What: New Approach: AM Coverage, Interference
When: October 26, 2003 7:00 PM

This presentation covers a methodology for using FCC's accepted rules and propagation models to produce an AM grid-based analysis of coverage, interference & Quality of Service (QOS). These maps are similar to the tiled matrix maps currently used in FM evaluations

While computationally more expensive than contour analysis, the methodology uses a structured grid approach that, produces data with a fine degree of granularity which is much better for computing combined groundwave and skywave signals. This approach is also ideal for determining signal and interference for any location across the United States and for analyzing population and other statistics of the entire frequency band. These advantages combine to produce a model of the AM allocation scenario that can be used to produce many different quantitative metrics and conclusions concerning the existing levels of interference and how that may change with the introduction of new services.

In this study, a 410 x 901 element grid was drawn over the entire United States (based upon a 4-minute interval in latitude and longitude). The total groundwave and skywave signals from all nearby, relevant stations were computed at each point on the grid. The study resulted in the ability to produce color coded tiled matrix maps for every US broadcast licensed AM station depicting. 1), Total RSS'ed groundwave for daytime and total RSS'ed groundwave and skywave signal strengths for nighttime 2) The co- channel D/U ratios, 3) The First adjacent channel D/U ratios and 4) Various Quality of Service maps with the data presented in tiled cells of Mean Opinion Scores (MOS).