云南天文台Hα全日面望远镜4K×4K CCD性能测试

An Evaluation of the Performance of the 4K×4K CCD on the YNAO Full-Disk Hα Telescope for Solar Observations

天文观测采用的CCD一般都要进行性能测试,然后再投入常规观测。针对云南天文台Hα全日面望远镜新引入的4 K×4 K大尺寸QHY16803 CCD已投入实际观测的情况,对其进行了较为全面的测试,检测内容包括有效尺寸、本底情况、读出噪声、增益、暗流、热像素等等。从检测结果来看,该CCD是适用于太阳全日面观测的。同时提出的检测方案是一种在非实验室条件下的测试方案,较为方便和快捷。从检测结果来看,参数的测量可信度高。

The performance of a CCD device is very important for astronomical observations using the CCD. Usually,a CCD device is tested in a laboratory before being mounted on a telescope. However,in our case,the 4K × 4K CCD device used for the YNAO( Yunnan Observatory) full-disk Hα telescope for solar observations has to be evaluated during routine observations. Therefore,we have developed a special test program and we show the test results in this paper. The best active area of the CCD is between( 140,128) and( 4035,4023); its bias level is around 670 ADU and its read-noise is about 13. 5e-. The dark current of the CCD is about 0. 5e-/ second at- 10℃. The dark-current level is higher than the specification of the manufacturer( KADAK),but it is low enough for observations. From the evaluation results we confirm the feasibility and reliability of our test approach. This approach can also be used to monitor changes of CCD parameters during routine observations,which can incorporate such tests.