# Present and Future Marine Microwave Satellite Missions in China
## 1 Introduction  
Ocean satellite remote sensing refers to the use of remote sensors for long-distance non-contact observations of marine areas. It has the unique advantage of large-scale, all-day, all-weather real-time imaging observations, and is an important means for global marine environmental monitoring. Through ocean satellite remote sensing, the processes from data to information and from information to knowledge can be obtained. The international application of ocean satellite remote sensing began in 1960 [1]. The United States successfully launched the world's first meteorological satellite \"ITROS-1\" [2] and obtained the sea surface temperature field from an altitude of approximately 700 km. This achievement marked the beginning of the development of oceanographic research using satellite data. In 1978, the United States launched two satellites, \"Nimbus-7\" [3,4] and \"NOAA-1\" [5], for the purpose of obtaining satellite observations of global marine ecological environments and dynamic environments using various frequency sensors, respectively. This was essentially the prelude to marine satellite remote sensing. However, the use of marine remote sensing technology in China started late. During the 1960s [6], airborne infrared thermometers and airborne laser wave height meters were developed and tested at sea. Then, in the 1970s, meteorological satellite data from the United States and Japan were received for marine meteorological analyses and sea ice observations [7,8]. During the 1980s, China invested a great deal of human and material resources into the development of marine remote sensing technology and achieved major technological breakthroughs. In October of 1983, the State Oceanic Administration, Ministry of Aerospace Industry, and the Chinese Academy of Sciences jointly completed the \"Report on the Development of Marine Satellite Project\" and the \"Special Report on the Comprehensive Demonstration of Marine Satellite Technology Economy,\" which were submitted to the State Council. Since then, China's marine satellite work has entered the stage of basic research and technical preparation. On 7 September 1988, China's firstmeteorological satellite with two ocean-colour channels (FY-1) was successfully launched. In the 1990s, the development of marine remote sensing technology reached a new level. In May of 1996, the General Satellite Department of the State Oceanic Administration was established. And in December of the same year, a comprehensive technical and economic demonstration of an oceanic colour satellite passed the review, and was listed in the national \"Ninth Five-Year\" satellite launch plan. Moreover in 1997, China successfully achieved the independent reception of SeaWiFS oceanic colour satellite data of the United States, which provided high-quality, near real-time satellite data for the research and application of marine remote sensing technology in China. The white paper China Aerospace (issued in November of 2000) made it clear that the oceanic satellite series was an important part of China's long-term and stable satellite Earth observation system. In 2001, China established the National Satellite Ocean Application Service. This was another step in the construction of China's remote sensing satellite application system, followed by the establishment of the Meteorological Satellite Application Center and the Resource Satellite Application Center, and marked the formation of a framework for the integrated development of China's remote sensing satellite system. In 2002, China launched its first oceanic colour satellite (HY-1A), which symbolized that the development of marine remote sensing technology in China would enter a new stage and accomplish the development of marine satellites from scratch. Then, on 11 April 2007, China's second marine satellite (HY-1B) was successfully launched, which signified the transition of oceanic colour satellites from experimental application types to operational service types.