高分辨率成像光谱(HRIS)技术进展和在未来超光谱成像仪中的实现

由欧洲空间局(ESA)资助的高分辨率成像光谱仪(HRIS)技术研制计划,设计目标为机载实验演示模型,最近进展引起了其子系统相当成功的发展.HRIS设计为覆盖光谱范围:450nm～2350nm、高空间和光谱分辨率的推扫超光谱成像仪.具有近空间设计的主要实验设备为:TMA(3反射镜消像散系统)、前置光学器件、具有in—field光谱分离器的双光路光谱仪(Officine Galileo)、专用CMOS多路输出传输器(GEC Marconi IR,实验用的MA-TRA MSF的2—d SWIR CMT探测器、信号处理系统(DSS)、一些定标源(DLR+LSS)、和所有器件的测试系统.该文叙述了除前置光学系统以外的每个器件的重要研究结果和进一步发展的潜力,也草拟了机载实验仪器的下一阶段的任务,并简单描述了所设想的高海拔高度飞行器.作者希望该论文能够激励在专用目标领域的机载HRISS实验任务的用户,积极的响应将会支持ESA继续这一研究计划.在HRIS合同下的技术进展对ESA观测任务中的PRISM(Processes Research by anImaging Space Mission)是有益的.其结论是:一些取得进展的结果对于欧洲将来发展机载和星载超光谱成像仪打下了基础.另外,该文还叙述了目前的PRISM基线概念的简单调研.

高分辨率多光谱宽视场视网膜成像仪

本发明提供一种用于获取高分辨率宽视场多光谱视网膜图像的眼科仪器,它包括基底视网膜成像器。

Alpine grassland fPAR change over the Northern Tibetan Plateau from 2002 to 2011

In this study, two different methods including Digital Camera and Reference Panel （DCRP） and traditional in situ fPAR observation for measuring the in situ point fPAR of very short alpine grass vegetation were compared, and the Moderate Resolution Imaging Spectroradiometer （MODIS） fPAR products were evaluated and validated by in situ point data on the alpine grassland over the Northern Tibetan Plateau, which is sensitive to climate change and vulnerable to anthropogenic activities. Results showed that the MODIS alpine grassland fPAR product, examined by using DCRP, and traditional in situ fPAR observation had a significant relationship at the spatial and temporal scales. The decadal MODIS fPAR trend analysis showed that, average growing season fPAR increased by 1.2 × 10^-4 per year and in total increased 0.86% from 2002 to 2011 in alpine grassland, when most of the fPAR increments occurred in southeast and center of the Northern Tibetan Plateau, the alpine grassland tended to recover from degradation slightly. However, climatic factors have influenced the various alpine grassland vegetation fPAR over a period of 10 years; precipitation significantly affected the alpine meadow fPAR in the eastern region, whereas temperature considerably influenced the alpine desert steppe fPAR in the west region. These findings suggest that the regional heterogeneity in alpine grassland fPAR results from various environmental factors, except for vegetation characteristics, such as canopy structure and leaf area.

Modeling All-sky Global Solar Radiation Using MODIS Atmospheric Products:A Case Study in Qinghai-Tibet Plateau

The surface solar radiation(SSR) is of great importance to bio-chemical cycle and life activities.However,it is impossible to observe SSR directly over large areas especially for rugged surfaces such as the Qinghai-Tibet Plateau.This paper presented an improved parameterized model for predicting all-sky global solar radiation on rugged surfaces using Moderate Resolution Imaging Spectroradiometer(MODIS) atmospheric products and Digital Elevation Model(DEM).The global solar radiation was validated using 11 observations within the plateau.The correlation coefficients of daily data vary between 0.67-0.86,while those of the averages of 10-day data are between 0.79-0.97.The model indicates that the attenuation of SSR is mainly caused by cloud under cloudy sky,and terrain is an important factor influencing SSR over rugged surfaces under clear sky.A positive relationship can also be inferred between the SSR and slope.Compared with horizontal surfaces,the south-facing slope receives more radiation,followed by the west-and east-facing slopes with less SSR,and the SSR of the north-facing slope is the least.

Clipping Alters the Response of Biomass Production to Experimental Warming: A Case Study in an Alpine Meadow on the Tibetan Plateau, China

Predicting how human activity will influence the response of alpine grasslands to future warming has many uncertainties.In this study, a field experiment with controlled warming and clipping was conducted in an alpine meadow at three elevations（4313 m, 4513 m and 4693 m） in Northern Tibet to test the hypothesis that clipping would alter warming effect on biomass production.Open top chambers（OTCs） were used to increase temperature since July,2008 and the OTCs increased air temperature by approximately 0.9o C ~ 1.8o C during the growing in2012.Clipping was conducted three times one year during growing season and the aboveground parts of all live plants were clipped to approximately 0.01 m in height using scissors since 2009.Gross primary production（GPP） was calculated from the Moderate-Resolution Imaging Spectroradiometer GPP algorithm and aboveground plant production was estimated using the surface-measured normalized difference vegetation index in 2012.Warming decreased the GPP, aboveground biomass（AGB） and aboveground net primary production（ANPP） at all three elevations when clipping was not applied.In contrast, warming increased AGB at all three elevations, GPP at the two lower elevations and ANPP at the two higher elevations when clipping was applied.These findings show that clipping reduced the negative effect of warming on GPP, AGB and ANPP, suggesting that clipping may reduce the effect of climate warming on GPP, AGB and ANPP in alpine meadows on the Tibetan Plateau, and therefore, may be a viable strategy for mitigating the effects of climate change on grazing and animal husbandry on the Tibetan Plateau.

基于液晶可调变滤色器的光谱图像获取及颜色重建方法

基于液晶可调变滤色器(LCTF)的光谱成像系统具有光谱分辨率高、结构紧凑、控制灵活等特点。搭建了一套可见光波段的高分辨率LCTF光谱成像系统,对系统的光谱图像获取及彩色图像重建方法进行了研究;建立了系统的光谱及颜色重建模型;基于标准色卡及标准测色系统,对该系统的颜色复现效果进行了实验验证;实验结果表明,该LCTF光谱成像系统的彩色图像颜色复现精度达可到较小色差水平。

Geologic characteristics of the Chang'E-3 exploration region

We present topographic, geomorphologic and compositional characteristics of a l°×l° （-660 km2） region centered near the landing site of Chang＇E-3 using the highest spatial resolution data available. We analyze the topography and slope using Digi- tal Terrain Model （DTM） generated from Terrain Camera （TC） images. The exploration region is overall relatively flat and the elevation difference is less than 300 m, and the slopes of 80% area are less than 5~. Impact craters in the exploration region are classified into four types based on their degradation states. We investigate the wrinkle ridges visible in the exploration region in detail using TC and Lunar Reconnaissance Orbiter （LRO） Narrow Angle Camera （NAC） images. We calculate FeO and TiO2 abundances using Multispectral Imager （MI） data, and confirm two basaltic units： the northern part belongs to Imbrian low-Ti/very-low-Ti mare basalts, and the southern part is Eratosthenian low-Ti/high-Ti mare basalts. Finally, we produce a ge- ological map and propose the geologic evolution of the exploration region. We also suggest several rover traverses to explore interesting targets and maximize the potential scientific output.

微小卫星在太空中闪烁(下)

其他欧洲机构的微小卫星计划欧洲航天局计划在2001年年中发射100千克重的PROBA卫星,用来研究小卫星技术。英国Sira光电公司于2000年8月交付了“小型高分辨率成像光谱仪”(CHRIS),以装入PROBA卫星中。CHRIS提供了覆盖0.415～1.05微米光谱段的160个光谱通道,每幅图像可选用其中60个光谱通道,覆盖13.5×13.5千米的面积,空间分辨率可达17米。该设备仅重14千克,功率9瓦,价格不到250万美元。