空间科学学报

2006 Vol. 26, No. 4

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Dependences of Postnoon Auroral Intensity on Solar Wind-Magnetosphere Coupling Functions

HU Hongqiao, LIU Ruiyuan, YANG Huigen, N. Sato, M. Kikuchi

2006, 26(4): 241-249. doi: 10.11728/cjss2006.04.241

Abstract(2774) PDF 3405KB(1147)

Abstract:
Using auroral observations at Zhongshan Station, Antarctica with a multi-channels scanning photometer, and Interplanetary Magnetic Field （IMF） and solar wind parameters observed by Wind Satellite at the upstream of the bow shock in 1997 and 1998, the dependences of the highlatitude postnoon auroral intensity upon solar wind-magnetosphere coupling functions are studied quantificationally. It shows that the intensity of the postnoon 630 nm emission is highly dependent on the solar wind electric field and the solar wind energy density flux, the postnoon auroral emission has larger correlation coefficients with the solar wind electric field functions than with the solar wind energy density flux functions, which is consistent with Liou＇s result derived from images acquired by the ultraviolet imager on board Polar satellite. The dependences of 630 nm emission on the different solar wind electric field functions related to the clock angle are varied, which implies that the clock angle of the interplanetary field is also a very important factor on postnoon aurora. The dependencesof the postnoon auroral emission on solar wind-magnetosphere coupling functions and trans-polar potential functions are also studied. The intensity of the 630 nm emission depends on these functions more directly than that of the 557.7 nm emission.

The Temporal Variation Characteristics of OI5577 Airglow Intensity and Peak Density of Atomic Oxygen in 2000 and 2001 at 52°N

GAO Hong, XU Jiyao, YUAN Wei

2006, 26(4): 250-256. doi: 10.11728/cjss2006.04.250

Abstract(3661) PDF 2535KB(963)

Abstract:
The nocturnal variation and seasonal variation characteristics of OI5577 airglow intensity in 2000 and 2001 at 52°N are analyzed. By using the method of inversing atomic oxygen peak density from OI5577 intensity, the peak density of atomic oxygen is obtained. The nocturnal variation and seasonal variation characteristics of atomic oxygen peak density are discussed. The results show that the nocturnal variation characteristics of OI5577 airglow intensity change with seasons. In 2000, thepeak intensity appears after 0000 LT in spring, appears at 0000 LT in winter, and appears before 0000LT in summer and autumn. In 2001, the peak intensity appears before 0000LT in spring and autumn, and appears at 0000 LT in summer and winter. There are peaks of 015577 airglow intensity in February, August and October in 2000. In 2001, there is a peak of 015577 airglow intensity in September. As far as the main features are concerned, the nocturnal variation and seasonal variation characteristics of atomic oxygen peak density are consistent with those of 015577 airglow intensity.

The Suppression of Triangle Size Effect in Spaced Antenna Wind Measurements

SHU Weiping, ZHAO Zhengyu

2006, 26(4): 257-263. doi: 10.11728/cjss2006.04.257

Abstract(2702) PDF 377KB(1692)

Abstract:
There is the Triangle Size Effect （TSE） in wind measurements with Spaced Antenna （SA） method due to electronic noise and ground clutters etc. Another possible cause （non-stationary of atmosphere） of TSE and the mechanism of its effect to wind measurements was discussed in this paper. The work also presents Increment＇s Cumulant Approach （ICA） to eliminate the nontationary of atmosphere and ground clutter based on the analysis of the causes of TSE; the analytical expression of one dimension mean velocity can also be obtained by the special case of Increment＇s Cumulant Approach （the 2nd order zero-lags ICA）. In addition the high order （k ≥ 3） cumulant of increment are proposed to suppress Gaussian noise. The comparisons between FCA and ICA with non-stationary and ground clutter by numerical simulations show that the measurement errors of ICA are much less than those of FCA by comparing mean horizontal velocities （output of simulations） and input velocities of mode.

Applications of Surface Plasmon Resonance Biosensor in Microbial Detection

LIU Xueyong, BAI Yanqiang, XIONG Jianghui, WANG Chunyan, LI Yinghui

2006, 26(4): 264-267. doi: 10.11728/cjss2006.04.264

Abstract(3197) PDF 817KB(1176)

Abstract:
There are a variety of microbes in the environment of the Earth and spaceflight. The proliferation of these microbes especially the pathogenetic microbes in the spacecraft will threaten astronauts＇ health even lives, so rapid and accurate detection of these microorganisms is put on schedule. Among so many detection methods, surface plasmon resonance biosensor developed rapidly in recent years by merit of its rapidness and high sensitivity. The SPR phenomenon occurs when an incident beam of p-polarized light of a given wavelength strikes the surface at a given angle through a prism, the biosensors based on SPR principle are used to monitor the changes of refractive index of ultrathin organic films at metal surfaces and are widely applied in the interaction of antigen-antibody, DNA-DNA and so on, but the harsh conditions of space bring forward more demands for the sensor. Because the detection of SPR sensor is independent of the gravity and it can resist the interference of electromagnetic, sound and so on, the SPR sensor has great advantages in the application of space. This article summarizes the application of SPR biosensor in the microbial detection, aiming at providing reference to microbial monitoring of earth and spaceflight.

Studies on the Design and Analysis of Regional Navigation Constellations

SHUAI Ping, QU Guangji, CHEN Zhonggui

2006, 26(4): 268-276. doi: 10.11728/cjss2006.04.268

Abstract(2581) PDF 3379KB(1604)

Abstract:
The navigation constellation design is involved in the optimization issues of many parameters. The goal of constellation design is to search a set of parameters and generate a navigation constellation using them. It is required that not only the optimal performance for the constellation needs to be the hest, but the cost of developing and maintaining the navigation satellite system is also low. Firstly, the indexes of evaluating constellation performance, algorithms of computing constellation availability and parameters of designing constellation are described in detail in this paper. There are three primary performance indexes examined, including the continued coverage, space distribution and redundancy. Secondly, as the navigation constellation design is a multi-objective optimization issue, the semi-analysis approach is presented simply in term of the practical engineering requirement. Only considering the central earth gravity, an ideal constellation can be designed from the aspect of geometry. The constellation parameters can be obtained synthetically and optimally in the case of meeting the constellation performance indexes. Therefore, four constellation schemes are generated optimally by using the approach. Finally, by analyzing the performance indexes and positioning simulation results respectively based on four schemes, it can be shown preliminarily that the semi-analysis approach and constellation schemes are feasible and rational.

Location Algorithm and Error Analysis for Earth Object Using TDOA, FDOA by Dual-Satellite and Aided Height Information

LIN Xueyuan, HE You, SHI Pei

2006, 26(4): 277-281. doi: 10.11728/cjss2006.04.277

Abstract(2830) PDF 1490KB(1177)

Abstract:
Determining the position of an object on Earth＇s surface has many applications, such as in navigation and in remote sensing. The location system generally consists of a number of spatially well separated receivers that capture the radiated or reflected signal from the object. The satellite positioning systems has the advantage of long-distance and wide coverage compared with ground positioning systems and airplane positioning systems. When satellite positioning systems locates an object on earth＇s surface, TDOA （Time Difference Of Arrival） measurements, but when there are relative motions between object and satellite, the FDOA （Frequency Difference Of Arrival） can also be measured. When the altitude from sea-level of object is known, WGS-84 ellipsoid earth model can be used as the precise location model. This paper puts forwards the location algorithm for emitter on Earth using the TDOA and FDOA measurements of two low-orbit satellite, and studies in detail this algorithm, at the same time provides the error distributions model of location accuracy.

Research on Orientation Determining With Single Geostationary Satellite

ZHENG Chong, HAN Hongwei, ZHOU Bozhao, WU Jie

2006, 26(4): 282-286. doi: 10.11728/cjss2006.04.282

Abstract(2661) PDF 333KB(977)

Abstract:
This paper presents a new method for orientation determining, which can determine the baseline＇s orientation with only one geostationary satellite. The method depends on the fact that the satellite can be considered to be stationary relative to the observer on the earth. Because of the nature of the satellite, the line-of-sight vector from observer to satellite is also invariable, Its azimuth can be obtained through the coordinates of the satellite and the observer. If the baseline is in motions, the difference carrier phase between the two antennas will be changed accordingly. According to the variety, the angle between the baseline vector and the line-of-sight can be figured out. Since the line-of-sight is known, the azimuth of the baseline vector can be obtained easily. In this paper the error of the method is analyzed by mathematical and emulational ways, It comes to a conclusion that the best precision of the orientation can be obtained when the baseline is perpendicular to the sight line of the satellite. At the end of this paper the experiment is accomplished with a Beidou satellite. The experiment result shows that the precision of the baseline＇s orientation could be better than 0.07° when the baseline length is about 0,827 meters long; So it is proved that the principle of orientation determining with single geostationary satellite is right and feasible.

Study for the Matchable Combinations of Galileo/GPS Carrier Phase Observations

YI Bingxin, CHANG Qing, ZHANG Qishan

2006, 26(4): 287-291. doi: 10.11728/cjss2006.04.287

Abstract(2643) PDF 589KB(1040)

Abstract:
This paper presents a comprehensive study of the inter-frequency matchable combinations of 4 Galileo carrier phase observations and GPS L2 carrier phase observation. A comprehensive definition of the combinations of Galileo/ GPS＇s carrier phase observations is given, and errors such as system errors and observation error are analyzed. At last matchable definition and matchable necessary and sufficient conditions of the combinations of Galileo/GPS carrier phase observations are presented.

Precision Analysis and Shape Adjustment of Inflatable Antenna

XU Yan, GUAN Fuling, GUAN Yu

2006, 26(4): 292-297. doi: 10.11728/cjss2006.04.292

Abstract(2339) PDF 2287KB(1187)

Abstract:
Inflatable antenna structures made of flexible membrane materials have many benefits over machine deployable antenna： low in mass and can be packaged into small volumes and are easy to control the deploy process. A kind of ground demonstration model of lenticular membrane antenna was designed in this paper, and nonlinear finite-element analyz model of inflatable structures is built. Precision analyses of inflatable reflector were conducted, and all important design parameters such as inflation pressure, membrane thickness, material characteristics and antenna focal length are investigated. The parametric study results were then used to design a 2-meter ground demonstration model of lenticular membrane antenna. The demonstration antenna reflector model was assembled by twelve gores from 0.18-mm-thick Mylar films. Gravity influence in the reflector was compared under three postures and one of them is chosen as final experiment posture. For this antenna structure, a new feasible shape adjustment measure was improved based on surface accuracy test of the membrane antenna reflector. Analysis and experiment results indicate that this method can improve the inflatable reflector precision effectively.

A Control Technique for Rendezvous and Docking Based on Helix-approach Orbit of Inspector Satellite

ZHAO Jiankang, DAI Jinhai

2006, 26(4): 298-302. doi: 10.11728/cjss2006.04.298

Abstract(2411) PDF 1406KB(1053)

Abstract:
For the control pattern of rendezvous and docking of spacecrafts, the impulse control method has been applied in common, but it deplete more energy. In this paper, the concept of helixapproach was firstly applied to the rendezvous and docking control of spacecrafts and the idea that by helix relative orbit the approach spacecrafts could rendezvous the aim spacecraft was proposed. First, the feedback form of law of control, which helps to realize helix-approach orbit, was educed with the Hill equtions. Then, the helix-approach orbit of Inspetor satellite in space circular fly-around relative orbit was fully studied,and the trait of helix-approach control was analysed, and stability of helixapproach control was explained, and fuel of wasting was estimated. Last, as a resut of simulations of return of Inspetor satellite in space circular relative orbit, figures of contorl acceleration and helixapproach orbit are shown, which the result of simulations indicates right stability, and it prove that the helix-approach relative orbit is not only feasible but also of fine characters.

Thermal Analysis of the Solar Array in the Lunar Orbit

LI Peng, CHENG Huier

2006, 26(4): 303-308. doi: 10.11728/cjss2006.04.303

Abstract(3413) PDF 2019KB(1383)

Abstract:
Lunar detection is the beginning of the deep space detection. The energy for the satellite running around the moon is provided by the power system of solar arrays. The lunar orbital environment has the direct effects on the operations of the solar arrays. The characteristics of the surface of the moon and of the lunar orbit have been analyzed. The research object is a rigid solar array in polar lunar orbit. The method to determine the external heat fluxes received by solar array has been shown detailedly on the basis of fully considering the packing factor and the solar cell conversion efficiency. The process of heat transfer in solar array is treated as 3-D anisotropic transient heat conduction problem without internal heat source. Grid division has been made in the solar array and the fully implicit discrete equations have been acquired. The numerical simulation of solar array in polar lunar orbit has been made and the periodic distributions of the external heat fluxes and the temperature of solar array have been obtained. Comparison between the numerical results in earth orbit and that in lunar orbit shows the characteristics of the periodic distribution for thermal parameters of the solar array in lunar orbit, which will provide powerful references for the design of the solar array and the whole lunar satellite.

Simulation of Radiometric Calibration of Spaceborne SAR by Amazon Rainforest

TAO Kun, ZHANG Yunhua, GUO Wei, YUN Risheng, KANG Xueyan

2006, 26(4): 309-314. doi: 10.11728/cjss2006.04.309

Abstract(3803) PDF 2221KB(1437)

Abstract:
Radiometric calibration is a powerful means to quantify the SAR （Synthetic Aperture Radar） system performance. Compared with that before launching, there is a considerable distortion of the antenna elevation pattern after the spaceborne SAR is in orbit, which will debase the quality of SAR images greatly. An accurate measurement of the antenna elevation pattern is an important aspect of spaceborne SAR radiometric calibration. The external calibration of distributed targets based on the uniform backscattering is an optimal choice to measure the double-way antenna elevation pattern. Amazon rainforest is the most stable, most uniform and flattest distribute external target in the world. With a backscattering almost independent of the incidence, Amazon rainforest is regarded as an ideal radiometric calibration site. However, because the SAR data sets collected by our own spaceborne SAR are still unavailable at present, the estimation of unknown parameters of SAR antenna pattern model based on the simulated spaceborne SAR power image has been investigated in this paper. A successful computer simulation of how to determine the antenna elevation pattern in orbit by simulated Amazon rainforest SAR power images has been made, which is significant for the radiometric calibration of spaceborne SAR in our country.

Bent Pipe Satellite Network System and Area Routing Method

YUAN Jiang, WANG Yu, MENG Xin

2006, 26(4): 315-320. doi: 10.11728/cjss2006.04.315

Abstract(3853) PDF 809KB(1399)

Abstract:
There are two kinds of architecture for the Satellite Network （SN）： On-Board Processing （OBP） and Bent-Pipe （BP）. Although OBP has been attracted more attention in the research area due to its performance advantage, BP is still used by some of the satellite systems for its low system cost. It is obvious that the incompatibility between BP systems may cause resource waste and thus sharing resource can help to cut down the system cost further. Therefore, a general SN routing method Area Routing （AR） is proposed. AR can provide not only shared source for different SN system but also network access for sky flying satellites. In this paper, the connection of the satellites is discussed, and the concept of connection analysis is introduced. By using the connection analysis and simulation tool, the best configuration of satellite connection for both coverage and accessibility is demonstrated.