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371.
We describe a new BVRI multicolor CCD photometric system situated at the prime focus of the 85-cm telescope at the Xinglong Station of NAOC. Atmospheric extinction effects, photometric accuracy and color calibration dependence of the system are investigated. Additional attention was paid to giving observers guidance in estimating throughput, detection limit, signal-to-noise ratio and exposure time. 相似文献
372.
373.
Martin Bange Stefan Jordan Michael Biermann Thomas Kämpke Ralf-Dieter Scholz 《Experimental Astronomy》2002,13(2):101-117
We propose an object detection algorithm which is efficient and fast enough to be used in (almost) real time with the limited
computer capacities onboard satellites. For stars below the saturation limit of the CCD detectors it is based on a four neighbourhood
local maximum criterion in order to find the centre of a stellar image. For saturated stars it is based on the assumption
that the image is increasing monotonically towards the centre in the unsaturated part of the image. The algorithm also calculates
approximate stellar magnitudes and efficiently rejects most of the cosmics which would otherwise lead to a large number of
false detections. The quality of the algorithm was evaluated with the help of a large set of simulated data for the DIVA satellite
mission; different assumptions were made for the noise level, and the presence of cosmics or for a variable sky background.We
could show that our algorithm fulfills the requirements for DIVA; only in the case of simulated images which included the
bright galaxy M31 some fainter stars could not be detected in the galaxy's vicinity. Since stellar images contain large areas
without any stars, we propose an additional block-skipping algorithm which can be coded on special-purpose hardware.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
374.
赤潮藻的显微图形测量方法研究 总被引：2，自引：0，他引：2
介绍了一种在实验室环境下通过显微镜及CCD成像的办法观察采集微小藻类图像，并通过计算机软件进行图像识别统计，最终得到所测藻类统计信息的方法。 相似文献
375.
376.
We present details of one operational ground-based experiment for optical detection of GRBs and two which are under consideration/development. The wide-field CCD camera is already in manual burst alert operation with promising results. The Optical Transient Monitor is a CCD-based double monitor suitable for network use for reliable detection of short-lived phenomena in the sky. The system is well suited for correlated efforts with GRB projects. The third experiment is a robotic telescope with automatic response to GRB burst alert messages received via the Internet link. It is expected to get CCD frames with a FOV of 20 deg (needed for BACODINE triggers) of positions of newly detected GRBs within 1 minute. 相似文献
377.
美国国立光学天文台的IRAF软件系统,已成为国内光谱处理的主要计算机软件之一。由射电天文需要发展起来的FITS格式,已作为国际上交换磁带数据资料的通用格式。本文简单地介绍了FITS格式,讨论了如何将厚片CCD光谱观测资料转换为IRAF图像,继而转换为标准FITS格式。这对于使用IRAF系统进行光谱处理,以及国内国际间的资料交换是有用的。 相似文献
378.
379.
380.
线阵CCD推扫式影像的扩展核线模型 总被引：1，自引：0，他引：1
首先简要论述了框幅式中心投影遥感影像的传统核线模型及其理论特性,分析和总结了线阵CCD推扫式遥感影像的核线模型及其研究现状;其次通过与框幅式中心投影遥感影像核线模型的对比研究,利用投影轨迹法建立了一种既适用于框幅式中心投影遥感影像,又适合于线阵CCD推扫式遥感影像的扩展核线模型;最后通过实验总结分析了它的基本特性. 相似文献