Data Acquisition for a 16 CCD Drift‐Scan Survey
| Autor: | Paolo De Coppi, C. N. Sabbey, Augustus Oemler |
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| Rok vydání: | 1998 |
| Předmět: | |
| Zdroj: | Publications of the Astronomical Society of the Pacific. 110:1067-1080 |
| ISSN: | 1538-3873 0004-6280 |
| Popis: | The QUEST (QUasar Equatorial Survey Team) collaboration is using an innovative 16 CCD mosaic camera at the prime focus of the 1 m Venezuelan Schmidt telescope to conduct a drift-scan survey of the equatorial sky (≈4000 deg2 with |b| > 25). The data products, which consist of UBV photometry to mB ≈ 21 and objective prism spectroscopy to mB ≈ 19, will have various applications in addition to producing a homogenous sample of ~104 quasars. In this paper we describe the online data system, which is responsible for controlling the camera, and acquiring and managing ≈30 GB of raw image data per night. The data system, designed to be highly scalable and cost effective (under $10,000), distributes the data I/O and processing in parallel across a cluster of commodity PC components. We currently use seven Pentium-class processors (75-133 MHz), interconnected with parallel Ethernet networks, running the QNX real-time, network-wide operating system. To ease the data handling, fast algorithms provide various levels of online analysis and data compression, including a new lossless compression scheme based on adaptive linear prediction. |
| Databáze: | OpenAIRE |
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