To analyse a RF prediction model and determine the accuracy, a itterative process called model tuning has to be deployed. In this process a number of steps have to be followed and at the end you have tuned the model and you know the accuracy of the model.
This process is applicable all RF propagation models an not only for the model used in Radio Mobile.
The full process is described in a flowchart and references are added to some other topics on this site.
Please be aware that this description is only a global one. In professional model tuning more topics need attention and quality and accuracy are very important.
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In the following step one fase out of many is described. This step must be repeated until a satisfying result is reached.
It is important to keep a track-log of the steps you have made and the results. For a example I have added the track-log of one of my model tuning exercises:
Track-Notes example.
Folder object06 Version 900 Frequency 169-170 MHz Fixed Unit: Arendsburgt @ 37 meters 25 Watt +42 dBm Erp using dipole + 2 dB cable loss Mobile unit: mobile @ 1 m RX sensitivity -120 + 2 dB cable loss Model settings: SR 300 N GC 0,005 S/m RGP 15 Martime temperate over land Variablility: Spot 75% Use 'Two rays' for line of sight: YES / Normal Landcover ON Step Height Forest Height City File Average error Stdev 1 Default RouteResult06_01.xls 16,8 6,2 Step Height Forest Height City File Average error Stdev 2 0 50 10 100 RouteResult_02.txt 17,8 6,2 3 0 100 10 100 RouteResult_03.txt 17,8 6,2 4 1 100 10 100 RouteResult_04.txt 12,5 5,5 5 1 200 10 100 RouteResult_05.txt 7,1 5,0 6 1 300 10 100 RouteResult_06.txt 1,8 4,7 7 1 400 10 100 RouteResult_07.txt -3,4 4,5 8 1 500 10 100 RouteResult_08.txt -8,7 4,7 Use 'Two rays' for line of sight: YES / Interference Step Height Forest Height City File Average error Stdev 9 1 300 10 100 RouteResult_09.txt 2,29 4,3 Use 'Two rays' for line of sight: NO Step Height Forest Height City File Average error Stdev 10 1 300 10 100 RouteResult_10.txt 2,19 4,3 Moved to object08 New route through urban and forest Use 'Two rays' for line of sight: NO Step Height Forest Height City File Average error Stdev 11 1 300 10 100 RouteResult_11.txt 3,5 4,9 Use 'Two rays' for line of sight: NO Step Height Forest Height City File Average error Stdev Urban Forest Combined 12 1 300 1 200 RouteResult_12.txt 0,06 5,2 13,63 9,52 -1,734 Use 'Two rays' for line of sight: Interference Step Height Forest Height City File Average error Stdev Urban Forest Combined 13 1 300 1 200 RouteResult_13.txt 0,08 5,2 13,63 9,52 -1,734 Changed bare ground and grassland and cropland to 1 m 1% Step Height Forest Height City File Average error Stdev Urban Forest Combined 14 1 300 1 200 RouteResult_13.txt 0,08 5,2 13,63 9,52 -1,734 Changed bare ground and grassland, cropland, Open Shrubland to 1 m 1% Step Height Forest Height City File Average error Stdev Urban Forest Combined 14 1 300 1 200 RouteResult_13.txt 3,08 6,17 13,63 4,93 2,48 |