Hi Endy0816,
Thanks for the reply. The image i've attached shows the NMEA protocol string. The string data starts with $GPRMC has knots value. for example
$GPRMC,123519,A,4807.038,N,01131.000,E,022.4,084.4,230394,003.1,W*6A Where: RMC -Recommended Minimum sentence C 123519 -Fix taken at 12:35:19 UTC A -Status A=active or V=Void. 4807.038,N - Latitude 48 deg 07.038' N 01131.000,E - Longitude 11 deg 31.000' E 022.4 - Speed over the ground in knots 084.4 - Track angle in degrees True 230394 - Date - 23rd of March 1994 003.1,W - Magnetic Variation *6A - The checksum data, always begins with *
the image i've attached has knots 4.34, and next GPRMC data string has 4, next has 4.29, 4 and so on...
Here is that i have to calculate difference between two knots and time, then multiply the two values? for example 4.34 - 4= 0.34 knot and time 5 sec - 8sec = 3 sec, so the distance is 0.34*3=1.02 .? Is my calculation is correct?