it looks like this footer info isn't even necessary for the output file to be recognized. it isn't currently included in the output (the lines below are unused in the function). It might be good to check to make sure this really truly makes zero difference for any data decoding and then delete these unused lines.
f1 <- "" # this is the number of messages
f2 <- "msgs 000>-120dB Best: -126 Freq: 677432.3 IQ : 66" # first line
f3 <- "Lat1: 34.716N Lon1: 76.672W Lat2: 34.716N Lon2: 76.672W" # second line
it looks like this footer info isn't even necessary for the output file to be recognized. it isn't currently included in the output (the lines below are unused in the function). It might be good to check to make sure this really truly makes zero difference for any data decoding and then delete these unused lines.