster-prone areas.

The first six satellites are to be launched by June 2022 and will be named for Yunnan province. The full 36-satellite constellation, comprising of panchromatic multispectral, hyperspectral and SAR satellites, is to be completed by the end of May in 2023.

Notably more than half of the subsequent satellites will be SAR satellites, according to CCTV

SAR satellites can gather data day and night, and through all weather conditions and will monitor ground subsidence, deformations from seismic activity, landslides, volcanic activity, and monitor buildings. 

SAR imagery, which is typically more expensive and more difficult to use than optical imagery, is in short supply in China, which is likely a big factor in the new plans.

Current capabilities include the Gaofen-3 satellites as part of the national CHEOS Earth observation program, and the small satellites Hisea-1, developed by Spacety, and Qilu-1. The latter was launched in April, developed by the Innovation Academy for Microsatellites under the Chinese Academy of Sciences and is operated by Shandong Industrial Technology Research Institute.

However, a number of companies and projects are seeking to provide SAR data, notably through partnerships between established state-owned actors and new commercial players. 

Giant state-owned enterprise China Electronics Technology Group (CETC) is working with private satellite manufacturer Spacety to construct a 96-satellite X and C-band SAR constellation named Tianxian

In February, Beijing Smart Satellite Space Technology Co., Ltd., began procurement processes for its own SAR plans. Smart Satellite plans to establish a constellation comprising 12 SAR X-band satellites in 2022. In July, Smart Satellite signed an agreement with CETC’s 12th Institute, a domestic leader in microwave electron vacuum devices and tested a SAR payload on a UAV in October.

Piesat Information Technology Co. Ltd., which develops software for remote sensing image and data processing, in August signed a strategic agreement with GalaxySpace, a Beijing-based satellite manufacturer, for development of a four-satellite Hongtu-1 SAR constellation. Aerospace Hongtu, under Piesat, is also developing a SAR data processing cloud service ecology to lower the threshold of user data processing.

Other entities with SAR plans include F.Squares Technology, reported to be developing a 200-kilogram sat. Zhuhai Orbita also includes a SAR platform in its Zhuhai-1 Earth observation constellation plans.

The SAR market is growing worldwide, with a number of companies developing constellations. Finland’s Iceye already operates X-band SAR satellites while the first operational satellite of San Francisco-based Capella Space, Sequoia, also operates in X-band. 

U.S. startups PredaSAR and Umbra and Japan’s iQPS and Synspective are also developing SAR constellations.

Andrew Jones covers China's space industry for SpaceNews. Andrew has previously lived in China and reported from major space conferences there. Based in Helsinki, Finland, he has written for National Geographic, New Scientist, Smithsonian Magazine, Sky...