Physics projects for Y3 and Y4 students

Project description

Calibration of imaging detectors

(supervisor: Matt Gunn)

Nature of project: experimental, data analysis

Available to students on full-time physics degree schemes or joint students.

Project description and methodology

Imaging detectors are now included in a huge variety of electronic devices. The majority of these are intended only to capture visually pleasing images but in some cases they are used as scientific measuring instruments. In order to obtain a meaningful measurement from an imaging detector it must be calibrated to allow the raw output to be converted into a physical unit such as radiance or reflectance. Calibrating detectors involves characterising a number of detector properties including noise characteristics, linearity, conversion gain and full well capacity. These can be determined form a relatively simple set of measurements using the photon transfer technique. CCD detector have very good linearity and so the applicator of the photon transfer technique is straightforward, whilst CMOS devices can exhibit significant non-linearity which complicate the analysis.

In this project you will characterise an imaging detector or detectors using the photon transfer technique. You will capture the required measurements and analyse them to determine the detectors performance characteristics. If it is not possible to carry out the experimental aspects of the project for any reason then existing data will be provided.

A successful project will develop beyond the above in one/some of the following directions:
Initial characterisation will be performed in CCD detector for simplicity. I this is completed successfully then the additional complexity introduced by the non-linear behaviour of CMOS devices can be investigated.

When considering where to take your project, please bear in mind the time available. It is preferable to do fewer things well than to try many and not get conclusive results on any of them. However, sometimes it is useful to have a couple of strands of investigation in parallel to work on in case delays occur.

Additional scope or challenge if taken as a Year-4 project: Extensive calibration data has been collected from the cameras in the ExoMars PanCam instrument as part of the pre-flight calibration campaign. 4th year students will get the opportunity to analyse the PanCam calibration data and contribute to the preparation work for the ExoMars surface mission.

Please speak to Matt Gunn (mmg) if you consider doing this project.

Initial literature for students:

  1. Janesick, James R. Photon transfer DN→ λ. 2007.
  2. Janesick, James, James T. Andrews, and Tom Elliott. "Fundamental performance differences between CMOS and CCD imagers: Part 1." High Energy, Optical, and Infrared Detectors for Astronomy II. Vol. 6276. International Society for Optics and Photonics, 2006.
  3. Coates, A. J., et al. "The PanCam instrument for the ExoMars rover." Astrobiology 17.6-7 (2017): 511-541.

Novelty, degree of difficulty and amount of assistance required

Some programming skills will be required to carry out the photon transfer analysis. An understanding of electronics / electrical systems will be highly beneficial.

Project milestones and deliverables (including timescale)

milestoneto be completed by
Project outlineend of November
Initial measurements and analysisend of February
Detailed measurements and analysis underwaymid-March
Complete measurements and data analysisEaster