Example embodiments relate to methods and systems for implementing radar electronic support measure operations. A vehicle's processing unit may receive information relating to electromagnetic energy radiating in an environment of the vehicle that is detected using a vehicle radar system. The electromagnetic energy originated from one or more external emitters, such as radar signals transmitted by other vehicles. The processing unit may determine a spectrum occupancy representation that indicates spectral regions occupied by the electromagnetic energy and subsequently adjust operation of the vehicle radar system based on the spectrum occupancy representation to reduce or mitigate interference with the external emitters in the vehicle's environment. In some examples, the vehicle radar system may be switched to a passive receive-only mode to measure the electromagnetic energy radiating in the environment from other emitters.