Developing and Testing a Cooling System for CMOS in DSLR to Minimize Noise in Astronomical Image and Incorporating a Sky Quality Meter

Abstract

To capture faint astronomical images effectively, commercial camera like Digital Single-lens reflects (DSLR) require operation at low temperatures to minimize dark current noise. To achieve this, a cooling system utilizing Thermoelectric Cooler (TEC) technology is devised. This cooling apparatus is regulated by a microcontroller employing digital PID control. The design process for the cooler and its fan is conducted via computational fluid dynamics (CFD) simulations. Real-time temperature data is acquired using a temperature sensor affixed to the rear of the camera sensor. This data serves as input for the digital PID control algorithm, with the calculated PID results then applied to the PWM controller linked to the TEC. Consequently, the camera sensor temperature is effectively lowered in accordance with the specified target temperature. Apart from that, a sky quality meter is also installed on the device to measure the brightness of the night sky. By integrating the sky quality meter with the DSLR, researchers can obtain additional data in the form of sky brightness, which will be very useful in analyzing and interpreting astronomical images. In this paper, a DSLR camera cooling system integrated with a sky quality meter will be designed, tested and discussed in detail.