Handling Video Data

To date in the project we have been using a mini-DVR for recording video for our occultation events.  In my last posting, I talked about the problems discovered with this approach.  Since then I have been working on setting up a new data recording system. This week marks the completion of that work and new data collection tools will be shipped out to all the teams. This document discusses the changes and the reasoning.  New training documents will also be made available shortly to help with the transition.

We are going to now use netbook computers in the field for data collection. I tried a couple of different systems and settled on an Acer Aspire V5 running Windows 7.  These systems will come pre-configured with VirtualDub, OccultWatcher, LiMovie, Chrome, LibreOffice, Skype, Occult, and a few other useful utilities.  These computers should not be used for general tasks, instead they are project machines for things like collecting data, transmitting data to SwRI, and signing up for events.  A small amount of customization of each system will be required, such as putting in your OW credentials.

Each computer comes with a video frame grabber interface (StarTech SVID2USB2) and a video cable that will connect to the output of the IOTA-VTI box.  Inside the box are also a couple of spare fuses as well as some of our cool new RECON stickers.  I recommend using at least a few of these stickers on the equipment (telescope, telescope crate, and so on).  If you need more, let me know.

I think you will all like the new system.  It’s not so great for dark adaption, the screen seems really bright at night even turned all the way down. But, you’ll be able to get a bigger image on the screen than what’s been possible with the mini-DVR and you’ll find that focusing and finding the field will be easier since you can see it from a distance while operating the telescope.  The program, VirtualDub, is what you run to see the video signal coming in.  Once you turn on the capture mode the video is live.  Stay tuned for a more detailed document on how best to setup and use this program.

The data quality from this setup is exceptionally good.  There is a price, however.  The files you have been collecting with the mini-DVR up to now are really quite small.  The new system makes much bigger files.  The data rate is about 200Mb/minute and your upload times will be significantly longer.  Unfortunately, this can’t be helped but the extra time will pay off in the increased scientific value of the data.  Note that the data are compressed pretty well already.  You won’t get much more out of using zip other than to pack a bunch of files into one clump for a single upload.

Everyone should see their systems arriving late this week or early next week.  I’m trying to get this equipment in your hands in advance of the 2001XR254 event in early March. I’m confident you’ll be able to make the switch in time but in an emergency the mini-DVR will be able to handle this upcoming event.