Attention! Autumn solar interference begins.

Solar interference- distortion of the radio signal received from the satellite as a result of interference with solar radiation. The sun is a star that emits energy not only in the visible (light) part of the spectrum, but also in the form of radio waves. When the receiving satellite dish, the satellite it is aimed at, and the Sun are on the same straight line, the reception of signals from the satellite is impossible: the signals of the transponder are blocked by more powerful noise from the Sun. This phenomenon occurs twice a year: in early spring and autumn. Interference degrades the quality of communication and leads to disruptions.

The sun, like any star, emits energy not only in the visible (light) part of the spectrum, but also in the form of radio waves, including the centimeter range. When three objects - the receiving satellite antenna, the satellite it is aimed at and the Sun - are on the same straight line, reception of signals from the satellite becomes impossible. This is due to the fact that the signals of the transponder are blocked by the more powerful noise from the Sun. This phenomenon is observed twice a year - in early spring and autumn.

Solar interference occurs within 3.5 weeks of the fall and spring equinox (March 21st and September 21st). During these periods, the Sun, making its annual path, crosses the equatorial plane. Solar interference in February, March and April first affects the receiving earth stations located in the northern latitudes, then captures the stations located further south. At the equator, the middle of the period in which solar interference manifests itself falls exactly on the day of the equinox - March 21. Then the interference zone shifts to the southern hemisphere, and the latter are affected by the interference of stations in the southern latitudes. For them, the period of solar interference ends 3.5 weeks after the vernal equinox. In August, September and October, the picture changes to the opposite, since the Sun at this time moves in the opposite direction - from the Northern Hemisphere to the Southern. The interference period for each specific station lasts just over a week. During this period, interference affects every day, at the beginning of daylight hours - for the eastern satellites, at the end - for the western ones.

At first, the interference appears in the form of subtle noises in the image and sound, then day by day the noise becomes more significant, and in the middle of the interference period, the reception is completely cut off. At the moment of interference, especially in clear weather, it is necessary to remove the antenna from the satellite whenever possible. Rolled aluminum reflectors and plastic reflectors with a glossy surface are able to concentrate the sun's rays at the focal point so "successfully" that due to high temperature the plastic parts of the irradiators are melted and the electronics of the converters fail.

The days and times of the beginning and end of solar interference for each satellite for a specific receiving station can be calculated absolutely accurately.

The initial data for the calculation are:

• geometry mutual disposition Earth, receiving station, satellite and Sun;
• antenna gain and main lobe width;
• used frequency range;
• the noise temperature of the receiving system;

The vernal equinox:

Autumn equinox:

The last days of February - the first days of March is the time of spring solar interference for satellite receiving stations of the Urals and Western Siberia... At this time, the Sun, passing its daily path across the sky, for some time finds itself on the line of the satellite - the receiving antenna, "falling" into the directional pattern of the latter. The sun is powerful source electromagnetic radiation in the entire frequency range, therefore, during interference, reception of a signal from a satellite is usually impossible. This phenomenon is observed for 5-12 days, from 1 to 8 minutes every day at the same time. The duration of the interference depends on the diameter of the receiving antenna and the frequency range.

Why solar interference is dangerous

• For receiving systems TV companies and radio stations directly relaying satellite signal on the air: during the passage of the Sun through the directional diagram of the antenna, reception is inevitable - a marriage in the air. To prevent this, it is necessary to prepare an alternative signal source and switch to it in advance.
• For receiving systems using large diameter antennas painted in light color: in clear weather during interference, the sun's rays are focused by the antenna on the converter. Doing so can melt the plastic parts of the illuminator and converter and damage the electronics. To prevent this from happening, it is necessary in advance to place a screen made of cardboard or opaque polyethylene in front of the irradiator.
• For stations receiving signals from satellites with inclined orbits using the intelligent tracking controller RC2000B, RC2000C from Research Concepts Inc .: if the procedure of checking the data of the tracking table is necessary during the interference, the controller can hover over the Sun and "spoil" the table row. This can lead to repeated disruption of reception in a day, even if the interference ends by this time. To prevent this from happening, it is necessary to disconnect the controller from the network in advance for the duration of the interference, and turn it back on after the reception is restored.

How to determine the timing of solar interference

Optimal use of on-line calculator www.satellite-calculations.com/Satellite/suninterference.php. To calculate the interference time, you must enter the orbital position of the satellite (or select a satellite from the list), geographical coordinates receiving station (or select the nearest city from the list - there are several Russian cities there), select the frequency range (C-Ku), season (spring-autumn), enter the antenna diameter in meters, year and press the Calculate button. The program will display the schedule of start time, end time and duration of the interference by day. It can be obtained as a separate html file to print or save to disk, for this you just need to click the Print / Save As button.

The program works for any point on the Earth, however, it is focused on US receiving stations, therefore, when entering data, it is necessary to take into account some peculiarities.

• The orbital positions of the satellites are calculated in degrees west longitude in a circular measure from 0 to 360 W (from the Greenwich meridian to the West). For satellites over the Eastern Hemisphere, you must enter the value of the east longitude with a minus sign, or recalculate the east longitude in a semicircular measure to the west longitude in a circular one: W = 360 - E
• The longitude of the receiving point must also be entered in degrees west longitude in a circular manner. For the Eastern Hemisphere, it is necessary to put a "minus" in front of the value of the eastern longitude, or to recalculate it to the western one using the same formula.
• When entering the antenna diameter, use a period, not a comma, to separate the decimal places. When you enter a number with a comma, the program hangs.
• It should be remembered that Americans write the date: month-day-year, not day-month-year.

On September 27, a period of solar interference will begin in Russia. At this time, the Sun, the communication satellite and the receiving antenna of the ground satellite station line up on the same line, which leads to a deterioration in the quality of reception of TV and radio channels from the satellite, up to a complete loss. Interference is observed twice a year, for three and a half weeks from the days of the autumn and spring equinox (September 21 and March 21).

RTRS uses all available technical capabilities to minimize the influence of solar interference on the reception of TV and radio channels by TV viewers. For communication satellites in different orbital positions, the time of the adverse effect of solar interference is different. Therefore, RTRS branches organize reception of TV and radio channels from backup signal sources in the field. As backup sources can be used as digital packages programs (the federal version of the first multiplex and the second multiplex) and direct broadcast satellites (Tricolor TV, Tricolor TV Siberia, NTV-Plus, NTV-Plus Vostok, Continent TV, etc.) ).

Thanks to reliable work modern equipment RTRS the majority of Russian TV viewers from year to year do not notice the interference.

In the Tyumen region, including the Khanty-Mansi and Yamalo-Nenets autonomous regions, the interference will be observed from September 27 to October 21.

Influence of autumn solar interference on the reception of TV and radio channels in the region

Owners satellite dishes sooner or later they are faced with such a concept as "solar interference". This usually happens in the first year of the antenna's operation, when the provider itself warns users about the possibility of signal loss for this very reason. Let's figure out what it is and why the radio signal transmission deteriorates or disappears altogether.

What is solar interference

Any star, including our Sun, emits not only visible light energy, but also radio waves of the centimeter range. When the sun is in a straight line with the satellite and satellite TV antennas signal cannot be received. All due to the fact that the Sun creates interference, and the signals of the transponder are corny overlapped by noise from the Sun.

When it happens

This phenomenon occurs 2 times a year - in autumn and spring. It is during these seasons that solar interference can occur. Most often, this phenomenon occurs within 3.5 weeks from the days of the spring and autumn equinox. At this time, the Sun makes an annual path, crossing the equatorial plane.

In February and March, the interference first affects earth stations that are located in northern latitudes, then covers more southern receiving stations. At the equator, the phenomenon itself falls on September 21 (equinox). The zone then moves to the southern hemisphere. It is the southern receiving stations that are the last to experience the influence of solar interference, which ends 3.5 weeks after the vernal equinox.

In August, September, October there is a reverse picture, because the Sun begins to move in the opposite direction - to the Southern Hemisphere from the Northern. During this period, for each station, the interference period lasts for one week. Every day during this time, there is interference. Moreover, in the morning, the eastern communication satellites succumb to the influence, in the evening - the western ones.

How does it manifest

At first, if the influence is weak, a slight noise may appear on the TV screen, which becomes strong during the day. At the very peak of solar interference, there is no satellite signal at all. Therefore, you should not worry about this and think that something is broken or the antenna has gone to the side. You are all right, and this phenomenon is completely normal.

What to do

At the very peak of the signal, in the middle of a sunny day, it is advisable to move the antenna off the satellite line altogether. This is done to prevent the plastic parts of the feeds from melting. This can threaten the complete breakdown of the converter electronics. Because of this, aluminum reflectors are very "successful" in concentrating the sun's rays at the focal point.

So in case of detection strong interference or complete loss of satellite signal, check with your ISP if there is solar interference or if the signal is lost for another reason. If this is an interference effect, then go up to the roof (or where you have an antenna installed) and move it to the side. And then let it have to re-direct it to the satellite. It's better than spending money on new converter electronics. Although there are more simple ways... For example, you can simply cover the antenna with something opaque to keep the sun out.

The harm of solar interference

First of all, due to solar interference, radio stations and TV companies suffer, which relay the signal from the satellite to the air. As a result of this phenomenon, they lose the signal, which is fraught with a marriage on the air and a loss of rating. Therefore, all self-respecting companies prepare alternative signal sources and switch to them before solar interference fully takes effect.

The stations that receive radio signals from the Express and Gorizont satellites also suffer. A feature of these satellites is movement in an inclined orbit. Receivers Pansat XR4600D, Drake ESR-700 and ESR2000XT-plus are used to receive the signal. As a result of interference, these receivers can "lose" satellites and start tracking the sun. Therefore, it is necessary to program the receivers for these satellites in advance as stationary and turn off tracking when such a phenomenon occurs. When the interference passes, the receivers need to be re-programmed to these satellites as tilted satellites. All these actions need to be done 2 times a year, and this is an extra cost of effort. However, if not used, then you can simply switch it to Stanby mode for the duration of solar interference.

The stations receiving signals from the Express and Horizon satellites with inclined orbits suffer not least. Sometimes, during the interference period, the data from the tracking tables may be checked. If at this time the controller aims at the Sun, it will spoil the entire row of the table. As a result, repeated interruption of signal reception cannot be avoided even if the interference has already ended on the second day. Therefore, the controller is disconnected from the network in advance and after restoration normal conditions taking it back on. The main thing is not to miss this moment.

Ordinary users who use large diameter antennas can suffer as well. In clear weather, the sun's rays are focused on the converter using this very antenna. The converter heats up and may melt. So it will fail, and the user will have to replace it with a new one. Therefore, watch out for solar interference and when it does occur, either move the antenna to the side or cover it with cardboard or opaque film. Otherwise, the radiation from the sun using the antenna will melt the receivers.

Determination of the interference time

There is special programs for the onset of solar interference. One of them is called Look, and it is distributed free on the web. The program is simple and even primitive, it just shows the exact date when the interference is at its maximum. It also allows you to find out the first and last days of the "session" of the interference. To do this, from the specified date, you need to count the number of days back and forth. The number of these days is also determined by the program, depending on the specified diameter and range of the antenna. But it is worth noting that this program works only with receiving stations in the Northern Hemisphere.

Interference calculator

If you have not found or do not want to download the above program, then you can use the online calculator. It is featured on the PanAmSat website. However, to work with it, you need to have some data.

For example, you need to know the orbital position of the satellite (you can select from the search or enter it manually), the coordinates of the receiving station (you can select your city specified in the list), frequency range, antenna diameter, season. If you have all these data, you need to enter them into the online calculator and click "Calculate". The program will show the start and end times of the interference. All data will be in HTML format, so you can print it and hang it on the wall to always remember it.

Features of working with a calculator

Note that, although this program is focused more on the United States, it works for all receiving stations. However, there are some peculiarities of working with this program:

1. When entering the antenna diameter, you must enter values ​​with decimal places using a period, not a comma. Otherwise, the program will freeze and will not be able to calculate anything.
2. The positions of the satellites are indicated in degrees west longitude from 0 to 360 W (to the west of Therefore, for satellites in the Eastern Hemisphere, you must enter values ​​with a minus sign.
3. Also, don't get confused about dates. In the United States, the date is written like this: "month-day-year". We are used to specifying the date like this: "day-month-year".

Usually this calculator is enough for accurate calculation of the onset of interference and its end. But if you can't figure it out, then visit thematic forums on satellite TV... There are usually topics for determining interference for different cities. Moreover, some providers warn users about the onset of this period and even give advice on how to "get through" it correctly.