Changes
SHOC
,/* Automated Data Acquisition (Scripting) */
Dr. Marissa Kotze has written some [http://shoc.saao.ac.za/Pipeline/ pipeline] software which may help with reduction of SHOC data.
===IMPORTANT NOTES===* '''IMPORTANT NOTES ABOUT THE NEW SOFTWARECONSIDER DECREASING DETECTOR TEMPERATURE IF TAKING LONG EXPOSURES''' Reports in 2016 indicated that the dark current is higher than expected (by a factor of ~ 100; more information to follow). This is most noticeable for long (>=10 minute) exposures. The camera is automatically cooled to -50C. It can be cooled down to -70 C; however, if the ambient temperature is high, the cooler will be stressed and cannot reach minimum temperatures. If you do adjust the temperature to -60, -65 or -70, please listen carefully so that if the temperature alarm triggers (a high-pitched, continuous beep) you can stop cooling and prevent hardware failure. March 2017* '''THE NEW SOFTWARE HAS DIFFERENT FILE NAMES AND HEADER KEYWORDS THAN PREVIOUS DATA.''' If you use this information in your analyses, you will have to update it. The filename format has been standardized to <Instrument>_YYYYMMDD.####.fits, where the instrument is sha (shocnawe), shd (shocndisbelief), or SHH to designate which SHOC box is being used. Please check the header of a new data file or the wiki [http://topswiki.saao.ac.za/index.php/SHOC#FITS_Header_Keywords FITS header keywords] (the "new" keywords are directly from the Andor iXon camera under Linux). March 2015* '''THE FILE SIZE IS NO LONGER LIMITED TO 2 GB. ''' This means that if you take large data cubes, the file size has ''no limit'' (this is because we are no longer on a Window-based, 32-bit, operating system). If you end up with a very large file, data analysis can be difficult. We are working on an efficient method to automatically split files into smaller sizes, but for now users need to be aware that requesting a large number of images in one file could return a very large file size (and if you mistakenly delete your file, you have lost alot of work!). It is recommended that multiple files be manually taken. ''If you have any questions or problems with the data, feel free to contact carel@ saao.ac.za or amanda@ saao.ac.za.''March 2015
== Change Log ==
'''Most recent changes at the top'''
* '''v1.4.2 Release date 3 January 2018<br>'''
** Feature: Better error reporting
** Feature: TCS info now available when mounted on the 40-inch
* '''v1.4.0 Release date 23 November 2016<br>'''
When running a series of exposures on the same target with different filters it
can be useful to make use of the automated acquisition mode on the camera tab.'''NOTE: SCRIPTING ALWAYS USES THE INTERNAL TRIGGER'''
[[File:scripting_1.png|1000px]]
When you click the "New script" option a dialog will appear giving you
<span style="color: red;">'''(1)'''</span> a text field to enter a name for your new script. You can then enter any
name and click the <span style="color: red;">'''(2)'''</span> "Create Script" button to create a new one. ''NOTE: Please ensure that your script has an easily identifiable name for the observer and run, e.g. Gulbis_20150617Script1Sickafoose_20150617Script1. All scripts are currently being stored in the drop-down web interface -- this means you will see other people's scripts and will have to look there for your own in order to load the script in subsequent observing runs.''
==Data Transfer==
There is an automatic transfer of data from the instrument to the file servers in Sutherland and Cape Town, every morning at 7:30. So you should not need to worry about the security of your data. However, you'll still need to access your data! We describe here how to do this. There are two ways to transfer get the data: (1) directly to your computer from the instrument PC or (2) onto from the SAAO storage area network (SAN). The data are automatically copied to the server every morning (at 7:30am).* To use method (1) To transfer data directly to your computer, use the command line.:
** Open a shell on your local PC (Putty if you're using Windows or a bash/tcsh/sh if on Mac or Linux)
** Copy the data using the following command, depending on the telescope:
rsync -avzP shoc40in@shoc40in.suth.saao.ac.za:"/data/40in/shd/2016/0503/*.fits" /LocalFilePath
rsync -avzP ccd74@astro.suth.saao.ac.za:/data/telescopedata/74in/sh?/<YYYY>/<MMDD>/*.fits /LocalFilePath
rsync -avzP ccd40@astro.suth.saao.ac.za:/data/telescopedata/40in/sh?/<YYYY>/<MMDD>/*.fits /LocalFilePath
* Below this, the readout speed and preamp gain may be set.
* Below this, the readout speed and preamp gain may be set.
* The last setting is the Electron Multiplying (EM) gain. <span style="color: red">NOTE: DO NOT USE ELECTRON MULTIPLYING MODE UNLESS YOU HAVE SPECIFICALLY OBTAINED PERMISSION FROM DR AMANDA GULBIS SICKAFOOSE TO DO SO, AND YOU UNDERSTAND HOW AND WHEN TO USE IT. PERMANENT DAMAGE TO THE SENSOR CAN RESULT FROM INCORRECT USAGE. If you are using EM mode, choose the EM output amplifier, and then select a gain. BEGIN WITH LOW GAIN VALUES, BECAUSE IF THERE IS TOO MUCH SIGNAL''' YOU CAN DAMAGE THE CAMERA.'''</span>
* When setting the horizontal shift speed, preamp gain and (if using EM mode, the EM gain), note the following: Higher readout speeds allow for shorter exposure times, but at the expense of noisier data, while higher electron to ADU gain values decrease the dynamic range. Read noise and electron to ADU gain values for each mode are provided in the PDF manual. In addition to this, it should be noted that as it takes about 6 milliseconds for the top-most pixel in the frame to be shifted to the storage area and SHOC does not have a shutter. The top row of pixels in each frame will have an exposure time of about six milliseconds longer than the bottom row. Consequently although it is possible (with enough subframing and binning) to expose for less than a hundredth of a second, this is inadvisable for the above reason. Finally, as indicated above, the 1MHz CON and EM modes are both 16bit. What this means is that the mode will reach saturation at 2^16 = 65536 counts. On the other hand, the 3 MHz CON and EM and 5,10 MHz EM modes are all 14-bit modes and saturate at 2^14 = 16384 counts. As the saturation limits of each mode will also depend on the electron to ADU gain, tables in the printed manual give the saturation limit in both counts and electrons for each mode.
* To get a quick view of the images that will result, press the "Preview" button. Images will be displayed in the left-hand display panel. Press "Stop" when you're done.
''This functionality should be available on the 74", the 40" and the new 1m. It has only been tested on the 74".''
The idea is to take a long, GPS-triggered data cube with SHOC at high cadence, while running the LED at 1 PPS (which has a longer pulse on the minute and can thus be used to test absolute timing accuracy).
*The dome and mirror covers must be OPEN for this test to work. (The GPS needs to get satellite signal, and the LED must be seen through the light path.)
*There is an LED mounted in the telescope optical path that can be used to independently verify SHOC timing. Log into the following website:
To use the command line interface:
** Fire up a terminal
** $ ssh <user>@<shocndisbelief|shocnawe>.suth.saao.ac.za** $ cd /home/ccd/programming/shoc/shoc/-gps** $ python -cli.py
** The commands in the cli are help, status, pop, mask, bias, timing_mode and location. Use "help <command>" for more information.
** The timing_mode option makes the GPS use static or dynamic mode.
