# Correct Radar Range Equation for SNR at Detection

Assuming you'd like to estimate the probability of detection of a target for a monostatic radar.

For estimating detection SNR of a monostatic radar for given target rcs signature, do you use the energy or power form of the SNR equation?

Budge's Radar Equation Notes

Energy form of the SNR equation:

Power form of the SNR equation:

• Im not a fan of the Radar equation – user28715 Feb 5 '18 at 5:13
• I hate the time out on edits. tao of p is equal 1/B in his notes so they should be the same. Ive never seen anyone use units in a unit less ratio before. – user28715 Feb 5 '18 at 5:28
• @StanleyPawlukiewicz Why aren't you a fan of the "radar" equation?. Some people I know with the same opinion usually say because it's an "overextended Friis transmission equation"; or they have a more pedantic reason like "Because it's not called the Friis transmission equation". – Envidia Jun 1 '18 at 17:00
• @Envidia . It isn't really universal. There was a paper written in JASA about 20 years ago that noted that when you have a an active ping on an air filled steel cylinder , that is 30 feet in diameter and 300 feet long, suspended in 100 feet of water, the target strength and path loss terms are not independent. The careful decomposition of terms as separate engineering quantities breaks down. There are lots of cases where where the SONAR/RADAR/LINK_BUDGET equations need fudge factors to be accurate. Engineers tend to think of these as fundamental when they are really idealizations. – user28715 Jun 1 '18 at 17:29
• Back in the day, and even today they can be useful but a lot can be economically computed directly using things like Finite Element Models. The other criticism, is that terms like NRD (recognition differential) can be unreliable with humans in the loop. – user28715 Jun 1 '18 at 17:34