The most common issue that new customers experience with their GPS device is poor tracking results caused by a less than optimal antenna location. In this article I will review some of the most likely antenna locations and rate their relative strengths and weaknesses.
One thing that all GPS tracking devices have in common is the need to receive a Global Positioning System satellite signal that is strong enough for the device to calculate its proper location on planet earth. If the unit’s antenna is placed in a location that is hidden from the GPS satellites, the unit will either stop reporting location updates entirely, or it will begin to “guess” at its location based upon the weak signal. Neither of these scenarios is very useful to the device owner, so it is important that the antenna is placed in a spot where it is able to pick up as much signal as possible.
The number one rule of antenna placement is that GPS satellite signals do not pass through metal. That may seem like a big limitation when you are considering placing a tracking device on a vehicle, but it is not as bad as it initially sounds. The signal can bounce around inside the interior of a vehicle, and many of the interior and exterior components of modern day vehicles are made of materials which the signal can pass through. Let’s take a look at some of the typical locations that our customers have tried to see how well they may, or may not work:
1. In the Trunk: It seems as if there is at least one show a week where the TV cops are sticking a GPS tracking device the size of a coat button in the trunk of a car, and then watching the device update on a computer screen every five seconds for weeks at a time. That is TV, folks, and the technology of the real world is not that good yet. A device that small would have a battery so tiny that it would only be able to transmit location updates for a few hours at best. And unless the trunk is made of fiberglass or is a design that does not really have a trunk (hatchback, SUV, station wagon, etc), there will not be enough GPS signal in the trunk to get reliable reporting.
2. Under the Car: This is a popular choice among first time users, and I understand the temptation. We sell magnetic brackets for most of our devices, which most people assume are designed to allow the device to be stuck up underneath the car. That can be true, but we also sell external antennas for our covert tracking devices for an application such as this one. If the device is placed underneath the car or in the trunk, you will almost certainly need to route an external antenna out to a spot that will be able to pick up a good GPS signal.
3. Under the Front Passenger Seat: This can be a good spot when a customer is looking for a covert location on the inside of the vehicle, and is often the favorite spot among users because it is such an easy location to work with. The only downside is that the satellite signal may be diminished when someone is sitting in the seat, but the device often works well whether or not the seat is occupied.
4. Under the Dash: This is our first choice when it comes to covert locations for a tracking device inside the vehicle. You typically get lots of GPS satellite signal streaming in through the front windshield, and signal passes through most of the materials used to construct the dash with relative ease. You do need to be careful not to secure the device underneath part of the dash that is constructed of metal.
5. Under the Hood: Please re-read the part about the trunk. It’s pretty much the same story under the hood.
6. In the Bumper: We work with a lot of law enforcement services and private investigators requiring covert surveillance, and this is their location of choice when they do not have access to the inside of the vehicle. For most new vehicles, there is an outer plastic or fiberglass cover over the main bumper. Behind this cover, there are usually gaps and spaces in which a GPS tracking device can be secured. Of course, if you are working with a vehicle that has metal bumpers, this location is not going to work well for you without an external antenna that can be routed elsewhere.
We have had reports on some high end BMW and Mercedes models that GPS tracking devices do not work well when placed inside the main cabin of the vehicle. After a little bit of investigating, we also learned that many of these customers also have trouble getting their toll tags to work properly. It appears that the manufacturer may have used a material in the construction of the front windshield that partially blocks radio signals, including GPS satellite signals. What’s the solution? In a case like this you will need to either relocate the device outside the main cabin to a location where it has access to a strong satellite signal, or route an external antenna to a good spot.
It’s worth a quick mention that there are tracking devices on the market that use other wireless technologies (such as a mobile phone tower pings) to generate location reports. These devices are getting better, but for now they are still no match for the GPS system. If a location report with an accuracy of a few hundred yards is good enough, then some of the other options are worth a look. But if you need precision, GPS is still the best solution provided that a good antenna location can be found.
In 1966, C. R. “Bob” Brown founded Brown & Associates which grew to become the oldest, most established private investigative agency in the Central, Florida area. Over the years, Bob’s reputation as a professional and compassionate PI grew, winning him many accolades, honors and awards.
He was listed as one of the top investigators in the nation today (P.I. Magazine), which is backed by the numerous awards and recognition he has received, including the National Association of Investigative Specialists’ “Distinguished Service Award”- considered the “Emmy” of the private investigative industry.
Bob also received a “Lifetime Achievement Award” from the Private Investigators Association of Florida and recently received the “Award of Excellence” from City College of Florida. He is the author of “Investigations – Doing It My Way”, a useful book for anyone considering owning / operating a PI agency.
Bob can be reached via email by clicking here.