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--- wiki:observational_astronomy:observational_astronomy [2023/11/11 16:48] – Roy Prouty
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-====== Observational Astronomy ======
-===== Angles on the Sky =====
-Discuss degrees of arc, arc mins, arc secs.
-Discuss Altitude and Azimuth.
-Discuss hours or arc, minutes or arc, seconds of arc.
-Since a complete circle contains 24h of right ascension or 360° (degrees of arc), 1/24 of a circle is measured as 1h of right ascension, or 15°; 1/1440
-of a circle is measured as 1m of right ascension, or 15 minutes of arc (also written as 15′); and  1/86400 of a circle contains 1s of right ascension, or 15 seconds of arc (also written as 15″). A full circle, measured in right-ascension units, contains 24 × 60 × 60 = 86400s, or 24 × 60 = 1440m, or 24h. -- from wikipedia on RA
-Discuss Celestial Sphere. Discuss RA units, discuss DEC units.
-Discuss Hour Angle.
-Discuss how to determine an object's alt/az based on RA/DEC/Time/Lat/Lon.
-===== Focal Speeds/Ratios =====
-Discuss what is meant by the focal speed/ratio. What information does this convey?
-===== Telescope Limits =====
-==== Diffraction ====
-Discuss diffraction and Airy Disks
-Discuss Rayleigh Criterion & Dawes Limit
-==== Seeing ====
-Discuss what seeing is.
-Discuss how we measure seeing at UMBC Obs
-==== Magnitude ====
-Link to another wiki page about what a magnitude is.
-Discuss how scope can be magnitude limited.
-Discuss how to we measure our limiting magnitude.
-==== Guide ====
-Discuss what tracking/guiding is (no mentions of software).
-Discuss how poor tracking/guiding can cause limiting behavior in imaging.
-Discuss how we arrive at best tracking/guiding rates.
-==== Focus ====
-Discuss what focus is.
-Discuss how poor focus can cause limiting behavior in imaging.
-Discuss how we arrive at best focus.
-===== Sky Brightness =====
-Discuss origins/sources of sky brightness.
-Discuss how we measure sky brightness.
-===== Imaging =====
-===== Pixels and Angular Resolution=====
-(All without any mention of our specific cameras)
-Discuss what is meant by Plate Scale.
-Discuss pixel dimensions on detector and how to determine ideal angular resolution.
-Discuss detector sizes and how to determine FOV.
-==== Sampling ====
-===== Science Images =====
-A //science image// or //science frame// is a light frame that has been calibrated to account for optical system and detector contributions or non-uniformities as well as to the top-of-atmosphere. For us, a science frame is a frame whose counts have been calibrated such that all of the counts present in the frame are thought to be proportional to the amount of spectral energy received from the source over the integration time if there were no atmosphere. It is from these frames that you can estimate most physical quantities.\\ \\
-Though they are often necessary, the [[wiki:observational_astronomy:science_image|generation of a science image]] for our purposes does not include astrometric calibration.
-===== Gain =====
-Discuss what the gain is and what it does to the CMOS/ADC/Counts.
-===== Brightness =====
-Discuss what Brightness or post-flash is.
-===== Measurements =====
-[[wiki:observational_astronomy:measurements:Flux]]
-[[wiki:observational_astronomy:measurements:What the Detector Measures]]
-[[wiki:observational_astronomy:measurements:Magnitudes]]
-----
-Sources
-  - http://www.vikdhillon.staff.shef.ac.uk/teaching/phy217/instruments/phy217_inst_photcal.html
-  - https://www.baader-planetarium.com/en/blog/gain-and-offset-darks-flats-and-bias-at-cooled-cmos-cameras/
-  - https://www.nottingham.ac.uk/astronomy/observatory/reduction_guide.pdf
-  - https://owd.tcnj.edu/~pfeiffer/AST261/AST261Chap11,Phot.pdf
-  - https://ethz.ch/content/dam/ethz/special-interest/phys/particle-physics/quanz-group-dam/documents-old-s-and-p/Courses/vp-asl-astro/tortorelli_data_reduction_steps.pdf
-  - https://image-analysis.readthedocs.io/en/latest/index.html
-  - https://www.cse.wustl.edu/~jain/cse567-11/ftp/imgsens/
-  - https://en.wikipedia.org/wiki/Depletion_region
-  - https://www.photonics.com/Articles/Photon-Counting_CMOS_Sensors_Extend_Frontiers_in/a67740
-  - https://www.mssl.ucl.ac.uk/www_detector/ccdgroup/optheory/ccdoperation.html
-  - https://www.princetoninstruments.com/products/cosmos-family/cosmos/app-notes/advanced-cmos-detectors-for-astronomy
-  - https://starlink.eao.hawaii.edu/docs/sc5.htx/sc5se4.html#:~:text=The%20CCD%20is%20placed%20in,stored%20for%20later%20read%2Dout.
-  - https://physicsworld.com/a/advanced-cmos-detectors-enable-next-generation-astronomy/
-  - https://electronics.stackexchange.com/questions/686472/how-does-a-cmos-image-sensor-manage-to-read-and-record-all-the-pixel-values-any
-  - https://www.brown.edu/research/labs/mittleman/sites/brown.edu.research.labs.mittleman/files/uploads/lecture04.pdf