Wow this is even better than the last paper.
I will give you little background in what I am doing, I work for a state agency and with the last testing I did back in 2011 we were looking for loss factors due to belt mounted VHF HT-1250 radios inside railroad tunnels. We had numerous incidents where signal men were unable to talk to the rail controller in the middle of the tunnel even though it is only 1/4 mile long and the base was only 1/2 mile away, but offset by 50 yards from the mouth. VHF realy doesn't like tunnels, and the testing wasn't totally scientific, but we took DAQ reading (I know not very scientific) every 10 ft on the hip and at mouth level and even closer in the problem area. Then facing in 0,90,180,270 degrees from the end of the tunnel, but this gave us enough information for us to issue 5/8 wave antenna's like the EXH160 made by Laird. Which corrected the problems at this location.
Now this new testing is a little more intense and is scientific, we use EDX software to plot our systems coverage, and we are trying to determine the loss factors from inside a moving revenue car to a base station up to many miles away. I knew I had the original document that I believe was from Motorola, but cannot find it, and I basically remember a loss factor of -9db over isotropic.
This time for testing we are going to use 3 stationary Anritsu 410's outside the car located facing in the middle and at each end while we walk back and forth with a hip mounted portable transmitting 1k tone for a relative Sinad measurement and RSSI. This test will be run staticly in a yard clear of other cars on both sides, and many times to come up with an average that we will use as an offset against measurements taken outside the car.
As far as I can see this is the first time someone has tried to get such an offset on VHF for rail cars at least.