VSAT Rain Fade

Rain fade is the deterioration of the microwave RF signal levels caused by rain precipitation on either end of the satellite VSAT link. Typically, Ku and Ka band links are affected (frequencies above 11GHz) and can occur at the VSAT remote or the Teleport end of the link. RF energy is absorbed and scattered by […]

Adaptive Coding Modulation (ACM)

What is Adaptive Coding Modulation (ACM)? Adaptive Coding and Modulation (ACM) is a technology which automatically changes the Forward Error Correction (FEC) and modulation utilized on a satellite link to compensate for changes in link conditions, so that it is operating at the most efficient coding and modulation scheme available. Why use ACM? Commonly the […]

VSAT Sun Outages

What is a Sun Outage? A sun outage (or sometimes called a solar transit event or sun fade) happens twice a year during the equinox in March and September, when the Sun is directly above the Equator. Each outage lasts for several minutes for a few days and is caused by the satellite passing directly […]

Relative Azimuth

Relative azimuth is a term used in marine satellite communications. It is the bearing (azimuth) to the satellite referenced from the bow of the vessel in a clockwise direction. The azimuth to the satellite does not change unless the vessel moves location and stays the same as the heading changes. The relative azimuth will change […]

Calculate the Clearance of an Obstruction

If you think you may have a line of sight blockage to the satellite and want to check the distance away from the obstruction (trees, buildings, mast, etc.) you need to be then some simple maths should see you out of a pickle. We can use some simple trigonometry mathematics to calculate the distance we […]

VSAT Link Terminology

VSAT terminology can often be confusing at first but it’s really quite simple and this diagram shows how it relates to the VSAT remote site or the Teleport hub side. The Uplink is always the link to the satellite and the downlink is always the link from the satellite irrespective of which side of the […]

VSAT Frequently used Units

Frequency Hz           Hertz             Cycles per second kHz         kiloHertz       1,000Hz MHz       MegaHertz     1,000,000Hz GHz       GigaHertz       1,000,000,000   Power mW       milliWatt        0.001 […]

BUC Local Oscillator Frequency (LO)

The correct BUC Local Oscillator (LO) frequency is essential if you want to transmit on the correct frequency. Acquiring in to a TDMA network or closing a SCPC link with the wrong BUC LO will be impossible and cause interference to other users in the network. The LO can be found on most manufacturers specs […]

How to find your Satellite FAST!

Need to point your VSAT antenna/dish in a hurry? Here’s how to do it quickly without messing around for hours in 4 easy steps . . . Make sure your satellite modem (receiver) or sat meter is tuned to the correct satellite. Pre-set your polarization (don’t worry about this step if you are using circular […]

VSAT Footprint Elevation Angles

Ever wondered what the white rings mean when looking at a satellite beam footprint map? They are simply the elevation angle to the satellite in 5° increments starting at 0°. Easy to quickly check if the target satellite is above the horizon and what your elevation will be. SatBeams.com is an excellent website for checking […]