Data Acquisition for a 16 CCD Drift‐Scan Survey

Open Access
Publisher Website
Google Scholar
Abstract
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.

This publication has 18 references indexed in Scilit: