How is the weather data coded into the packet?
When you look at examples of APRS position weather packets here, or here, the part after the longitude “E” or “W” carries the weather data as symbols followed by numbers. The underscore “_” followed by 3 numbers represents wind direction in degrees from true north. This is the direction that the wind is blowing from. The slash “/” followed by 3 numbers represents the average wind speed in miles per hour. The letter “g” followed by 3 numbers represents the peak instaneous value of wind in miles per hour. The letter “t” followed by 3 characters (numbers and minus sign) represents the temperature in degrees F. The letter “r” followed by 3 numbers represents the amount of rain in hundredths of inches that fell the past hour. The letter “p” followed by 3 numbers represents the amount of rain in hundredths of inches that fell in the past 24 hours. Only these two precipitation values are accepted by MADIS. The letter “P” followed by 3 numbers represents the amount of rain in hundredths of inc
