The localization methods based on signal amplitude are widely used in radio frequency based location system

wireless sensor network and acoustic location system.The conventional gain ratios of arrival (GROA) passive localization methods take no consideration of the altitude of the source

though it is usually known.A GROA model with known altitude of the source was proposed

and the Cramer-Rao low bound (CRLB) was also derived.And then

a localization algorithm based on Newton iteration was proposed and it was proved theoretically to reach the CRLB under the Gaussian noise data model.The simulations validated the theoretical conclusions.This algorithm was also verified in a wireless monitoring network.In conclusion

this algorithm can accurately localize the source with known altitude.