The HY-2A satellite ground application system is one of five HY-2A satellite project systems, which has the function of satellite data receiving, processing, calibration and validation, and data application etc. HY-2A satellite ground application system has steady receving system at Beijing, Sanya and Mudanjiang station, which can receving real time data in the waters around China. In addition, it has some subsystem, such as data preprocessing, processing, precise orbit determination, data archiving and distribution, data application etc in the Beijing data precessing center, which can processe all level data of the HY-2A satellite and distribute to user every day. In this paper, it is shown an overview of HY-2A satellite ground application system and an introduction to some main subsystem of HY-2A satellite ground application system, such as subsystem structure, function and operational flow etc.
Design scheme and implementation for HY-2 ground segment is introduced in this paper. Mission control subsystem is responsible for task scheduling，and system monitor，is nerve center of ground segment. Mixture of C/S and B/S architecture is used for operational and control system (OCS) by its characteristic.Mission control subsystem of HY-2 has three types of scheduling task：real time scheduling task，fixed time scheduling task，data reprocessing scheduling task. In order to reduce scheduling complexity，layered scheduling model is used because of complexity of data processing procedure. Automatic operation pattern is used，making plans in advance，distributed task scheduling，centralized operational system status monitor.
Using cone scanning method, microwave radiometer of HY-2 satellite measures the SST and the atmosphere of the earth. This article represents one geolocation method applied to the microwave radiometer of HY-2 satellite according to the geometry model. The image of microwave radiometer was geolocationed with this method, and the result was evaluated at last.
Sea surface wind speed has a very important role in the transfer of kinetic energy in the ocean, and the exchange of the matter and energy in the air-sea surface. There are three payloads on HY-2 satellite which can be used to detect the sea surface wind speed. The payloads are radar altimeter, microwave scatterometer and scanning microwave radiometer. The difference is that altimeter can measure the wind speed at the nadir point of the HY-2 satellite, microwave scatterometer can detect the wide swath wind field, and radiometer can measure the wide swath wind speed only. In order to analyze the capacity of the three payloads, in this study, the Usagi Typhoon is selected for comparing the ability of the three payloads to measure the wind speed. It turned out that when the wind speed is smaller than 20 m/s, the wind from altimeter is much the same as from microwave scatterometer. The standard deviation is less than 2 m/s. But when speed is between 20 m/s and 35 m/s, the wind speed of altimeter is close to the radiometer. Only the scanning microwave radiometer can be able to detect the wind speed larger than 35 m/s. Before using it to measure the wind speed larger than 35 m/s, we have to assess the accuracy of measurement.
The first Chinese dynamic environment satellites HaiYang-2A(HY-2A) satellite was successfully launched on August 16, 2011, with a Ku-band microwave scatterometer which can provide wind vector information of global ocean surface. The research results for all launched scatterometer in the Amazon rainforest region by the global scientists showed the variance of scatterometer backscatter coefficient measurements was less than 0.15dB with the season. According to this results, the analysis on HY-2A microwave scatterometer measurement data of the Amazon rainforest region in 2012—2013 have been finished, the results showed that HY-2A satellite scatterometer measurement performance onboard in 2012-2013 is very stable, which is consistent with the international research results that seasonal variation characteristic of HY-2A scatterometer measurements in the Amazon rainforest is less than 0.15dB.
The microwave scatterometer onboard HY-2A Satellite mainly makes measurements of surface wind vectors over the global oceans. In order to ensure that the quality of wind vectors produced by ground application system software,the product must be validated to provide the basis for the quantitative application of the data product.This paper performs the validation of wind vectorsretrieved by HY-2A scatterometer using national centers for environmental prediction (NCEP )model data. The validation result suggests that the validationmethod cangive the precision of the overall wind vectors, and also can be used to analyze the precision characteristics relating with thescanningpencil-beam system and the scatterometer measurement mechanism.Meanwhile the validation can aid to identify the short-term anomaly of measuring performance.
HY-2 scatterometer is a spaceborne pencil-beam radar measuring the backscattering coefficient of ocean surface. Firstly, based on the description of the working mechanism and the principle of ocean surface wind retrieval from scatterometer data, quantitative analyses of some of the typhoons captured by HY-2 scatterometer in 2012 were carried out in this paper, that include location of the typhoon center, typhoon structure, path and the radius of maximum wind speed. Secondly, ocean surface wind field was overplayed on the meteorological cloud image acquired by FY-2E satellite to reveal the consistency of spatial structure of these two sources of data. Furthermore, ocean surface wind field from ASCAT was also used to make a contrast to the ocean surface wind field of HY-2 scatterometer. Multi-angle analysis has revealed the validity of ocean surface wind field observation and the advantages of typhoon monitoring by HY-2 scatterometer. Finally, the pros and cons of the HY-2 satellite microwave scatterometer were summarized, and the possible improvements of the HY-2 scatterometer were proposed in this paper.
Sea surface wind speed has a very important role in the transfer of kinetic energy in the ocean, and the exchange of the matter and energy in the air-sea surface. The HY-2 satellite altimeter provides sea surface height, significant wave height, sea surface wind speed. And the accuracy of the wind speed affects the users’ application. In this study, the two-parameter algorithm is used to get the wind speed from HY-2 satellite radar altimeter. The correctness of this algorithm is calculated using the Jason-1 and HY-2 scatterometer data qualitatively. Three different methods(cross-over method, NDBC) are used respectively to evaluate this algorithm.
Significant wave height(SWH) is one of the important parameters which describe the sea state. The SWH derived from altimeter has been widely applied in marine research. Based on HY-2 altimeter waveform data, we develop an inversion algorithm of SWH with high-resolution. Using the RMSE condition to improve the accuracy 20 Hz SWH. Applied this method to one pass waveform data, the result shows the inversion algorithm is effective. Comparing the SWH derived from 1 s waveform, the SWH derived by this method could be increased by about 15 times the spatial and temporal resolution observations and the accuracy is about 0.44 m. The SWH derived from HY-2 altimeter 20 Hz waveform is reliable and could be applied for high resolution marine research.
Accuracy Satellite Scanning Microwave Radiometer ocean parameters retrieval need brightness temperature of multiple channel from same area and identical resolution. Due to the limitation of spaceborne radiometer antenna design and feedhorn arrangement, each channel has different resolution and observation position, this will increase the ocean parameter retrieval error. Based on the HY-2 Scanning microwave radiometer antenna pattern and imaging geometry, we simulate the ground footprint form different channel, use Backu-Gilbert(BG) algorithm produce a single composite sample at a particular location and with a particular spatial weighting pattern from combination of the adjacent measurements, the low frequency 6.6GHz is set as the reference channel. The result showed that the matching with resolution decreasing could simulate the real instrument observation without introducing noise.
This paper established retrieval algorithm of sea surface temperature，sea surface wind speed，atmospheric water vapor content，atmospheric liquid water content and rain rate for the HY-2 scanning microwave radiometer using simulation data of radiation transfer equation. And then we used on-orbit data to retrieve these parameters. The validation of sea surface temperature，sea surface wind speed shows that the algorithm is feasible and reasonable，which can retrieve the atmospheric and ocean parameters，and the accuracy meets the requirement of the design indicators. Currently，the validation of other parameters is still going on. The retrieval algorithm will be optimized by further calibration of brightness temperature.
The HY-2A satellite, launched on October 16, 2011 is the first dynamic environments satellite in China, carrying the DORIS tracking system which is one of main technology of precise orbit determination .The method and technological process of DORIS solution of HY-2A POD is introduced in detail, then the strategy of POD system is showed, finally the result of the MOE radial accuracy for DORIS solution of HY-2A satellite is given in this paper.
The HY-2A satellite, launched on October 16, 2011 is the first dynamic environments satellite in China, carrying the SLR tracking system which serve as the baseline tracking system, and in the meantime is one of technology of precise orbit determination. The measurement statistics of HY-2A satellite for the SLR stations, the orbit prediction, and the technological of SLR solution of HY-2A POD are showed, finally the result of the MOE radial accuracy verification for SLR solution of HY-2A satellite is given in this paper.
The GPS data acquired by the HY-2A satellite GPS receiver have been used in a dynamic orbit determination, which was based on the description of the gravitational and nongravitational forces in the equations of motion. The GPS carrier data were processed in a difference mode to remove clock errors. Simultaneous estimation of the HY-2 satellite orbit and GPS orbit was performed using the data in March (2012). The resulting HY-2 satellite orbits have been compared with CNES orbits and reduced dynamic orbits for GPS/DORIS/SLR strategies, and in the meantime confirmed with SLR validation. The radical component of the GPS orbit was found to agree with better than 3 cm.
Satellite altimeter was widely used in ocean monitoring and research, in order to find out the actual performance of the altimeter and access the accuratesea level data, we need to calibration. GPS buoys was mainstream devices in altimeter absolute calibration. Through simulation and experiment about the self-developed GPS buoy, this paperstudied the precision of GPS bouy and factors affecting.The results show that the self-developed GPS GPS buoy elevation measurement precision can reach 1 cm, meet the altimeter sea surface height calibration requirements.
GPS buoy is the important instrument for the calibration of altimeter sea surface height. This paper introduces the composition and operating principle of GPS buoy, and describes in detail the design of shape, cabin, leak-proofness, and current supply. And finally used the numerical simulation, the rock and undulation of GPS buoy were experimented in the 3 class sea state condition. The result shows that designed GPS buoy can meet the challenge of altimeter sea surface height calibration on the sea experiment condition.