Longley-Rice Model

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The Longley-Rice (LR) radio propagation model is a method for predicting median path loss for a telecommunication link in the frequency range of 20 MHz to 20 GHz.

LR is also known as Irregular Terrain Model (ITM). It was created for the needs of frequency planning in TV broadcasting in USA in 1960s and was extensively used for preparing the tables of channel allocations for VHF/UHF public broadcasting in USA. LR has two parts: a model for predictions over an area and a model for point-to-point link predictions.

[edit] Publications

A description of the method was published by the US government under the title "Prediction of Tropospheric radio transmission over irregular terrain, A Computer method-1968.", A. G. Longley and P. L. Rice, ESSA Tech. Rep. ERL 79-ITS 67, U.S. Government Printing Office, Washington, DC, July 1968. This document followed on an earlier publication titled "Transmission loss predictions for tropospheric communication circuits", P.L. Rice, Volume I & II, National Bureau of Standards, Tech. Note 101.

[edit] External links

Further information on Longley-Rice model, including a full description of the algorithm and source-code examples can be found on the website of U.S. Department of Commerce NTIA/ITS, Institute for Telecommunication Sciences.