• Forum
• SITREP
• Military
• WMD
• Intelligence
• Homeland Security

• Space

• Introduction
• Systems
• Facilities
• Agencies
• Countries
• Hot Documents
• News
• Reports
• Policy
• Budget
• Congress
• Links

• Public Eye

L-SAR4 / LTDC-4A

The Land Exploration-4 satellite is a remote sensing research satellite listed in the country's Medium and Long Term Development Plan for Civilian Space Infrastructure (2015-2025.) The satellite operates in an inclined geosynchronous orbit and is equipped with a synthetic aperture radar payload with high resolution, wide coverage, multiple modes, and lightweight advantages. China National Space Administration (CNSA) oversaw the organization of the launch and manages the satellite program. The satellite was developed by the China Academy of Spacecraft Technology (CAST).

CASC had officially reported a "20 m resolution high-orbit radar satellite" going to be launched this year. "Ludi Tance-4A" "LTDC" part stands for "Land Probing" and was used as a different name for L-Band radar satellites L-SAR-01A & B launched Jan. & Feb. 2022 as "LTDC-1A/B".

Compared with low-orbit satellites and optical satellites, the Land Exploration-4 satellite combines the advantages of a short revisit period and large imaging swath in high-orbit observation with the advantages of microwave observation that is not limited by weather conditions (all-weather) and not limited by lighting conditions (all-day), which can improve the accuracy and efficiency of identifying abnormal changes in weather and enhance the nation's comprehensive disaster prevention and control capabilities.

China successfully sent the Land Exploration-4 01 satellite, the world's first high-orbit synthetic aperture radar (SAR) satellite, into a preset orbit via a Long March-3B carrier rocket from the Xichang Satellite Launch Center in Southwest China's Sichuan Province at 1:26 am on 13 August 2023. The satellite is the world's first high-orbit SAR satellite that has entered the engineering implementation phase. Able to provide all-weather and all-day observation of China's territory and surrounding areas, it will further improve the country's space-based disaster monitoring system and is of great significance for comprehensively boosting the country's disaster prevention, reduction, and relief capabilities.

With the satellite now in orbit, it will enrich China's key regional observation methods and provide all-weather and all-day observation of China's territory and surrounding areas, meeting the needs of disaster prevention and reduction, earthquake monitoring, land and resources surveying, as well as applications in industries such as the marine, water conservancy, meteorology, agriculture, environmental protection, and forestry industries, according to the press release.

State departments led by China's Ministry of Emergency Management, including the Ministry of Natural Resources, Ministry of Water Resources and China Meteorological Administration, are key users of the satellite and they will carry out construction of ground systems and operation systems according to their specific needs.