Owl Calibration 2017

[lah]

This ticket records the results from the Owl wavelength calibration in 2017. This is the first time this has been attempted and the scripts used are still experimental/ not yet reviewed, but a record is still very useful.

Data location: /users/rsg/arsf/arsf_data/2017/misc/Owl_post_BB_cal_Apr/Raw/19.04.17/wavelength

The process uses the raw data to calculate a transmission spectrum which is then compared to that measured by FSF instruments (a wiki page has been prepared in /users/rsg/arsf/scratch_space/wiki_text_DELETE_AFTER_BECOMES_LIVE/Owl_Wavelength_Calibration.docx).

This ticket also records the first attempt at comparing the radiometric stability of the Owl over a year, with a percentage difference plot included in the data quality report. The process is documented in: /users/rsg/arsf/scratch_space/wiki_text_DELETE_AFTER_BECOMES_LIVE/Owl_Radiometric_Calibration.docx

[lah]

The script used (and developed) is: calc_owl_wavelength_offset.py in the owl subdirectory of libarsfcal

[lah]

Multiple files were collected at different integration times, but there are only 2 complete measurements of the same sample. The commands used were:

calc_owl_wavelength_offset.py -r /users/rsg/arsf/arsf_data/2017/misc/Owl_post_BB_cal_Apr/Raw/19.04.17/wavelength/Wavelength_80_Ref_Int1_00_2017-04-19_13-38-30/capture/Wavelength_80_Ref_Int1_00_2017-04-19_13-38-30.raw -s /users/rsg/arsf/arsf_data/2017/misc/Owl_post_BB_cal_Apr/Raw/19.04.17/wavelength/Wavelength_80_PP_Filter_Int1_00_2017-04-19_13-48-37/capture/Wavelength_80_PP_Filter_Int1_00_2017-04-19_13-48-37.raw -c /users/rsg/arsf/arsf_data/2017/misc/Owl_post_BB_cal_Apr/Raw/19.04.17/wavelength/Wavelength_80_Black_Int1_00_2017-04-19_13-51-16/capture/Wavelength_80_Black_Int1_00_2017-04-19_13-51-16.raw -e -t /users/rsg/arsf/arsf_data/2017/misc/Owl_post_BB_cal_Apr/Docs/plasticTruthFSF.txt -o ~/scratch_network/transfer/Ttests/

calc_owl_wavelength_offset.py -r /users/rsg/arsf/arsf_data/2017/misc/Owl_post_BB_cal_Apr/Raw/19.04.17/wavelength/Wavelength_80_Ref_Int1_10_2017-04-19_14-06-48/capture/Wavelength_80_Ref_Int1_10_2017-04-19_14-06-48.raw -s /users/rsg/arsf/arsf_data/2017/misc/Owl_post_BB_cal_Apr/Raw/19.04.17/wavelength/Wavelength_80_PPsample_Int1_10_2017-04-19_14-08-46/capture/Wavelength_80_PPsample_Int1_10_2017-04-19_14-08-46.raw -c /users/rsg/arsf/arsf_data/2017/misc/Owl_post_BB_cal_Apr/Raw/19.04.17/wavelength/Wavelength_80_Black_Int1_10_2017-04-19_14-10-38/capture/Wavelength_80_Black_Int1_10_2017-04-19_14-10-38.raw -e -t /users/rsg/arsf/arsf_data/2017/misc/Owl_post_BB_cal_Apr/Docs/plasticTruthFSF.txt -o ~/scratch_network/transfer/Ttests/

[lah]

The results were:
PP_Filter: rms = 0.024, offset 6.836 nm
PPsample: rms = 0.027, offset 0.610 nm

Given the difference between the 2 measurements the offset measurement is not conclusive.

Manual inspection of the peak values suggests that fityk is correctly identifying the peaks and that the algorithm is working properly, so the difference may just be due to the spectral resolution of the Owl (50 nm).

More measurements should be taken in future for comparison, but with such small values compared to the spectral resolution, the wavelength shift is not currently of major concern.

[lah]

The output files have been stored here: /users/rsg/arsf/arsf_data/2017/misc/Owl_post_BB_cal_Apr/Processed/wavelength_transmittance

[lah]

The merge request for the script is ​https://gitlab.rsg.pml.ac.uk/arsf/libarsfcal/merge_requests/13

[lah]

script merged under version 1.0.2