Electro-Optical Tactical Decision Aids (TDAs) have proven their utility as tools for range performance modeling and mission planning. However, several TDAs are in current use in the United States armed forces. In fact, the services use different TDA codes which differ in the input data files and their sources required, in the operator expertise required, and the hardware required to run the program. Within the concept of Joint Operations, which has become crucial in the modern battlefield environment, all the services must share procedures, techniques, and often the same technology. This thesis presents a comparison between the Army FLIR TDA, (ACQUIRE), and the infrared module of the Navy/Air Force TDA, WinEOTDA. Differences in the modeling of underlying physical principles, input parameters, and predicted target detection ranges are presented. Despite differences in input and treatment of environmental effects this analysis indicates similar levels of accuracy for the two codes. For two scenarios selected average predictions for three typical sensors fall within 20% of published observations. With further analysis and an operational evaluation it may be possible to select one Electro-Optical Tactical Decision Aid for all branches of the military.