Smooth Summing Results in Excellent DF Sensitvity

Some people insist that radio direction finders based on the Doppler principle suffer from low sensitivity.  Recently I saw a claim from one of our competitors that their unit was 10 dB more sensistive than psuedo-Doppler based direction finders.  This is simply not true, and our data backs it up (see RF Sensitivity of Series 7000 (MPT) DF).  Although some direction finders do suffer from low sensitivity, it is not due to the psuedo-Doppler principle Read more…

Software Improvements

Last week I attended the NSREN conference in Orlando.  A big thanks to Paul Coburn for inviting us.  During the discussion times a number of good ideas were suggested for improving our software.  Throughout our history our customers have made suggestions for new features and new applications and our software is so much better because of those suggestions.  So please if you see something in our software you would like changed or you would like Read more…

New Version of MPT User Interface

We added a feature to the MPT User Interface program to allow a user to save the direction finder settings to a file. Once you have the direction finder settings the way you like them you can save them. If someone changes the settings you can always restore them to their saved values. The new version is available for download on our downloads page.

Doppler Systems Helps Find Culprit Jamming Aircraft Transmissions

Recently someone made hoax calls to pilots, causing a passenger flight to abort landing as it approached Melbourne Airport in Australia. In total there were 15 unauthorized transmissions on aircraft frequencies in the Melbourne area (see article here).  The Australian Communications and Media Authority deployed a Doppler Systems radio direction finder to assist the Australian Federal Police in finding the culprit.  Thankfully he was found and has been arrested (see article here).

Antenna Placement in a Mobile Installation

Frequently we are asked, “What antenna spacing should I use for my mobile antennas?”  This is a good question because many people think that antenna spacing would be critical for good performance and people are surprised when our answer is, “Somewhere between an 1/8 and 1/4 wavelength.”   In this post I’m going to present to you the results from the detailed model of our antennas to show the effect on error of antenna spacing and Read more…

Mounting a DF Antenna to the Side of a Tower

Over the years many of our customers have asked about mounting the DF antenna on the side of a tower or mast. Will it work? The short answer is not very well. We’ve posted the results of some extensive modeling we’ve done to predict the error associated with side mounting the DF array on a tower. To achieve a less than 5 degree peak error at 150 MHz the array must be mounted over 8 Read more…

Improved Mapping in TargetTrack

We released TargetTrack 3.2.0 last week. Several of our users had requested that we improve our bitmap based mapping functions. The previous versions of TargetTrack limited the map file size and the level of zooming. The new version allows for much larger file sizes and considerably more zoom levels. We’ve also added some more map like zooming and panning tools. The bitmap mapping facility in TargetTrack allows our users to make their own custom maps Read more…

Welcome to Our Blog

Welcome to the Doppler Systems blog. Our blog will give us the opportunity to keep you up to date on our latest products and software releases as well as offer helpful hints to enable you to use our products more effectively. Thank you for visiting and contact us if we can be of any assistance.