| Name: Supriyo Ghosh |
| Affiliation: University of Hertfordshire, UK |
| Conference ID: ASI2026_102 |
| Title: Enhancing the Dynamic Range of an sCMOS Astronomical Camera through Row-Readout Sequencing |
| Abstract Type: Poster |
| Abstract Category: Facilities, Technologies and Data science |
| Author(s) and Co-Author(s) with Affiliation: Supriyo Ghosh and collaborators(University of Hertfordshire, College Lane, Hatfield, Hertfordshire, AL109AB, UK) |
| Abstract: Dynamic range (DR) is a key parameter that determines the range between the brightest and faintest objects a sensor can detect. A high DR is particularly desirable for astronomical sensors. In recent years, scientific complementary metal-oxide-semiconductor (sCMOS) sensors have gained popularity due to their low cost and wide availability. However, current generations of sCMOS sensors are somewhat limited in their dynamic range. Consequently, exploring methods to enhance the DR of various sCMOS sensor models is of significant interest. In this study, our primary motivation was to enhance the dynamic range of a commercial CMOS sensor, the CIS120, while providing a comprehensive characterization of the sensor. CIS120 is specifically designed for space applications with extensive row readout flexibility and is capable of capturing spectroscopic data from X-ray to infrared wavelengths. We operated the detector in various modes, achieving a minimum dark current level of 0.002 e-/s at -50C. To enhance dynamic range, we implemented row-readout sequencing, in which the sensor’s rows are divided into two groups: one group is read out multiple times, while the other is read out only once to form the final image. We demonstrated our dynamical enhancement scheme in both laboratory and on-sky experiments. Laboratory results showed an improved dynamic range of -134 dB, up from the sensor’s native 12-bit (-72 dB) performance. For on-sky experiments, we observed Vega and Polaris fields, which contain both bright stars (with magnitudes around 0) and faint stars. Our scheme enabled us to detect stars as faint as 15th magnitude without saturating the bright stars near zero magnitude, corresponding to a dynamic range of approximately one million to one for a 12-bit astronomical camera. |
