Changes

Mookodi (spectrograph and imager)

3,000 bytes added, 14:10, 17 November 2021
/* Documentation */
== Project Team ==
'''Instrument PI:''' Iain Steele (LJMU; I.A.Steele@ljmu.ac.uk)
'''Instrument ScientistScientists:''' Helen Jermak (h.e.jermak@ljmu.ac.uk)/ Andrjez Piascik (LJMU; A.S.Piascik@ljmu.ac.uk)
'''SPRAT ExpertMechanical Engineer:''' Andrzej Piascik Stuart Bates (LJMU; S.D.Bates@ljmu.ac.uk)
'''Software Engineer:''' Chris Mottram (LJMU; C.Mottram@ljmu.ac.uk)
'''Local Co-PIsData Pipeline:''' Amanda Sickafoose & Hannah WortersMarco Lam (LJMU; C.Y.Lam@ljmu.ac.uk)
'''Local Electronics EngineerProject Scientist for LT:''' Hitesh GajjarRobert Smith
'''Local Mechanical EngineesrCo-PIs:'''James O'Connor and Egan LoubserNicolas Erasmus (nerasmus@saao.ac.za) & Hannah Worters (hannah@saao.ac.za)
'''Local Electronics Engineer:''' Hitesh Gajjar (hitesh@saao.ac.za) '''Local Mechanical Engineers:'''James O'Connor (joc@saao.ac.za), Egan Loubser (egan@saao.ac.za), and Kathryn Rosie (krosie@saao.ac.za) '''Local Software Engineer:''' Carel van Gend(carel@saao.ac.za)
== Documentation ==
* The link to the 2017 October 27 Skype kick-off presentation: https://www.dropbox.com/s/lcr54nkvtusdh69/SAAO-SPRAT-KICKOFF.pptx?dl=0 (includes references to the SPIE paper and Zej's thesis)
== Points to consider (based on 27 Oct. Skype) ==*(1) Hannah [[Media:Mookodi_System_Description_0.4.pdf|Mookodi System Description v0.4]] -- This document is to send Iain telescope optical prescription (done).*(2) Consideration provide a system description of mountingMookodi, in terms its sub-assemblies, locations of peripherals adjustments and control equipment — basically starting to think about packaging and how much needs to be mounted on the port vsreasons behind some of the decisions. off to It does not cover control software, nor procedures for setting up or testing the sides, note that control of moving parts will be pneumatic (James/Egan)instrument<!-- *(3) Question of which coating [[Media:Mookodi_Filter_Change_Instruct_0.2|Mookodi Filter Change Instructions v0.2]] -- This document describes the procedure to buy for fit/replace filters in the Andor iDus camera filter assembly. -- new option has higher QE over wider range> == Notes from meetings ==[[ 18 Nov. 2019]] [[ 01 Feb 2019]] [[ 27 Oct. 2018]] [[ 24 Jan. 2019]] [[ 31 Jan. 2019 Telecon with Iain, but higher dark current (Amanda & Hannah)plus email communication]] *[[ 12 Feb. 2020 Filter requirement meeting (4) Question of whether we want two optimized wavelength settingsNic, like SPRAT, or only one — the former aren’t being well used on SPRAT and the latter saves a moving part. although they say that they have plans to ensure that part is more reliable than the current version (Amanda & Hannah)*(5) Think about optimal slit size — 1.5” min, could be up to 2”Retha, could also consider stepped slit — these are laser cutJames, and we could request more than one (Amanda & HannahKathryn))]]*([[6) Thinking about Mar. 2020]] [[20 Mar.fits header information for compatibility with data reduction pipeline, and how to integrate TCS with instrument to allow automated acquisition (Carel)2020]] [[3 Apr 2020]] [[19 June 2020]] [[3 July 2020]] [[17 July 2020]] [[6 Nov 2020]]
== SHOC/SPRAT hybrid ==
Some more details [[50mmLensTest]]
 
* Point raised by Stu at 12 Feb. 2019 Skype about filter wheel insertion into collimated beam causing flexture. James thinks that if the design can stay within the original structure envelope, and we are smart about orientation, the current stiffness might suffice. Alternatives to consider are (1) mounting a filter wheel near the entrance to the instrument or (2) separate SPRAT/SHOC mountings, by removing SPRAT and disconnecting the camera to reattach on the port.
== Spreadsheet of pros/cons for proposed mounting options ==
[[File:LesediSpec.Mounting1.jpg||1000 px|center]]
 
== Project Schedule ==
Proposed: start 01 Jan 2019, delivery 04 May 2020. See timeline in bid. Note that paperwork was not signed until 01 March 2019, so there is an anticipated delay.
[[File:Screen Shot 2019-11-18 at 11.48.27.jpg||500px|center]]
 
== Lens Coatings and Andor CCD ==
17 July 2020: [[:File:Mookodi_iKon_test.pdf|Mookodi Andor camera test datasheet]]
 
17 January 2020: Decision was made to go with Andor Ixon 888 UVB and -AB AR coating for lenses. Decision swayed by the off-the-shelf Nikon lens which will be the limiting element for obtaining spectra/photometry below 400nm. -A coating not good > 750nm where other elements still perform well.
[[File:Lens_coatings_update.png||500px|center]]
 
== Preliminary Exposure Time Calculator ==
[https://livtel.github.io/saao_sprat_etc/ Calculator]
 
== Imaging Photometry Filters ==
Link below to the SDSS filters for Mookodi's imager:
 
* [[ Filter Plots and Data]]
 
== Camera ==
Link below to the Andor CCD spec sheet and manufacturer's performance sheet:
 
* [[Media:Andor iKon-M 934 Specifications.pdf]]
* [[File:Mookodi iKon test.pdf]]
 
== Interfaces ==
27 January 2020: Diagram showing overview of system interfaces.
[[File:LJMU_interfaces.png||1250px|center]]
 
== Software ==
 
 
[https://docs.google.com/document/d/1Z9aPGZ-iYJSIZjTwoWAixtsYDBt-WyQUKkqTMmgFrSc/edit Use case 1 - Sidereal Spectroscopy]
 
The software runs on an instrument PC, which hosts the camera driver software and connects to an Arduino for the moving parts. Additionally a filter mechanism may be controlled from here.
 
We envisage providing Thrift interfaces to the camera driver, the Arduino driver and the filterwheel driver. These all run as standalone server processes, and are accessed by an instrument controller process, which has clients for each of the server processes. The instrument controller contains logic to coordinate the instrument operations, and also is able to send commands to and receive state from the telescope.
 
The following diagram illustrates the software layout:
 
[[File:SpratBlocks.svg|1250px]]
 
=== Software Interfaces ===
 
==== Detector ====
 
==== Moving parts ====
 
=== Data Files ===
 
The camera driver software retrieves the observation data from the camera, converted this to FITS format and saves this to disk.
 
The FITS files are named according to the SAAO file naming convention:
 
==== FITS header fields ====
 
The FITS headers include the keywords:
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