See Also: GRAS Video Tutorials,  FAQ , Opening Plays or Pete’s FoV

 

Software Suggestions

Most GRAS telescopes (G3 produces JPEGs for Demo users) deliver all image files in 32bit FITS format. Fits or (Flexible Image Transport System) is a standard image format used in astronomy. While it can store bitmaps of astronomical images, it can also store astronomical/scientific data.

If you are a full member of the GRAS system then you will need to retrieve data from your GRAS FTP folder, this can be done via the GIS control page, but some internet browsers (IE for example) make it difficult for some. So we recommend other applications as a reliable options -  FTP Surfer or Core FTP LE

A planetarium or sky simulation software package will be useful. This will allow you to ‘see’ and navigate the skies above the telescopes and plan your sessions efficiently. Eg maximum elevation and clearance from the moon of your targets etc. A good map will allow you to precisely aim the telescopes at your desired RA - Dec coordinates as well.

We recommend Stellarium (free), Starry Night or TheSkyX. 

Another useful tool would let you preview the field of view and see details on the CCD / Telescope combinations. We recommend CCDCalc - A Free Visual Calculator.

This link will take you to a list of Astronomy related software. Some free, others are commercial. Many have free demos or extensive trial offers.

 

 

 Stellarium use with GRAS

 

Data Reduction Software

If you really want to get the most from your raw 32bit images then you will need an image reduction and enhancement package such as MaximDL or CCDStack which offer free trial periods.

CCDStack provides all the tools you need for your image processing workflow:

  • Dark, Flat and Bias frame calibration (Optional)
  • Star Bloom Removal
  • Image alignment and registration
  • Re-sampling of registered images
  • Image normalization
  • Advanced Data Rejection
  • Image Combine
  • Gradient Removal
  • Real-Time DDP Display
  • Deconvolution and Sharpening
  • Full LRGB Color Capabilities
  • Pdf Tutorial Here
  • See demo Video.

 

Useful Astronomy Odd and Ends

Online Ephemeris: http://www.ephemeris.com/ephemeris.php

WebCCD Simulated image of any Field of View: http://observatory.tamu.edu:8080/webccd/

 

Books on CCD Imaging & Amateur Science

If you really want to understand imaging, reading these books can really help you understand a lot more about CCD cameras and image processing.

The Books, “The New CCD Astronomy” and “The Zone System for Astro Imaging“  are co-written by Russ Croman, who is a friend of GRAS and one of the worlds best Astrophotographers. We highly recommend them as additions to any astro imaging library.

Want to do some science, so where to start?

Probably the very best place start is Robert Buchheim’s book, The Sky is Your Laboratory. 

In 293 pages, Buchheim covers just about every field of astronomical research that is within the reach of the self-funded astronomer. Of particular interest to GRAS observers in the data gathering and analysis area (Chapters 4 and 5) are Project H, CCD photometry of variable stars, Project I, determining asteroid light curves, Project J, extra-solar planet transit, Project L, asteroid astrometry (comets too!).  Project M, measuring visual double stars.

Plenty of reasons to get the Lab Coat out and do some serious science with GRAS.


FITS Liberator

By Dr Ian Musgrave

As people know, I’m a fan of low cost astroimaging. For GRAS remote telescope images, my workhorse is the freeware ImageJ. This works pretty well, especially for stacking and aligning images. However, astronomical images can have a large dynamic range from the very faint to the almost overexposed. How to bring out faint structure without turning the bright sections into glaring blobs?

This is where FITSLiberator comes in, it’s a freeware app (also there are photoshop plugins), which makes it very easy to adjust the dynamic range of your images for later assembly in other image processing programs (You can do something similar in ImageJ but it’s not as easy). As you can see in these images, with FITS liberator I was able to adjust the dynamic range of my Tarantula Nebula images to almost match the brightness of the multi-stacked images, without the central regions getting overexposed or the background being over-coloured.

Obviously my Tarantula Nebula won’t win the astrophotography contest, and I still have a lot to learn, but I’m going to get a lot more out of my images now.

The FITS Liberator website comes with links to a whole range of Hubble raw images, and step by step instructions so you can create your own version of classic Hubble pictures. The PDF user manual is here.

Left Image: Tarantula Nebula imaged using GRAS 14 instrument with 3 x 120 sec Red filter FITS images, 3 x 120 sec Green filter FITS images and 3 x 120 sec Blue filter FITS images. Each series of individual filter runs stacked using in Image J using Z projection of maximum intensity, then stacked and assembled into a RGB composite using ImageJ.

Right Image: Single 120 sec RGB filter FITS images stretched using FITS liberator and ArcSinh(x) stretch. Stretched files stacked and assembled into a RGB composite using ImageJ.

These are smaller frames of the nebula cropped from the full image. You really, really need to click on these images and embiggen them (and then compare to this APOD image taken on a GRAS system which is 31 hours of exposure).

Ian Musgrave

How to use VPHOT

VPHOT is an online photometry application for AAVSO members, and is seamlessly integrated with the GRAS systems. If you choose to send your images to the VPHOT server they will automatically be calibrated and plate solved, and ready for photometric analysis in VPHOT online. Note that it might take 10-30 minutes before the images appear in VPHOT depending on network traffic, server load etc.

In order to use VPHOT you have to be an AAVSO member. You start by going to the AAVSO web site at http://www.aavso.org/ and log on to their web site with you AAVSO user name. Then you enter the VPHOT server via the link at the bottom of this page:

http://www.aavso.org/vphot

Before you can see your images in VPHOT you need to tell the system your GRAS user name so that it can correctly identify your images as they come in from the GRAS telescopes. To do this, you click the ‘Admin’ link in the top menu of VPHOT, and then click ‘Image Transfer (Connect Accounts)’. Follow the instructions on that page. You only have to do this once.

Each page in VPHOT has a help link that explains the details of that particular page. You can also view the excellent video tutorials below.

Note that some features has changed and new ones added since these videos were made, but the main features are the same.

These video tutorials have been produced by Ken Mogul.


Please direct questions and comments to the VPHOT forum.

Video Software Tips

A selection of basic and more advanced tips for GRAS Imagers.  (More Tutorial Videos HERE)

Getting the most from One Shot Color FITs Files

A short video produced by GRAS Affiliate Christian Sasse showing us how to get the most from those color FITS files you may have gathered from GRAS-015 or GRAS-003 using Photoshop.