About GPS antennas: stationary and automotive, how to make a GPS antenna with your own hands

The GPS antenna is used to determine with special devices the coordinates of the area in which a person is located at a given specific moment. Recently, our country has its own development in this area - the GLONASS system. Modern GPS receivers, without additional clarification systems, have sufficient accuracy to determine location - in the region of 3 meters.

GPS antenna

Tips for choosing an antenna

When purchasing an antenna, you must take into account the technical characteristics of the device, the range of possible signals, the power of the device, location, type of mounting allowed in the car model, etc.

It is necessary to determine the necessary functions:

fixation of radio signals;
determination of television signals (digital or analogue TV);
reception of navigation data (GPS).

The devices can operate to receive one type of signal or function in a complex manner. Multifunctional devices are practical, ergonomic, and save the cost of equipping the machine.

In terms of cost, products fall into the budget, medium and high categories. The choice of antenna is affected by the type of radio for the car. For simple equipment, you can purchase an average-cost antenna. A radio with additional sensors requires a combination antenna. The cost of average quality antennas is 2-2.5 thousand rubles.

It is important to determine the technical characteristics of the device and the signal reception range. Devices can be simple or equipped with a Bluetooth system, the equipment can be combined (GPS/GSM)

Selection includes determining the area for mounting equipment in accordance with the machine model. The determining criterion is the device’s access to the Internet.

It is necessary to pay attention to the equipment included in the device. For comfortable operation, the cable length is taken into account

The element must be shielded, with a large cross-sectional area and the length required for the car model (passenger car, truck).

What does this mean for me?

Despite the simplicity of the scheme, it results in a large number of people having unhindered access to an extremely detailed history of your movements.

For example, the company that makes the fruit juices I give my children knows that I left work an hour early yesterday, and that my wife and I were at the bar on Saturday, and that I was at the medical clinic last Tuesday for 4 hours. The orange juice company knows everything.

Jokes aside? Yes.

Just by noticing that I'm regularly in another office two evenings a week, and that my wife is home with the kids on exactly the same days (yes, she has the same weather app), it's easy to conclude that I'm working a second job .

Although this is not prohibited by my employer, if it becomes known, it could put me in a difficult position, despite the fact that it is my personal time.

I used to think that the chances of such information getting into the public domain, and as a result to my employer, were incredibly small. But now I am not so sure about this, and I think that it may appear on some new site, legally or illegally.

My children also have smartphones. It's good for me to know where they are, but is it right for companies of all kinds to also know which street my daughter is walking down at any given moment, or which rack of hygiene products she's currently looking at in the pharmacy?

Shopping malls are also in play, using both GPS and supposedly free Wi-Fi to track your every move, analyzing who you are and what you buy to get you to spend more.

This list has no end...

Cost of radio antennas

If we talk about the price of the issue, then the cheapest will be a regular whip antenna, which can be purchased in the range of 300-500 rubles. Apart from the SMA connector and a two-meter cable, it doesn’t come with anything interesting.

An active GPS/GLONASS antenna, for example, Beyondoor ANT GPS BY-GPS/GLONASS07, will cost more, about 1,400 rubles. But at the same time, the device is equipped with a built-in 27 dB amplifier and allows you to connect a car radio, navigator or hybrid device.

Another model with the Glonass system is the Shark Fin FM/AM/GPS/GLONASS for 6,000 rubles. In addition to the SMA connector, the device also allows you to connect a DIN plug. But, there is no amplifier in this model, since the signals travel over a wide frequency range with low noise

If the amplifier is important to you, then you can pay attention to another “Shark Fin” V-SMA3M-2FM-TV for 9,000 rubles. With a gain of 4 dB, the antenna produces a decent signal

So what?

Is a person's location data really so sensitive that it's a concern?

For most people, the answer is no, not particularly. Do I really care if anyone knows about my trip to the store, or what route I took?

But what if my destination is a courthouse, a therapist's office, or perhaps a women's clinic?

What if the accuracy is enough to tell who I'm within one/two meters of and for how long?

What deeply personal conclusions can they draw?

Or what if, in order to make ends meet, I work a second job that my employer might not approve of, and my geolocation data shows me to be there all the time?

Do you care now?

What if, instead of an authorized government agency, hundreds of companies of all sizes have access to your data? Each has its own goals and intentions... such as selling or otherwise using your data.

What about the real problems faced by a completely innocent farming family? Or another case of people living in a house in Ashburn, Virginia, where 17 million IP addresses were matched (because there were several large data centers nearby). Recent analysis shows that there are thousands of such "standard" mappings.

Rules for the location of gadgets

When working with any device that performs the functions of a navigator, it is necessary to take into account nuances that can affect the quality of signal reception and transmission.

To ensure that satellite communications are always at their best, you should pay attention to the following factors:

If you notice that the GPS in your car does not pick up satellites, take into account the negative impact of coated glass. This most often happens if you place the antenna directly on the top edge of the windshield, where the frits are located that protect the urethane sealant from ultraviolet rays. The idea of placing a receiving device on the rear window will also not lead to a positive result, but will only aggravate the situation.
The standard GPS receiver built into mobile devices is far from the best solution for navigation, so in any case you will need to use additional equipment with it, otherwise there is a risk of receiving inaccurate location information.

In the first case, the problem can be solved by changing the location of the antenna. If it needs to look directly at the sky, it should be fixed a little lower on the windshield so that it is not located directly on the site of the frits. An excellent option would be to secure the device under the roof. The mortise type of mounting of the GPS receiver allows you to achieve maximum results. To do this, a small hole is made on top of the body from where the antenna is brought out.

A GPS signal amplifier is designed to solve the second problem. Taking into account consumer demand, such devices are equipped with modern communication systems such as USB and Bluetooth. This allows you to save space in the cabin, then there is no need to connect another cable to your tablet or smartphone. The amplifier has a built-in battery and can be charged using a standard mobile phone charging cable. They are also compatible with on-board computers via USB.

How it works?

The position of each satellite can be determined at any time with incredible accuracy. By simultaneously measuring the signal transmission time from several satellites to your device, you can determine the distance at which your device is from each of them, as if you were instantly stretching invisible tape measures.

To do this, simple geometry comes into play - triangulation to determine the position of the receiver on the ground with an accuracy of 2 meters or more. In the future, even greater accuracy is planned, enough to detect whether you change hands while talking on the phone.

In special cases, additional ground transmitters can be installed to improve accuracy to one centimeter.

There are also two other methods for improving the quality of geolocation when GPS is difficult or simply impossible:

A mobile device over a cellular connection can be triangulated from neighboring towers to within 20 meters, and sometimes much more accurately, using increasingly common phased array antennas and so-called multi-beam analysis.
Wi-Fi devices can obtain geolocation from nearby routers, even if they are not connected, by searching for router names (SSIDs) in surprisingly comprehensive databases of known routers and locations.

How to properly install a GPS antenna in a car

Before installation, it is important to determine the optimal location for the antenna. Experts recommend placing the devices on the roof of the car or on other surfaces of the technical equipment.

An antenna located perpendicularly encounters less interference and transmits the signal quickly. It is optimal to place the device under the roof, on the top of the windshield of the car.

The signal from the device on the rear window or in the lower block of the windshield arrives with less intensity, but the device will be preserved better. It is not recommended to place the device near lamps, because reception quality will decrease due to electromagnetic radiation.

The structure is attached in several ways:

magnetic;
overhead (with a clamp);
mortise;
internal.

The magnetic method allows you to fix the device in different parts of the machine. The mount has a budget price, simple installation, does not require openings in the body of the equipment during installation, and reduces the risk of deformation. However, it is necessary to remove the device in parking lots to prevent theft.

It is important to take into account the short length of the receiving dipole, which makes it difficult to determine signals in desert areas

The overhead mount allows you to install the device on the car body using brackets and threaded connections. The device is attached to the rear bumper or drain of the car. An amplifier is not provided in antennas with a surface-mounted type of fastener; it is necessary to take into account the compatibility of the product with the design of the machine.

The mortise antenna is mounted through a hole in the car body (front or rear fender). The opening is treated with a composition that prevents corrosion. The method allows you to hide the mounting pin. It is necessary to regularly process the hole and monitor the integrity of the structure.

Internal installation of the technical device is recommended for GPS modules. The device is placed on the top of the windshield; the surfaces are treated with a special compound before installation. The devices require connection to a satellite signal amplifier and a dedicated power source. The interior antenna is equipped with adjustable gain intensity, does not create noise, does not require complex maintenance and reconstruction of the machine, and has no risk of deformation during operation.

Message formats

GPS data is displayed in different formats via a serial interface. There are standard and non-standard (proprietary) message formats. Almost all GPS receivers output NMEA data. This is a standard for formatting information in strings called sentences. Each one contains different data separated by commas. There are 19 types of such offers in total. Here is an example of an NMEA string received from a receiver that has established communication with a satellite:

The proposal contains the following information:

GMT time: 23:53:17;
latitude: north, 40.039039°;
longitude: west, 10.5125793°;
number of satellites: 08;
altitude: 1577 m.

The data is separated by commas to make it easier to read and analyze by computers and microcontrollers. They are sent to the serial port at an interval called the update rate. Most receivers update this information once per second (i.e., at a rate of 1 Hz), but the best GPS receivers are capable of multiple updates per second. For modern models this value is 5–20 Hz.

Step-by-step instructions for assembling the antenna yourself

To assemble an antenna for a phone or Starline you will need:

arduino mini or arduino nano board;
insulating tape;
piece of wire;
pliers;
soldering iron;
copper wire.

First, the wire is bent with pliers to form a square. Observe the proportions strictly to avoid disruptions in work. The part is then soldered or attached with electrical tape to the patch on the receiver. For soldering, a stranded wire extending from the board is used. Then the device is installed using 2 pieces of double-sided tape.

Before making the antenna, make sure that you can reach the GPS module in the navigator. In Chinese trackers and smartphones, such a connection is easy.

Classification

GPS antennas for car radios are divided into:

external;
internal.

External devices are designed to search for radio and television signals. The device is highly sensitive and is mounted on the outside of the machine. It is necessary to take into account the exposure of the device to precipitation and changes in temperature conditions. The equipment is equipped with an adapter that increases the search parameters for radio frequencies. External devices are attached to the body, trunk, roof, bumper or fenders of the car.

In-cabin devices are mounted on the windshield of a car. The equipment is equipped with amplifiers inside the housing. The device is universal, suitable for different types of car radios, does not require complex installation work, but is very expensive.

An active GPS antenna is a standard device, the system of which is supplemented by an internal signal amplifier. The devices are sensitive, accurately and quickly detect a large number of radio and television waves. The device reduces the amount of interference and noise when playing music and videos.

The functionality of a passive type device depends on the volume of electromagnetic radiation in the area. If there is a small amount of interference, the reception of the radio signal will be stable, but if there are electrical appliances within the range (in cities), the reception accuracy will decrease.

By type of design, devices are divided into:

asymmetrical;
dipole.

A device with an asymmetrical housing is mounted perpendicular to the plane of radio frequency propagation. The equipment is equipped with a telescopic structure, consisting of parts that are unfolded manually or using an electric drive. The antenna includes a pin equipped with a spiral at the base.

Dipole devices are equipped with 2 rods located symmetrically. The devices are mounted in a horizontal position. The type of equipment is optimal for placement inside the car.

Why can't my phone see satellites or lose contact with them?

The reasons for the lack and instability of a phone’s connection with GPS satellites can be external and internal. The former are caused by the influence of environmental factors on signal transmission, the latter by problems with the receiving device itself.

Unfavorable atmospheric conditions (dense clouds), being in a forest or among high-rise buildings. Unfortunately, we have not yet learned how to disperse clouds, but A-GPS technology helps to overcome these obstacles.
The telephone is indoors. To solve the problem, it is usually enough to go to the window or go out onto the balcony.
The phone is in motion, for example while driving. For a cold start of the GPS module, this can be a serious obstacle. To find satellites faster, stop and place the device on a flat surface.

The phone is not equipped with a satellite communication module at all or only has A-GPS, the operation of which depends on the level of the cellular signal and Wi-Fi.
The device has a GPS receiver with a low-power antenna, usually of the film type. In this case, communication with satellites is possible, but it is unstable and highly dependent on external conditions: even the case on the phone can interfere with it. Sometimes the connection only works when the Internet is connected. The problem is usually identified immediately after purchasing the gadget.
The GPS module is faulty. A breakdown (usually damage or failure of the receiver antenna) is detected after a shock, fall or disassembly of the device, although not always. It happens that it occurs for no apparent reason. Manifests itself as a complete or periodic inability to detect satellites and establish communication with them. Or the fact that the signal is received only at a certain position of the phone.
Systemic problems. The source of the problem lies in incorrect settings or faulty firmware of the device.
Incorrectly set system time.
The influence of third-party software or malware. This version is supported by the relationship between the failure and the installation of an application, as well as the presence of symptoms of virus infection.

Installation

GPS module for car radio

A common place to install an antenna is on the roof of a car. This is the first thing that comes to mind for a person who decides to install it himself. But there can be many places for mounting a GPS antenna, and the roof in this case is not the only option.

Let's consider several options:

It is advisable to install the GPS antenna in the upper part of the windshield, facing the sky. Here such an antenna will encounter the least number of obstacles in order to receive reliable reception of signals from the satellite;

On the windshield

The lower area of the windshield can also be chosen as an installation location, only here the antennas will have less potential;
The same effect as the lower area of the windshield will be achieved by installing an antenna on the rear window;
Whatever the disadvantages of the above-described places for installing antennas, they are considered as the most favorable installation options. But installing a GPS antenna near the street lights is a completely bad decision.

GPS module for car radio

So, there can be several ways to mount an antenna; everyone chooses their own option individually. As for the method of fastening, it can also be different.

Understanding the importance of the correct zone for installation is important so that there are no problems in the future. A few words of general information about the principle of operation of the satellite navigator will help to understand a lot:

Each navigation satellite transmits radio signals. They are received, amplified, converted to intermediate frequency, and then further processing continues.

As a rule, the navigator (see 1 din car radio with navigator: device and installation) knows the coordinates of several satellites and the distances to them. But it's not that simple. To solve this navigation problem, it is necessary to determine 4 unknown quantities: these are three known geometric quantities and the offset of the receiver clock;
Interestingly, to increase GPS accuracy, the navigator tries to use as many satellites as possible;
The GPS antenna acts as a component that helps the navigator better receive signals, but even the most seemingly insignificant diffraction effects can be significant.

GPS receiver for car radio

Scheme for receiving GPS satellite antennas depending on installation

As the diagram indicates, the car body is not an obstacle to receiving signals from the satellite. The antenna under the windshield sees and receives the same satellites as on the roof. As for the antenna between the seats, it is only inferior to a couple of satellites. It turns out, in the end, that the geometric factor does not depend on the installation of the antenna? But, not everything is so simple. Only one thing can be said for sure: it is better to install a satellite antenna on the windshield, and not too deep into the cabin.

Types of fastening

GPS receiver for car radio

Satellite dishes can have different types of mounting:

The mortise mount of the antenna involves fixing it through a hole that is made by drilling in the body. In this case, the edges of the holes must be treated with an anti-corrosion substance;
Magnetic mounting means installing the antenna anywhere on the body, depending on your own preferences;
The pin mount involves fixing the antenna to the car drain;
Finally, internal mounting, which involves installing an antenna on the windshield, will require mandatory treatment of the glass with a special liquid.

What is GPS?

Global positioning systems (GPS) consist of a collection of medium-altitude satellites controlled from multiple ground stations.

Each satellite has an extremely accurate clock and sends data and a timing signal to Earth. GPS receivers use these signals to determine your location anywhere in the world in terms of latitude, longitude, and altitude.

Currently, there are three global systems: GPS (USA), GLONASS (Russia) and GALILEO (European Union).

In addition, China has a regional COMPASS system, which it plans to expand to global coverage, and there are independent regional expansion systems operated by Japan and India.

A huge number of devices have built-in GPS receivers, including most modern vehicles, tablets, cell phones and other equipment. These receivers are used to determine the user's location anywhere in the world with impressive accuracy.

For example, a GPS-enabled smartphone app can tell the difference between waiting in line and picking up your order at the counter of a fast food restaurant.

It's surprisingly useful if devices provide location data only to you, but they can also transmit it to someone else.

Adapters

An antenna adapter is used when replacing a car radio with a product of a different brand. The device allows you to reduce the difference in settings and design solutions, and also enhances the quality of searching for radio frequencies.

According to experts, purchasing an adapter is necessary:

when the sound quality decreases, there is interference, noise, distortion in the played video and audio recordings;
when the number of received radio stations decreases;
when the signal in the device periodically disappears;
when the picture on the screen of the radio or video playback device is blurry.

When selecting an adapter for a machine, you must consider:

uniform amplitude-frequency indicators of the adapter;
the presence of a gain of about 15-25 dB;
sufficient height of dynamic range;
presence of low noise figure and high gain.

The designs and dimensions of adapters for passenger cars and trucks may differ.

DIY GPS antenna

There are situations in which, without determining the location, you can find yourself in a very unenviable position. In this case, navigation devices are simply vital. Here, a weak signal from a communication satellite or its complete absence is unacceptable. Then, knowing what a GPS antenna is, you have the opportunity to make it yourself.

An example of a homemade GPS antenna

The figure below shows how you can make the necessary element from scrap materials:

Take a wire, preferably copper, of small cross-section. In our case, 2.5 mm²;
A square of the appropriate size is bent from the wire. The dimensions of the sides are shown in the figure;
We attach the resulting part using soldering or electrical tape (adhesive tape) to the GPS receiver.

As a result of the manipulations performed, a signal acceptable for determining the location coordinates can be obtained.

GPS antennas are indispensable in modern GPS receivers for determining location on the ground. They are very much in demand by tourists who use these devices to correctly plot routes.

Operation setup and connection

After installing the GPS antenna, you need to connect and configure the device. Connects connections with external sources and control wire with marking code AMP-CON. The gray cable with the letter BRAKE regulates the disconnection from watching TV and DVD programs when the car is moving.

You can do the setup work yourself according to the instructions from the manufacturer, which contains software support for the model (OZI, Navitel, IGO). The necessary programs are recorded on the SD card. The IGO8 system requires setting the resolution for the radio to at least 480x234 px.

Then the map is inserted into the device, and the “Options” section is selected in the main GPS menu. In the settings, the required program is selected, the path to the SD card is indicated, and the navigation program is turned on. After testing the settings and operation of the device, the device will determine the location based on geographic coordinates and allow you to connect radio or video

Connecting gadgets

Modern gadgets have a built-in GPS antenna. However, they cannot always be used as navigators. Not in all unfavorable conditions they can pick up a signal from the nearest communication satellite. Such unfavorable conditions include:

Car windows with a coating that interferes with the free passage of signals;
The size of the gadget screen does not always allow you to clearly see all the details of the route;
The overall dimensions of the tablets do not allow it to be placed under the windshield of a car.

When going to a store to purchase the necessary device, it is necessary to explain in great detail to the sales consultant the type of gadget for which the antenna is being purchased, for what purposes the device is planned to be used, as well as what result of use is required, where it will need to be installed.

All this must be taken into account because today's amplifiers use such modern means of communication as a USB port and Bluetooth. For use in gadgets, the latest encrypted data transfer protocol is preferable, because does not imply the need for additional wires that interfere with its use, for example, with a smartphone. However, with this connection it is necessary to very accurately install the antenna in the required location. Computers usually use special USB connectors.

GPS in the car

A modern car requires a navigator built into the on-board computer. Navigation is very convenient for any driver to use.

Car navigator

Designers involved in the design of car navigation systems settled on the following operating algorithm:

An external type device receives and amplifies the signal coming from the satellite. In an enhanced form, it ends up in the navigator;
The received signal appears in the navigation receiver. Based on this, the location of the vehicle is determined. Next, the coordinates are clarified using the system control unit;
After specifying the coordinates of the vehicle's location, the optimal route to the final destination is calculated. This happens on the basis of road maps loaded during the production of the machine. The navigation system is often controlled by voice. If it is necessary to update maps loaded into the car’s memory, use special boot DVDs;
The correct direction of movement is determined using the parameters of the angular velocity of the wheels, which is calculated by the on-board computer.

When setting up a vehicle location on a map loaded into its memory, the vehicle must be at static rest and in the location indicated on the map. In this case, the GPS antenna for the navigation unit is installed at the factory.

How to connect an external antenna to your device

Antenna for car radio

When purchasing an external GPS antenna, you must clearly explain to the seller what device you are buying it for; this must be done, since modern signal amplifiers can be used using a USB port, as well as Bluetoot, namely, you can connect it yourself:

A signal amplifier with a Bluetooth connection is ideal for a smartphone; all parameters will be transmitted using a special protocol, you do not need additional connectors;
PCs and laptops now have a USB/PS2 connector installed, so you can choose an external amplifier to connect through it;
Some tablets do not have a USB input, then the solution is to connect via Bluetoot; the effectiveness of this antenna is achieved by an autonomous power supply and the need to correctly install the antenna mount.

Types of connecting an amplifier to a signal receiver

Types of antennas for radio tape recorders

Today there are many devices for improving the signal, the best of them are car antennas, which can be:

External. Such devices are used to receive television and radio signals. A TV antenna for a car radio is a passive device that is exposed to the environment, but it has a fairly high sensitivity. Because of this, it is necessary to equip the antenna with an additional signal amplifier (adapter). In addition, many note the inconvenience of installing an external device on the car body.

Internal. Devices of this type are active GPS antennas, which are usually mounted on the windshield of a car. The device is equipped with a built-in amplifier and can be used with a wide variety of radio models.

GPS modules are very popular among car enthusiasts. The operating principle of such antennas is to receive satellite signals, convert them into an intermediate frequency and subsequent processing. Internal antennas are connected to the vehicle's on-board system. The main advantages of such devices are: small size, ease of installation, “confident” signal level and long service life. Among the disadvantages, it is worth noting only the rather high cost of such antennas.

When choosing an antenna for a radio, you need to take into account many characteristics, including signal reception range, device power and much more. The place where you plan to install the device is also important.

What's next?

It's interesting to think about how these issues might be impacted by progress or new technologies in the near future. Here are a few things that I think deserve our attention:

Increasingly accurate composite geolocation services can literally determine which pocket your phone is in.
The type of low-power location detection and tracking used by TrackR is built right into the operating system of almost every device.
Longer-lasting and higher-energy batteries can provide longer runtime for trackers.
Richer and finer-grained cellular coverage (microcell and picocell) is able to triangulate using terrestrial signals with much greater accuracy.
A growing variety of applications, including in exciting areas such as virtual reality, are being monetized by selling user data.
More complete databases of mobile devices, routers and owners allow you to compare GPS tracks of different people by place and time.

Remember that the servers these apps send your GPS data to have the inexhaustible ability to preserve your personal trace for a lifetime, possibly for a very long time.

Almost none of it is protected by law, and most are currently extremely vulnerable to hacking because it is not considered sensitive enough to merit even the basic protection afforded to things like credit card information or medical records.

This data will soon be so complete that in 10 years, almost everyone will be able to know where you were last Tuesday at 2:34 p.m., what you were doing and who you worked with, with a reliability far greater than you could possibly possibly do yourself, remember that .