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Let's define what is meant by inroute and outroute transmissions:

Inroute transmission - This is everything transmitted by your VSAT, to the HughesNet NOC. It is characterized by Co-Pol and Cross-pol.
Outroute transmission - This is everything received by your VSAT, from the HughesNet NOC. Outroute performance is characterized by Signal Quality.
Defining Polarization
The HughesNet VSAT antenna transmits and receives signals in two linear polarizations: horizontal and vertical, as shown in the figure, above.

The first thing to keep in mind when talking about linear polarization, is that the electric field's orientation describes the polarization. The electric field radiates off of, and is in the same plane, as the "radiating antenna" in the transmitter. The magnetic field is induced by, and is perpendicular to, the electric field. Also, remember that the antennas on the satellite are oriented with respect to the earth at it's meridian or line of longitude. So vertical for the satellite may be skewed from our point of view. These points also hold true for the LNB, only the inroute signal excites the "pickup antenna" in the LNB.

When we adjust the skew or polarization, the little radiator assumes the polarization that we set.

The transmit cross-polarization component can interfere or "disturb" the receiving co-polarization signal, and vice versa. These disturbances need to be kept to a minimum, by proper pointing of the dish. Every antenna has some parasitic cross-polarization. The goal is to have a cross-pol component that is as small, as possible.

Circular polarization is also shown, but is not used by HughesNet and will not be discussed further. Satellite TV uses circular polarization.

Pointing the Antenna and Fine-tuning
After each move, the antenna is redeployed , by first making sure that the mast for the dish is plumb, with respect to gravity. Then, the skew, azimuth, and elevation are set on the antenna assembly, per the values provided by the HughesNet modem or DSSatTool.

After locating the satellite, the azimuth and elevation are then adjusted, with the help of an electronic pointing device, such as a OPI meter or a Birdog meter, to achieve the strongest possible received signal. If your mast is plumb AND you have optimized your receive signal, you are likely to also have an optimized co-pol signal and a minimized cross-pol.

From : Satellite Mobility Support Network (SMSN) HughesNet User Guide

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