Personal Locator Archives - GPS Tracking - RavTrack Complete Real Time Tracking

August 29, 2013January 14, 2018

Why Use GPS Trackers Instead of Two-Way Radio?

Sometimes two-way voice radios can be used for safety and personnel locating. When trying to decide if a dedicated GPS transponder like the Raveon ATLAS PT or a voice radio is the right choice, keep these important points in mind:

You will know where everyone is at all times. A GPS Transponder operates at all times, not just when the user presses the PTT button.
Battery Life. A GPS transponder can run for days on a single charge. Most portable radios will operate 8 hours or so. If used a lot or the PTT button is accidentally pressed, the batteries will last much less.
Emergency Assistance. In an emergency situation, both technologies can be used to summon help. But if the person is incapable of moving or unconscious, pressing a PTT button is not possible and the GPS transponder will not only continue to send the locations out, but alert that no motion is taking place.
Search and Recovery. Raveon’s GPS transponders automatically, continuously, and quickly transmit GPS location and status. Rescue personnel can use a tablet or laptop computer to locate the transponder in real-time, live while searching. Finding the transponder and locating the personnel can take only minutes. View our asset tracking and safety infographic, which describes how the Ravtrack system is designed.
No Voice Communications. In many situations it is undesirable to have the people being tracked to be able to talk amongst themselves. This could be for training purposes, privacy, or security. Or, they may already have voice radios, and real-time tracking using a dedicated channel frees up many other channels for voice comms.
Fast Updates. GPS locators in voice radios are very slow to update, and take a lot of air-time. Tracking hundreds of vehicles or people requires an advanced channel-access protocol like Raveon’s TDMA protocol.
Log Files. With fast updates, the system can store GPS data to log files for later review or in case there is an incident, the log can be queried to determine what happened during the incident.
Keep People Honest. Often GPS tracking is done to monitor behavior to verify that they are following rules and staying within limits and boundaries. Voice radios will not help in these situations. Voice radios can be turned off (The ATLAS PT’s power button can be disabled), and people disrespecting their restrictions will probably not get on the radio and announce it.
Rugged. The ATLAS PT is submersible to 1 meter of water, very rugged, and made from aluminum. Few plastic voice radios can take the abuse the ATLAS PT can. When people lives are at stake, a rugged, long-life product is important.

Comparison of Features

*Feature*	*GPS Transponder PRO*	*GPS Transponder CON*	Voice Radio PRO	Voice Radio CON
Voice Communications	User’s Can’t communicate. Security. Privacy.	Cannot call for help without pressing the ALert Button	Users can chatter amongst themselves.	Users can cheat if they are supposed to be on their own. Voice comms takes up bandwidth used for GPS tracking.
Battery Life	Excellent 24-48 hours		8-12 hours
Real-time Tracking	Excellent			Cannot Do
Safety System	Great situational awareness	No voice. Cannot talk to rescue.	Can talk to rescuers	Must manually press PTT. No help for unconscious personnel.
User Cannot Turn Power Off	Always On when needed	Requires charger to shut off.	None.	Users can turn radio off if they don’t want to be tracked.
No Motion Alert	Automatic Transmission if idle to long.	Sometime false alerts when sleeping/resting.	None	Few voice radios have this feature.
Live Tracking by Searcher and Rescue	Rescuers, cadre or commanders can drive right up to the transponder.	None	Personnel can use voice to help direct searchers to find them	Sometimes difficult to explain location. Person must be conscious. Person must know where they are.

To learn more about the advantages of the RavTrack system, attend our webinar.

December 17, 2010

The RavTrack Atlas PL personal GPS locator radio network capabilities

Most people will identify the Atlas PL personal locator as an excellent device for people to wear and to send GPS position information, alerts, and man-down status. Typically the Atlas PL is used in conjunction with the RavTrack AVL GPS vehicle transponders which are equipped in fleet vehicles and used for base receiving stations as well as store-and-forward repeaters. It is common for these latter transponders to be used to complete a GPS tracking radio network for tracking both personnel, and vehicles, or other costly assets.

However, it is also possible for the Atlas PL units alone to be used to construct a GPS tracking network complete with multiple base stations and/or a repeater, without the involvement of the vehicle transponder models in the system. The Atlas PL inherently has all the capabilities of the vehicle based models. Releasing these capabilities is simply a matter of following correct configuration procedures for the Atlas PL.

The following diagram demonstrates the use of the Atlas PL in its traditional role as a personal GPS transponder but also as multiple base stations, with one base station also serving as a repeater.

Within each box are typical settings of the Atlas PL as part of the GPS tracking scheme. Above each box are the intended uses of each Atlas PL in the tracking network, while below each box are a series of configuration commands the user should issue to each Atlas PL unit to configure each unit for the particular use specified. Finally, alongside each command is an indication of what that command actually configures in the Atlas PL.

Each Atlas PL starts out in GPS mode 8. This configures the Atlas PL to function in the most common transponder configuration and enables the advanced battery management functions of the Atlas PL as well. However, it is important to note that the command GPS – such as GPS 8 – is a macro command which configures many different aspects of the unit. Most commonly the GPS command is understood by the user to set the format of the NMEA output, but it in fact does much more. For instance, issuing the command “GPS 8” to an Atlas PL will completely turn off the receiver circuitry of the unit. This is not what we need for a base station receiver or repeater. The subsequent commands change other configurable attributes of the Atlas PL, overriding the macro set of configuration parameters, to arrive at the final desired configuration. It is critical these configuration commands be issued after the GPS command.

We hope this demonstrates some of the capabilities of the Atlas PL not commonly identified by the end user. Should you have in mind a specific function of an Atlas PL that is not apparent, we encourage you to contact us.

August 19, 2009October 6, 2009

ATLAS PL Personal Locator Battery Performance

The ATLAS PL Personal GPS Locator operates off of two internal Lithium-Ion battery packs. Combined, the two batteries deliver 6.8 – 8.6V to the internal radio circuitry. As the ATLAS PL is used, the batteries discharge, the battery voltage drops, and the RF power will slightly decrease.

Below is a table showing typical RF power output verses battery life.

Time (Hrs)	Cell Voltage	Pack Voltage	% Battery Remaining	RF Power Output	TX Current
0	4.30	8.60	100%	5.0
1	4.10	8.20	92%	4.7	2.9
2	4.00	8.00	83%	4.6
3	3.90	7.80	75%	4.4
4	3.85	7.70	67%	4.4
5	3.82	7.64	58%	4.3
6	3.80	7.60	50%	4.3
7	3.75	7.50	42%	4.2
8	3.70	7.40	33%	4.2
9	3.68	7.36	25%	4.1
10	3.65	7.30	17%	4.1
11	3.50	7.00	8%	3.9	2.8
12	3.40	6.80	0%	3.7

The above data is represented graphically in the following chart:

Atlas PL battery voltage chart

The time duration that the ATLAS PL will operate before its batteries must be recharged is dependent upon the GPS mode and the position transmission/update rate.

Below is a chart showing approximate battery life. The Green line is if the PL is operating in GPS mode 2, 4, or 9 with the UHF radio receive enabled. The Blue line is GPS mode 9 with the receive disabled (Transmits position only).

pl_batterylife_1

pl_batterylife_2