(Abridged) Typically large telescope construction and operation costs scale up faster than their collecting area. This slows scientific progress, making it expensive and complicated to increase telescope size. A metric that represents the capability of an imaging survey telescopes, and that captures a wide range of science objectives, is the telescope grasp -- the amount of volume of space in which a standard candle is detectable per unit time. We provide an analytic expression for the grasp, and also show that in the background-dominated noise limit, the optimal exposure time is three times the dead time. We introduce a related metric we call the information-content grasp, which summarizes the variance of all sources observed by the telescope per unit time. For seeing-dominated sky surveys, in terms of grasp, etendue, or collecting-area optimization, recent technological advancements make it more cost effective to construct multiple small telescopes rather than a single large telescope with a similar grasp or etendue. Among these key advancements are the availability of large-format back-side illuminated CMOS detectors with 1m) visible-light telescopes which are seeing-dominated, will be weakened. These ideas have led to the concept of the, currently under construction, Large-Array Survey Telescope (LAST).

中文翻译：

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视野受限的成像巡天——小型望远镜与大型望远镜

（删节）通常大型望远镜的建造和运营成本比它们的收集区域增长得更快。这减缓了科学进步，使增加望远镜尺寸变得昂贵和复杂。代表成像勘测望远镜能力并捕获广泛科学目标的指标是望远镜抓地力——单位时间内可检测到标准烛光的空间量。我们为抓取提供了一个解析表达式，并且还表明在背景主导的噪声限制下，最佳曝光时间是死区时间的三倍。我们引入了一个相关的度量，我们称之为信息内容掌握，它总结了单位时间内望远镜观测到的所有源的方差。对于以视见为主的天空调查，在抓地力、扩展度方面，或收集区域优化，最近的技术进步使得构建多个小型望远镜比具有类似抓地力或扩展度的单个大型望远镜更具成本效益。在这些关键进步中，具有 1m) 可见光望远镜的大幅面背照式 CMOS 探测器的可用性将被削弱。这些想法导致了目前正在建设中的大阵列巡天望远镜 (LAST) 的概念。