RADAR and SONAR are both detection systems that can be used to identify objects and their position when they are not visible or at a distance. They are similar in that they both detect the reflection of a transmitted signal. This makes them easily confused with one another. They also both also serve as acronyms for a much longer description, with RADAR being short for Radio Detection and Ranging and SONAR for Sound Navigation and Ranging.There are also additional differences between the two.