图 1：梦飞巡天望远镜焦平面；Focal plane of Mephisto

梦飞巡天望远镜将配备3台大靶面CCD拼接相机，每台由9216×9232的e2v CCD290-99芯片2×2拼接而成，像元大小10 μm，对应0.286′′（图 1）。3台相机总像素超过10亿，与LSST相当。为了优化观测效率，不同通道使用的芯片采用不同的镀膜技术，实现了从紫外到红光的高量子效率（QE）的宽光谱响应：蓝端相机采用标准硅芯片(增强UV0镀膜)，黄色相机采用标准硅芯片(Astro Multi-2镀膜)和红色相机采用深耗尽芯片（Astro Multi-2镀膜）。中国科学院国家天文台负责研制3台拼接相机，目前正在按计划推进，预计2025年初完成研制。

Mephisto will be equipped with three CCD cameras for the three channels. The focal plane assembly of each camera consists of a mosaic of four 9k by 9k science CCDs (Fig. 1, provided by e2v CCD290-99, with a pixel size of 10µm). The 10µm pixels subtend about 0.286′′ on the sky.  The fully functional Mephisto equipped with three cameras will perform imaging with over one gigapixels in total, a similar scale to the cameras of LSST. To optimize the observing efficiency, different coating techniques are employed for the chips used at different channels to realize a broad spectral response with high quantum efficiency (QE) from the ultraviolet to the red, as well as low interference fringing in the red: standard silicon chips (enhanced UV0 coating) for blue camera, standard silicon chips (Astro Multi-2 coating) for yellow camera and deep depletion chips (Astro Multi-2 coating) for red camera. National Astronomical Observatories, CAS is responsible for developing three mosaic CCD cameras, which are currently under progress as planned and expected to be completed in early 2025.

为尽早开展测试观测、先导巡天，产出科学数据，项目计划在望远镜调试及巡天初期采用三台Andor iKon-XXL单芯片科学级超大靶面CCD相机。每台Andor相机6144×6160像素（e2v CCD231-C6，像元大小15μm，对应0.429′′），其中：蓝端相机采用标准硅芯片(AL镀膜)，黄色相机采用标准硅芯片（BEX2镀膜） 而红色相机采用深耗尽芯片（BEX2镀膜）。望远镜现搭载两台Andor单芯片相机（覆盖1/4视场），每日开展光学调试和测试观测，具备较强的观测能力，产出有用观测数据并获得重要科学成果。

In order to generate scientific data as soon as possible, 3 Andor iKon-XXL CCD commercial   single-chip cameras during the commission phase and early stage of the project (within the first 1-2 years). Each Andor camera has 6144×6160 pixels (e2v CCD231-C6, with a pixel size of 15µm, corresponding to 0.429′′ on the sky), of which the blue camera uses a standard silicon chip (AL coating). The yellow and red camera uses a standard silicon chip (BEX2 coating) and a deep depletion chip (BEX2 coating). The telescope is currently equipped with two Andor single-chip cameras (covering 1/4 of the field of view), which are proven to have strong observation capabilities, generate valuable observation data, and achieve important scientific results.

为了降低立方棱镜带来的颜色效应，提升有效温度、金属丰度和重力加速度等参数敏感度，我们采用一个类似SkyMapper的滤光片系统，并通过调整滤光片中心波长和带宽以优化最终方案。

We adopt a filter system similar to SkyMapper survey, and optimize the final scheme by adjusting the central wavelength and bandwidth, allowing precise parameter determinations (Teff, log g, [Fe/H]) for stars and stellar populations and reducing  colour effect introduced from  cubic prisms to a greater extent.

图2. 梦飞巡天望远镜的滤光片参数；Filter parameters of Mephisto.