Satellite communications are a powerful way to keep long-distance communications and stay connected in remote areas, but they're not perfect. Depending on the frequency, there are a lot of atmospheric interference issues that could significantly degrade or completely stop any attempt of breaking through. Whether you're out to sea in stormy waters or faced with a sandstorm, here are a few interference concerns and ways to make do.
How Does A Satellite Two Radio System Work?
Satellite two way radio sets usually communicate on the Ultra High Frequency (UHF) band or Very High Frequency (VHF) band, with more sophisticated handsets having multiple antennas for multiple frequency bands. This is to switch between long range communications with a satellite receiver station or other hop station (a station that relays the signal to another location) if available.
These two radio bands are the industry standard. Their range and wave size allow decent distance depending on which frequency you choose and how powerful the signal gain is, but at the loss of higher potential communication speeds. Keep in mind that communications are more than just voice; many data communications that meet or exceed internet speeds in the dial-up era are on the Extremely High Frequency (EHF) or higher band.
When you use a two way radio system, you and your partner will be using a satellite and its supporting systems as an intermediate party. You're not directly talking from radio-to-radio; the satellite receives information from both radio sets and transfers the voice signal information accordingly.
What Causes Satellite Radio Interference?
Interference is considered anything that blocks or impedes a signal. It could be as subtle as fog in the air between the radio and satellite path, or a competing set of radio frequencies.
Your best communications situation is clear skies that allow your antenna to get proper line of sight with a satellite or hop station. With many automated radio systems, the antenna will track, acquire, and train on a satellite receiver station. This means that a pre-programmed set of destinations can be searched for, found, and followed.
On land, being stationary makes acquisition easier. The antenna won't have to move around as much to stay on task, and can adjust itself when rain, sand, or other atmospheric interference is in the way.
At sea, your tracking situation is more difficult. The ship constantly moves, and so is the satellite. The only simple situation is if you're tracking a satellite hop station, and if you're far beyond the horizon leaving land, the curvature of the earth can block any line of sight to land hop stations.
Dealing With Interference
Is your interference from a temporary storm? You can get around the issue by narrowing your radio wave and increasing the power. This causes the wave to be smaller and "sharper", and gives the signal more strength to "punch" through the interference.
This is achieved by contacting a higher frequency satellite node or hop station and/or increasing the gain. You can't just choose whatever frequency you want; the satellite receiver station has to be listening for that frequency, so make sure to have a usable frequency range saved in a laminated or otherwise weatherproofed protection.
Changing frequencies also relieves interference from signal collision. Two signals on the same frequency will mix with each other, causing both frequencies to lose some potency.
Aim high, adjust your position, and contact a satellite communications professional to get a few alternative frequencies for getting around interference.