共查询到20条相似文献,搜索用时 78 毫秒
1.
航天超光谱成像技术原理及其发展现状 总被引:2,自引:0,他引:2
介绍了国际航天超光谱成像仪的发展状况,简要分析了光栅型超光谱成像仪和干涉型超光谱成像仪的原理,并对我国发展航天超光谱成像遥感技术提出了建议。 相似文献
2.
3.
4.
5.
6.
超光谱成像仪的实验室定标 总被引:2,自引:0,他引:2
星载超光谱成像仪是一种空间调制型干涉光谱成像仪,文章研究了一套适用于干涉成像光谱仪、具有一定精度的实验室定标方法,满足了超光谱成像仪的实验室定标要求。采用激光光源进行光谱定标,光谱定标精度优于2nm。用远距点光源光路进行CCD探测器像元响应不均匀性修正,并进一步用天空背景光或均匀平行光进行全系统光能传输不均匀修正,实现了干涉图平场,相对定标精度达到2.46%。采用太阳模拟光源和均匀平行光路,用光谱辐射度计(ASD)实现标准辐射亮度的传递进行光谱辐射度定标,绝对定标精度达到8.21%。 相似文献
7.
基于光谱特性的高光谱图像压缩方案 总被引:5,自引:2,他引:3
根据干涉型高光谱成像仪成像特点,提出了一种针对干涉型光谱仪所获得高光谱图像的基于光谱特性的图像压缩方案。由于光谱信息最终从“点”十涉图像中恢复,因此方案中首先通过高精度匹配技术将原始“像面”干涉图像序列“重组”成“点”干涉图像,然后针对“点”干涉图像序列进行压缩。在重组过程中采取基于光流的亚像素级匹配和基于梯度的三角插值算法,实现了高精度的图像匹配重组;在压缩环节利用“点”干涉图像与光谱信息之间的傅立叶变换关系,提出一种能够很好保持频谱特性的基于一维DCT的压缩算法。实验证明,压缩算法总体性能远高于针对“像而”干涉圈序列的压缩算法.很好地控制了光谱信息的失真。 相似文献
8.
9.
10.
《航天器工程》2021,30(5)
高光谱成像仪以其纳米级光谱分辨率可同时获取地物的图像和光谱信息,辐射定标的精度是其定量化应用的关键环节,而偏航定标降低了对定标场地的选择要求,为高光谱成像仪在轨高频次定标提供了支撑。文章提出一种基于卫星平台90°偏航机动的高光谱成像仪在轨偏航定标方法,包括偏航数据的获取及数据处理、分析方法。基于资源一号02D卫星在轨数据对此方法进行了验证,结果表明:该方法对高光谱成像仪的相对辐射校正具有良好的效果,探测器所有像元相对辐射定标精度可达1%,原始图像中的条纹噪声得到很好去除。文章提出的方法可以实现高光谱成像仪的高频次、全视场相对辐射校正,为后续高光谱数据的定量化应用打下基础。 相似文献
11.
介绍了中国台湾研制的“中华卫星一号”(ROCSAT-1)实验卫星的概况。较详细介绍该卫星上的海洋水色成像仪的构成、主要性能。给出了“中华卫星一号”及其海洋水色成像仪外形图和结构图。 相似文献
12.
《中国航天(英文版)》2017,(2)
FY-4 is the second generation of Chinese geostationary satellite for quantitative remote sensing meteorological application. The detection efficiency, spectral bands, spatial and time resolution have been greatly improved with respect to those of first generation, as well as the radiometric calibration and sensitivity. The combination of multichannel detection and vertical sounding was first realized on FY-4, because both the Advanced Geostationary Radiation Imager(AGRI) and Geostationary Interferometric Infrared Sounder(GIIRS) are on the same spacecraft. The main performance of the payloads including AGRI, GIIRS and Lightning Mapping Imager, and the spacecraft bus are presented, the performance being equivalent to the level of the third generation meteorological satellites in Europe and USA. The acquiring methods of remote sensing data including multichannel and high precision quantitative observing, imaging collection of the ground and cloud, vertical observation of atmospheric temperature and moisture, lightning imaging observation and space environment detection are shown. Several innovative technologies including high accuracy rotation angle detection and scanning control, high precision calibration, micro vibration suppression, unified reference of platform and payload and on-orbit measurement, real-time image navigation and registration on-orbit were applied in FY-4. 相似文献
13.
《Acta Astronautica》2003,52(2-6):111-116
The Comet Nucleus Tour (CONTOUR) is a low-cost NASA Discovery mission designed to conduct three close flybys of comet nuclei. Selected configuration tradeoffs conducted to balance science requirements with low mission cost are reviewed. The tradeoffs discussed focus on the optical instruments and related spacecraft considerations. Two instruments are under development. The CONTOUR Forward Imager (CFI) is designed to perform optical navigation, moderate resolution nucleus/jet imaging, and imaging of faint molecular emission bands in the coma. The CONTOUR Remote Imager and Spectrometer (CRISP) is designed to obtain high-resolution multispectral images of the nucleus, conduct spectral mapping of the nucleus surface, and provide a backup optical navigation capability.Tradeoffs discussed are: (1) the impact on the optical instruments of not using reaction wheels on the spacecraft, (2) the improved performance and simplification gained by implementing a dedicated star tracker instead of including this function in CFI, (3) the improved flexibility and robustness of switching to a low frame rate tracker for CRISP, (4) the improved performance and simplification of replacing a visible imaging spectrometer by enhanced multispectral imaging in CRISP, and (5) the impact on spacecraft resources of these and other tradeoffs. 相似文献
14.
The first Korean multi-mission geostationary Earth orbit satellite, Communications, Ocean, and Meteorological Satellite (COMS) was launched by an Ariane 5 launch vehicle in June 26, 2010. The COMS satellite has three payloads including Ka-band communications, Geostationary Ocean Color Imager, and Meteorological Imager. Although the COMS spacecraft bus is based on the Astrium Eurostar 3000 series, it has only one solar array to the south panel because all of the imaging sensors are located on the north panel. In order to maintain the spacecraft attitude with 5 wheels and 7 thrusters, COMS should perform twice a day wheel off-loading thruster firing operations, which affect on the satellite orbit. COMS flight dynamics system provides the general on-station functions such as orbit determination, orbit prediction, event prediction, station-keeping maneuver planning, station-relocation maneuver planning, and fuel accounting. All orbit related functions in flight dynamics system consider the orbital perturbations due to wheel off-loading operations. There are some specific flight dynamics functions to operate the spacecraft bus such as wheel off-loading management, oscillator updating management, and on-station attitude reacquisition management. In this paper, the design and implementation of the COMS flight dynamics system is presented. An object oriented analysis and design methodology is applied to the flight dynamics system design. Programming language C# within Microsoft .NET framework is used for the implementation of COMS flight dynamics system on Windows based personal computer. 相似文献
15.
16.
《中国航天(英文版)》2017,(2)
Lightning is a typical example of an instantaneous random point source target. It has close connection with severe convective phenomena such as a thunderstorm, whose distribution, variation, position and forecasting can be acquired through lightning observation. In this paper, we discuss the way to achieve instantaneous lightning signal intensification and detection from geostationary orbit by using the differences between the lightning signal and the slowly changing background noise such as that of cloud, land and ocean, combining three methods, spectral filtering, spatial filtering and background noise, enabling removal between frames. After six months of operation in orbit, lightning within the coverage of the Geostationary Lightning Imager was effectively detected, strongly supporting the case for shorttime and real-time early warning, forecasting and tracking of severe convective phenomena in China. 相似文献
17.
Dust storms are meteorological phenomena of great interest for scientific community because of their potential impact on climate changes, for the risk that may pose to human health and due to other issues as desertification processes and reduction of the agricultural production. Satellite remote sensing, thanks to global coverage, high frequency of observation and low cost data, may highly contribute in monitoring these phenomena, provided that proper detection methods are used.In this work, the known Robust Satellite Techniques (RST) multitemporal approach, used for studying and monitoring several natural/environmental hazards, is tested on some important dust events affecting Mediterranean region in May 2004 and Arabian Peninsula in February 2008. To perform this study, data provided by the Spinning Enhanced Visible and Infrared Imager (SEVIRI) have been processed, comparing the generated dust maps to some independent satellite-based aerosol products. Outcomes of this work show that the RST technique can be profitably used for detecting dust outbreaks from space, providing information also about areas characterized by a different probability of dust presence. They encourage further improvements of this technique in view of its possible implementation in the framework of operational warning systems. 相似文献
18.
In this paper the detection of components of volcanic eruption has been carried out investigating, in appropriate bands of the electromagnetic spectrum (6.25, 8.7, 10.8, 12 μm), the values of the brightness temperature. The analysis has been performed in the Thermal Infrared Region (TIR) studying both the absorption–emission and scattering phenomena related to the interactions between electromagnetic radiation and volcanic emissions. The results have been achieved by means of a combined use of numerical simulations, devoted to examining the behaviour of the atmosphere gases and volcanic components, and remotely sensed satellite images. The proposed methodologies allow an estimate of the amount of gaseous and solid components, of the size of the emitted particles, of the height of the volcanic plume and of the distance of the volcanic components from the crater. The processed images come from the Spinning Enhanced Visible and InfraRed Imager (SEVIRI) sensor on board the geo-stationary satellite Meteosat Second Generation (MSG) and take into consideration an eruption of the Etna volcano as a study case (1st of April 2012, 04:30 and 05:30 UTC). The procedures are general and may therefore be extended to any other similar case. 相似文献
19.
As a result of processing long (up to 144 h) series of sunspot magnetograms obtained on the SOHO (Solar and Heliospheric Observatory) spacecraft with the MDI (Michelson Doppler Imager) instrument it is shown that the mode
with a period of 800–1300 min is a limiting low-frequency oscillation mode of the magnetic field of a sunspot as a whole.
Its period is essentially and nonlinearly depends on the sunspot magnetic field strength. In addition to this mode, higher
harmonics are also revealed in the sunspot oscillation spectra in the bands 40–45, 60–80, 135–170, 220–250, and 480–520 min.
The oscillation power in these bands monotonically and rapidly decreases with increasing frequency, which is characteristic
for overtones arising due to the nonlinear nature of oscillations. The limiting oscillation mode stably exists in sunspots
for 1.5–2 days, which coincides with the average lifetime of a supergranular cell. The mode with the period of 35–48 h observed
in the power spectrum is not an eigen mode of sunspots, because its period is independent of its magnetic field strength.
Probably, it occurs as a quasiperiod of an external exciting force caused by disturbances from supergranular cells surrounding
the sunspot. 相似文献
20.
蓝凤相 《运载火箭与返回技术》2007,28(1):54-57
文章论述了航天电子产品在工程设计过程中工艺设计的重要性,以及在产品设计中融入工艺设计概念后具体设计及相关内容。围绕设计、工艺、装联实践中的具体情况,提出了设计中应注意的问题。 相似文献