eLMS: FCCdata FM contour maps

A new eLMS function now obtains service contour data from the FCC Contours API based on GLOBE30 terrain data and stores in an eLMS table.

Contour maps for FM engineering applications filed after September 25, 2019 and filed in LMS now use eLMS contour data whenever possible.  This will hopefully resolve some of the issues that we have been having with the previous method of calculating field strength curve distances (which was done locally) causing some strange artifacts on contour maps (such as the "wings" effect on deep nulls in directional antennas).

If an eLMS contour map is available for a particular FM record, that data will be used on the service contour maps in FCCdata.   

Adding functionality on CP & MOD applications for LPFM stations that are nondirectional and within 125 km of the Mexican border to CAP the ERP at 50 watts.

On LPFM applications where on the parsed LMS application it shows an ERP unit of W (watts) and a value of less than 1, it will treat the value as kW (kilowatts).  For example, if an application is parsed at 0.05 W (50 milliwatts), the power will be changed to 0.05 kW (50 watts). 

On Thursday, we plan a re-run of LPFM records through the parser and contour generators to true up LPFM records to take advantage of these changes.

 

Date: 
Wednesday, August 26, 2020
Systems affected: 
FCCdata.org
Issue type: 
Enhancement