GPS-Tips

 

The GPSResults program can be used to calculate and evaluate the track-velocities from measured GPS-data.

First of all the data have to be read from your GPS and transferred to your computer. For this purpose you can use GPSResults or g7towin (freeware, can be downloaded from the internet).

 

Download and save your GPS-data in gpx-format

 

Connect your GPS with the serial data cable to the serial port of your computer (use a USB to serial converter if your computer doesn´t have a serial port anymore). Configure the COM-port used (in this example COM2):

 

for the Garmin Foretrex101 and 201 the datacable looks like this:

 

 If you use a USB-serial converter you can find the COM-port in the device manager:

Now the measured Trackpoints can be read from the GPS (important: set your GPS to the dataformat WGS-84 and the transmission protocol Garmin). (File -> Download Trackpoints from GPS...):

If you have measured Waypoints in order to determine the gate positions, read and save these data as well (Extras -> Download Waypoints):

The transmission of the data may take a while, since the datarate from the GPS to your PC is rather low (9600 Baud = 20 trackpoints/sec). All data (Trackpoints and Waypoints) have to be saved in the gpx-format.

If there are several competitors the filenames should contain sailnumbers or the competitor names since in the ranking list the original gpx-filenames will be used.

 

GPS-Devices

 

Required features of GPS devices are a serial or USB data interface, a large number of trackpoints that can be saved (e.g. 10.000), and that the measuring interval can be adjusted (1 or 2 seconds between measurements). For example Garmin® Foretrex 101, Foretrex 201, Geko 201, Edge 205, or Amaryllo NaviGPS®.