Zi Yuan, Huanjing, Tansuo, and Tianhui focused on land masses. In the meantime, China had been working on a series of satelhtes devoted to maritime observations. These would require a quite different set of instruments. The potential of maritime observations had been well known ever since the American Seasat, the Franco – American Topex/Poseidon and Jason, and the Russian Okean. Theoretical work had been undertaken in China in the 1970s. The concept was especially promoted by Jiang Jing Shan, who had seen the other examples and managed to obtain project 863 funding in the 1980s. The program was eventually approved in 1997 . It was developed for the Science and Technology Department of the State Oceanic Administration and planned as the first of a series of regular launchings of observation satellites able to photograph the ocean in three-dimensional color images. The aim of the series was to monitor the seas, tidal zones, offshore sandbanks, and the marine environment, picking out pollutants and sand pouring into the sea. In particular, it would focus on China’s coastal seas (Bohai, Huanghai, Donghai, and Naihai).
The first satellite, Haiyang 1 (later called Haiyang 1A), the Chinese word for “ocean”, was brought into orbit on 15th May 2002 as a companion of Feng Yun 1-4 (see above). Haiyang was a small (1.2 x 1.1 x 1-m), 365-kg oceanographic satelhte using the CAST968 bus. The original orbit with Feng Yun 1 was not suitable for Haiyang so, during the last week of May, a motor lowered Haiyang’s altitude to an operational height of 792-795 km, 100.7 min.
Haiyang had a 10-band three-dimensional ocean color and temperature mechanical scanner made in Shanghai with a swath of 1,164 km, resolution of 1,100 m, a revisit time of three days, and a four-band push-broom Charge Couple Device CCD camera made in Beijing of 500-km swath with 250-m resolution and a seven-day revisit time. The aim was to observe the oceans for chlorophyll,
plankton, fluorescence, sediment, temperature, ice and pollution, chlorophyll concentrations, surface temperatures, silting, pollutants, sea ice, ocean currents, and aerosols. It crossed China from 08:35 to 10:40 every morning, making observations while downloading data from the 2GB memory tape recorder over a 22min period at 5 MB/sec .
The original program envisaged a test satelhte with a two-year lifetime
(IA) before an operational satellite
(IB) . The satelhte was a success and relayed back high-quality images, from the Strait of Qongzhou to Mexico Bay. Haiyang 1 focused on the Bohai Sea, the Yellow Sea, the East China Sea, and the South China Sea, operating for 685 days to April 2004, making 830 surveys. Four problems were revealed by this test mission. First, its solar cells did not last as long as hoped. Second, the Chinese were not happy with the level of glinting of the Sun on the ocean’s surface and set the equator crossing time back from 10:00 am to 10:30 am to get a better angle on the next satellite. Third, memory was insufficient, so the next satellite was equipped to download not one, but five sets of data during each overpass. Fourth, the swath was too narrow and
Haiyang, China’s pioneering oceanographic was increased to 3,000 km. satelhte. The operational Haiyang IB was
duly launched on 11th April 2007, with a three-year lifetime, three times greater data capacity, higher resolution, greater tolerance to temperature and vibration, 10 computers, and improved solar cells. Its mission was to monitor the temperature of the ocean, track pollution, watch coastal development, and study environmental changes. It flew at 798 km, with weekly repeater orbits.
Like Huanjing, we have a good volume of information on the Haiyang program. Color sea temperature maps were published, such as an average sea temperature map for the Pacific north-west, ice levels and thickness in the Bohai Sea (which freezes for three months every winter), and river sediments entering the oceans. Maps of the
intersections of warm and cold waters have indicated where fish Uke mackerel, squid, and scad may be found. Hiyang made it possible to make estimates of the biological productivity of the ocean, a vital component in the carbon cycle – a slow and tedious process to undertake from ships – presenting not just maps of the seas around China, but a global productivity estimate. Estimates were made of the carbon dioxide partial pressure in the Yellow Sea so as to begin a model for the ocean carbon cycle. Wind and wave maps of the seas between the Philippines and Indo-China were published. Detailed maps were published of both green tide and red tide infestations, both of which had the potential to damage the marine environment, fishing, and tourism (the 2008 green tide affected the Olympics regatta in Qingdao). Sea ice updates were provided. Color maps were published of suspended sediment in the sea around costal zones. The Haiyangs were able to collect data that measured the level of phytoplankton, benthic plants, and autotrophic bacteria in the seas – indicators of the biological productivity of the ocean. The strength of winds and typhoons was measured and wave heights were calculated to 6 cm. Such information would have been infinitely slower and more costly to obtain from sea-based monitoring. In April 2012, it was announced that Haiyang data would soon be available on the internet from the country’s oceanographic administration, presumably on a system like that of CBERS.
Haiyang marked an important advance in remote sensing for China but, according to the program leaders, Jiang Xingwei and Lin Mingsen, China still lagged behind other countries. There was still much to be done to improve accuracy and extend the application of the data . A three-type series was announced. While the Haiyang 1 series concentrated on ocean color monitoring, the Haiyang 2 series would use microwaves to monitor the dynamic ocean environment, while the Haiyang 3 series would use Synthetic Aperture Radar (SAR) for surveillance and
mo 105 по 115 120 125 150 155 140 145 150 \ ( )
Sea temperature map off the China coast, from Haiyang. Courtesy: COSPAR China.
monitoring of the ocean with a mixture of continuous and single-look monitoring with a grid antenna. Next in the Haiyang series would be a duo of Haiyang 1C (morning passes) and ID (afternoon passes).
The first of the next series, Haiyang 2 (also called 2A), was launched on 15th August 2011. A month later, over 15th-17th September, Haiyang 2A maneuvered to a holding orbit of 911-929 km, 99.36°, 103.38 min, before, on 29th September, reaching its final, almost circular orbit of 965-968 km, 99.37°, 104 min, and it was declared operational the following 2nd March. It was announced that, for the first two years, it would follow a 14-day cycle and then a 168-day cycle with a five-day sub-cycle. Its aims were to follow pollution and topography in shallow waters, ocean winds, waves, currents, tides, and storms. Its instruments comprised a microwave radiometer to measure ocean temperature, wind speed, and atmospheric vapor; a dual-frequency Ku and C-band radar altimeter to measure sea level, wind speed, and ocean height; and a radar scatterometer pencil – beam radar to measure wind speed and direction and to monitor ocean conditions. Cross-measurements between them should eliminate any inconsistencies in data. The scatterometer was the achievement of Jiang Jing Shan, who had seen how successful it was on Europe’s ERS satellite and the American Seasat. His design had two rotating antennae, horizontal and vertical. It was designed to measure wind speed within 2 m/sec and wind direction within 20° in a swath of 340 km . It was announced that future missions would follow in 2012 (2B), 2015 (2C), and 2019 (2D).
In addition, China plans a joint oceanographic mission with France: CFOSAT (Chinese French Oceanic Satellite), whose objective is to monitor wind and waves globally for the purposes of marine meteorology (especially severe events), ocean dynamics, climate variability, and the surface processes. Taking advantage of French
CFOSAT, with France, a world leader in oceanography. Courtesy: CNES.
experience in such missions as TOPEX/Poseidon, Jason, and Megatropiques, it is intended to improve knowledge of sea-surface processes, waves, and sea ice, especially in coastal areas. There are two main microwave radar instruments: the Surface Waves Investigation and Monitoring instrument (France), which will not measure wave height, but direction, amplitude, and wavelength; and a scatterometer supplied by China with six rotating beams designed to hit the waves at an angle that can measure their frequency. Launch is set for 2015 on the CZ-2C with data transmitted to both countries. The series is summarized in Table 6.8.
Table 6.8. Haiyang series.
Haiyang 1A 15 May 2002 CZ-4B, piggyback with Feng Yun 1-4
Haiyang IB 11 Apr 2007 CZ-2C
Haiyang 2 15 Aug 2011 CZ-4B
All from Taiyuan.