The proliferation of low-cost and highly capable Software Defined Radios (SDR) makes it difficult for the soldier to keep his/her communications systems secure from adversary SIGINT systems that can find, fix and finish radio frequency emitters. Radio communication systems that were not designed with this level of threat in mind are susceptible to exploitation, specifically in the area of geolocation and tracking.Adversary SIGINT systems can choose from a multitude of different geolocation techniques and this diversity of techniques makes it extremely difficult to prevent an adversary from performing geolocation on an otherwise secure communications link.Currently, there are no effective countermeasures to prevent geolocation of tactical radios.Investigation by industry is minimal due to this mainly being a problem for the military. In this proposal the Aspen Team will provide a methodology and will identify several promising techniques that will be explored to obfuscate the location of tactical radios via signal processing and hardware applique modules. Aspen is uniquely postured to investigate techniques to introduce spatial uncertainty into radio communications geolocation systems based on its expertise in RF geolocation, communications, signal processing and waveform generation in support of multiple US Army programs.TDOA,Geolocation,obfuscation,SIGINT,direction-finding,Communications,radio-frequency,localization