The antcam is built using a combination of tools. First and foremost, each image is created using the radar program GRLevel3, and an overlay of spotters and chasers from spotternetwork.org. These images are normally published to the web server each time the radar image has updated, varying anywhere from 5 to 10 minutes.
The informaton about the spotters is updated more frequently, about every 2 minutes. Since the movement of spotters is the focus of this page, some trickery is done to get GRLevel3 to publish frames more often. Basically, if you make it think it hasn't published a file yet, it will do so. It's a rather cumbersome process, but if you have a PC that you don't touch, it's not so difficult.
The windows scripting tool AutoIT can control any program in windows by simulating mouse clicks and keyboard commands. I use this to open GRLevel3 using the desired radar site as a command line parameter for the script. The radar site is selected, it is zoomed out one step, web publishing is started, and then the radar image we want (br248) is enabled. This will grab the latest spotter network data, and publish the screen whether or not the radar image has been published before. Then GRLevel3 is closed, the downloaded radar .rv3 files are deleted, and it's opened again a minute later, starting the cycle again. Whew! Obviously, with all of this script activity, you can't really use that PC at the same time. I want to run this inside a Linux virtual machine, but haven't had luck getting GRLevel3 to run inside one yet due to it's directx requirements.
Each image is uploaded to this web server, where a shell and perl scripts make thumbnails, build animation scripts, and archive files to get what you see on the screen.
This process could probably be used to publish multiple radar web sites too, but the framework isn't set up to handle that. Often when there are two chase targets, you have to be lucky that the radar site chosen shows the activity best.
What is shown and what isn't? Only active, mobile spotters are shown. The rest are stripped out, including reports and name tags. This is free the screen of clutter, and to protect the innocent/guilty. :)
I welcome questions, comments, and suggestions, at tonyperkwx at gmail.
- Tony Perkins
Last updated April 17, 2009
Return to antcam
Return to F5Chaser forums