New Graphical Interface for SPLAT 1.3 (Win32)

Austin Wright (VE3NCQ) has been working on a new graphical interface for the Windows port of SPLAT v1.3. The new interface lets you specify the command line parameters in a more friendly way for those of you who don't like typing. You can check it out on his site.

You can find the creator of SPLAT, John Magliacane,  here.

SPLAT! 1.2.3 for Windows available

Sorry I haven't gotten this out the door sooner. SPLAT! 1.2.3 from John Magliacane has some bug fixes and accuracy improvements. More info is in the documentation. One feature that someone on the blog requested was the ability to save the GnuPlot temp files for post processing (re-scaling, etc.). This is the new -gpsav option.

Please let me know if you have any problems. If you are wondering what SPLAT! is, see this previous post.


http://people.missouristate.edu/jmcmellen/software/splat-1.2.3-win32.zip

SPLAT! for Windows featured in TV Technology magazine

Doug Lung, a columnist for TV Technology magazine, recently featured the Windows version of Splat! in his RF Technology column. The article provides a good overview of how to use Splat! in Windows for generating Longley-Rice coverage data and maps.

Measuring and logging HD Radio interchannel delay

The analog FM program audio and the main digital audio are supposed to be synchronized very closely to produce a clean blend between analog and digital when necessary at the receiver. With some work, you can synchronize these down to within a few samples. The problem now, depending on your installation, is keeping it synchronized. A lot of stations are finding that their digital signal drifts in time against the analog. The drift problem is being worked on, but for now, my concern is "How do I keep aware of how well I am synchronised?"

A ham operator and FM enthusiast, Brian Beezley (K6STI), wrote a command line program to cross-correlate the delay error between the two channels of a wave file and output the results to a text file. It seems logical to me that one could automate the recording of audio from a receiver in split mode to create many samples of audio for analysis. Then, another automated script could analyze the sample audio files and output the results in a statistical format. Since it doesn't have to be done in real time, all these data points (timestamped delay error values) could be saved and graphed, showing a nice graphical view of the drift. If you use a package like OpenNMS to collect and log the data, you could even get notification when it drifted outside certain limits. That is one way to keep on top of the drift and know how much it changes.

RF propagation modeling with SPLAT! for Windows

Many are probably familiar with John Magliacane's RF Signal Propagation, Loss, And Terrain analysis software (SPLAT!). This software is useful for visualizing terrain and performing Longley-Rice path loss and coverage prediction using the Irregular Terrain Model. It had been only available for the Linux OS. I was able to compile it for Windows with a few minor modifications. This is a command line program, freely available under the GNU GPL. I would be happy to include the source code if you are so inclined.

http://people.missouristate.edu/jmcmellen/software/splat-1.2.3-win32.zip

There is a PDF version of the instructions for the Linux version, which is pretty much exactly how it works in Windows too. Some utilities are included as well as instructions for downloading free terrain data for your area. I have only tested it in Windows XP SP2, so if you have any problems, let me know.

Fixes for Windows Port

• 11-12-07 - Fixed error in srtm2sdf.exe that caused it to not work with hgt or bil files.
• 11-15-07 - Fixed error in splat.exe that caused it to generate coverage maps without any loss data plotted when analyzing sites with anything other than default settings.
• 11-15-07 - Changed a trailing "/" to a "\" in the data path option. This never caused a problem in my setup, but might have in others.
• 2-15-08 - Successfully ported the usgs2sdf.exe utility to Windows. Now those who prefer the USGS DEM's as raw terrain data can convert them to Splat data files.