HOYS contributor, Mark Phillips, explains how he has tried to automate as much of the process of acquiring HOYS data and processing it as possible. What do you do?

By: Mark Phillips, Astronomical Society of Edinburgh

One of the good things about the HOYS project is that you can use very short periods of clear skies to gather useful data – and in Scotland where I live that’s very important! So I wanted to have everything setup so that I could make use of any clear periods and also automate as much of the process as possible. I’m currently using a QHY168C colour CMOS camera and there are a few tools that I’ve started to use to help me do that.

N.I.N.A. – NIGHTTIME IMAGING ‘N’ ASTRONOMY – an astrophotography imaging suite

NINA is a relatively new tool and I’ve just moved over to using it from APT (which is also excellent). Within it I can control:

  • Camera control, autoguider, focuser, telescope – and any other bit of kit you can imagine
  • Sequences – I’ve setup the HOYS target objects as two sets: Summer and Winter as well as sequences of exposures for each object (I do 3 x 180s for each object as well as darks, flats and bias)
  • Framing – this is useful if you want to image a slightly different part of an object than the coordinates give. This is useful for example where an alert has been created to image a particular star which might not fit within the normal field of view of a target.
  • You can also set NINA up to autofocus after a number of frames / or time / or temperature shift
  • NINA will also slew to each object, use plate solving to centre the object accurately and then start autoguiding.

So I can set the sequence running, it will slew and centre each object in the list, start autoguiding and then capture the images. All I have to do is monitor the clouds!

Data processing using SiriL

SiriL is also a relatively new piece of software (we’re using it in the HOYS-LCO project to create colour images) that has some neat scripting features that make it possible to automate the processing of HOYS data. As I use a One Shot Colour (OSC) CMOS camera I need to separate out the 3 individual colour channels to upload to the HOYS server. The script can do this for me.

You can download my script »
This needs to be saved in your user / Appdata / Roaming/ Siril /  scripts directory as a .ssf file (the download is a .ssf.txt file as I couldn’t upload a .ssf file to the site).

To run correctly you need to separate out your files into 4 directories within the SiriL working directory named: lights, darks, flats, biases.

To run the script simply choose the script from the Scripts menu and everything else is done for you. The process the script runs through is:

  • Stack and build the master flat, dark and bias
  • Pre-process the lights using these masters
  • Align and register the pre-processed lights
  • Stack lights to produce an RGB image
  • Split the image into 3 channels

At the end you have 3 files named TR.fit, TG.fit, TB.fit for the three tri-colour filters as well as an RGB.fit file.

There are a few things still to be done before I upload the files to the HOYS server:

  • set the filename to something meaningful – I usually name it with the HOYS number (eg H118), the object name (IC5070), filter (TR), camera temp (-10C), exposures (3×180), date and time, my account name
  • I also set the FILTER (TR, TG, TB) and EXPTIME (540s) in the FITS header

I have created a simple python script that does the naming and FITS header mods for me. All that’s left to do is upload the files to the HOYS server and process them there.

Happy to provide more info if anyone is interested or would find it useful.

Mark Phillips