Astrobiological Considerations for the Selection of the Geological Filters on the ExoMars PanCam Instrument
Astrobiological Considerations for the Selection of the Geological Filters on the ExoMars PanCam Instrument
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DOI：
10.1089/ast.2010.0517
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发表时间：
2010-11-01
期刊：
影响因子：
4.2
通讯作者：
Ward, John M.
中科院分区：
文献类型：
--
作者：
Cousins, Claire R.;Griffiths, Andrew D.;Ward, John M.
全景相机（PanCam）仪器将提供ExoMars漫游者周围环境的可见-近红外多光谱成像，以识别附近地形中的感兴趣区域。这种多光谱能力取决于12个预先选定的“地质”过滤器，这些过滤器被集成到两个广角相机中。最初由火星探路者团队的成像仪设计，用于检测氧化铁，尽管对火星矿物多样性的了解不断提高，但该基线滤波器组在随后的任务（火星探测漫游者，Beagle 2，Phoenix）中基本保持不变。因此，ExoMars PanCam的地质过滤器将重新设计，以适应ExoMars的天体生物学重点，其中水合矿物地形（过去液态水的证据）将是优先目标。在这里，我们对ExoMars PanCam的新滤波器波长进行了初步调查，并展示了在火星模拟岩石上进行的测试结果。设计了两个新的滤波器组：一个具有间隔50 nm的滤波器（“F1-12”），另一个利用基于水合矿物反射光谱的新型滤波器选择方法（“F2-12”）。这些新的过滤器组，沿着小猎犬2号过滤器组（目前是ExoMars PanCam的基线），测试了它们识别火星模拟岩石中含水矿物和生物特征的能力。滤波器组，具有不同程度的能力，检测到的矿物黄钾铁矾，乳白色二氧化硅，明矾石，绿脱石，和菱铁矿存在于这些岩石样品的光谱特征。然而，没有一套过滤器能够检测到生物垫结构和小的（
The Panoramic Camera (PanCam) instrument will provide visible-near IR multispectral imaging of the ExoMars rover's surroundings to identify regions of interest within the nearby terrain. This multispectral capability is dependant upon the 12 preselected "geological" filters that are integrated into two wide-angle cameras. First devised by the Imager for Mars Pathfinder team to detect iron oxides, this baseline filter set has remained largely unchanged for subsequent missions (Mars Exploration Rovers, Beagle 2, Phoenix) despite the advancing knowledge of the mineralogical diversity on Mars. Therefore, the geological filters for the ExoMars PanCam will be redesigned to accommodate the astrobiology focus of ExoMars, where hydrated mineral terrains (evidence of past liquid water) will be priority targets. Here, we conduct an initial investigation into new filter wavelengths for the ExoMars PanCam and present results from tests performed on Mars analog rocks. Two new filter sets were devised: one with filters spaced every 50nm ("F1-12") and another that utilizes a novel filter selection method based upon hydrated mineral reflectance spectra ("F2-12"). These new filter sets, along with the Beagle 2 filter set (currently the baseline for the ExoMars PanCam), were tested on their ability to identify hydrated minerals and biosignatures present in Mars analog rocks. The filter sets, with varying degrees of ability, detected the spectral features of minerals jarosite, opaline silica, alunite, nontronite, and siderite present in these rock samples. None of the filter sets, however, were able to detect fossilized biomat structures and small (