Using GPS trackers On-Site

References and experiences using GPS trackers for live tracking of long-distance sports events.

Basics

Most types of GPS trackers basically operate with the three main components:

1. GPS module: Determines the device's location.

2. GSM modem: Sends all data such as location, battery level, etc. via mobile network to the RACEMAP.

3. Memory: If the device is unable to establish a TCP connection with RACEMAP, no data can be sent, even if the GPS module is working perfectlyy. In this case, the data is stored in the device’s memory until a connection is re-established.

In RACEMAP tracker management system:

• The CON (Connection) column shows the duration since when the device established a TCP connection to RACMEAP respectively since when the socket was closed.

• The LOCATION column provides the duration of the most recent known location and the status of the GPS module.

Status of GSM modem and GPS module in the tracker dashboard

For example, during a trail run with poor reception - such as between the 30K and 38K marks - the tracker may temporarily lose its connection. During this period, real-time data won't be transmitted to RACEMAP but kept in memory. However, once the device reconnects, it will upload the stored data, filling in gaps in the race playback, so all data will be available in the event replay after a short delay.

You can see this relationship very well in the track chart.

Schedule commands

You can schedule commands for a group of GPS trackers to automatically adjust the devices' settings according to the time.

A couple of days before the race:

• Switch on all devices manually.

• Place devices for a good connection.

• Select all devices in tracker management.

• Check connection and location in tracker management.

• Clear undelivered commands from messages timeline before scheduling new commands with the "Revoke all messages" function.

• Schedule commands according to SLEEP, AWAKE and RACE profile.

• Don't switch devices off after you have scheduled commands.

SLEEP profile: "heartbeat", every 10 to 20 min refreshes the connection to Racemap, if there is reception

#	Command	Parameter	Time
S1	GPS Module	mode: 1	Now
S2	GPS Report Interval	3600; 3600	Now
S3	Non-Movement Detection	10; 3600; 3600	Now

• Participants must not use the power button! When deploying the devices to participants the devices are turned on already.

• Devices lose about 5 to 7 % battery level in 24 hrs.

AWAKE profile: It takes up to 60 min until all devices receive the new configuration. Check the tracker management if there is a device that does not establish a connection. The participant might have turned the device off. You still have time to change the device before the race starts.

#	Command	Parameter	Not before	Not after
A1	GPS Report Interval	180; 180	4 hrs before race starts	3 hrs before race starts
A2	Non-Movement Detection	10; 180; 180	4 hrs before race starts	3 hrs before race starts

RACE profile: It takes up to 10 min until all devices receive the new configuration.

#	Command	Parameter	Not before	Not after
R1	GPS Module	mode: 0	1 hr before race starts	no entry
R2	GPS Report Interval	10; 10	1 hr before race starts	no entry

• Devices lose about 5 % battery level every 1 hr.

• With 60; 60 parameter setting, devices lose about 2 % battery level every 1 hr.

For stage events you can schedule subsequent SLEEP and RACE profiles for each stage.

After the race: Use the "Shut down" command to remotely switch devices off. When the device has received the shot down it must be switched on manually. There is no possibility to remotely turn on a device.