In my previous post, I stated several arguments for a standard file format for holding astronomical observations. The arguments fell into 3 categories: data preservation, flexible access to and presentation of the data. This time, I'll describe a candidate that solves many of these requirements that is available now. Better yet, it is open source and free.
A year or so ago I stumbled upon something that really solved the aforementioned requirements well - an open source XML based standard for recording observations called COMAST. The advantages of recording observations in an XML format are that the content of an observation can be defined clearly for any interested party (program) to produce or consume. XML also lends itself well to reformatting into different file structures or visual presentation. All of this presents in a platform independent context. If you are keeping tally, that's open source, free of charge, platform independent, flexible access and flexible presentation. Hmmm, cool.
The COMAST effort is led by a small number of developers from Germany and Belgium. Fortunately for me, there is English documentation (my German is pathetic.) If you would like to read about the COMAST XML Schema, you can visit the web site at http://observation.sourceforge.net/en/index.html Beware if you aren't an XML techie.
After studying COMAST for some time, I decided that it described observations well enough and generally enough to be a very good candidate solution to my perceived requirements. I decided to put it to the acid test - try to import and export observations from Deep-Sky Planner using the COMAST format. After some discussion with the founding designers of COMAST, I have succeeded in transferring COMAST formatted data into and out of Deep-Sky Planner. There are idiosyncracies, but it works. Double cool.
COMAST does a thorough job of describing your observing site, equipment, time of observation and visual results. It can currently accommodate imaging equipment and results, but not as thoroughly as I would like. Deep-Sky Planner continues to provide storage and reporting of imaging observations. I suspect that the COMAST standard will catch up and I hope to take part in that effort.
COMAST does include some data that is more relevant to German observers, like one's Deep-Sky Liste (DSL) ID number and a DSL object rating code. I'm sure that observers elsewhere have familiar rating systems, association IDs and the like. These items reveal the roots of the COMAST project but they aren't required. They probably should migrate into an extension for German observers from the basic standard, but for now they can be ignored if desired. The nice thing about the COMAST design is that it makes extensions possible with predictable results. For example, should there be an extension developed that describes imaging observations, older software could accept and produce legal files with no changes - it would simply not support imaging extensions.
So what can COMAST do for you? At present, it can provide you with a observation data migration path between a couple of software products. Should that number increase, we may just have ourselves a viable world standard for sharing and preserving observations. Very cool indeed.