Terminology

Here is a list of terms commonly used in FPV. It will help to demystify some of the things that you may read. If you have any questions come into the forum and we will help and advise you. If you have any suggestions on additions to the list or corrections then please let us know.

FPV First Person View
Dbi Decibel Isotropic
Diversity Tracking Diversity Tracking
A dual receiver system that monitors the RSSI signal strength and picks between multiple antennas to display the best picture possible
Ghz Giga hertz
GPS Global Positioning System
Used with OSD`s to give real time positioning of your plane and used to display distance from base, altitude, speed and to guide plane home if RTH feature is engaged and antenna tracking using multiple satellites.
Grid Highest gain antenna, larger and very directional
LOS Line Of Sight
in the UK legally when flying your plane you must still remain in your line of sight, or the spotters. If you cant see the plane you have gone too far
Mhz Mega hertz
OSD On Screen Display
Patch Patch
A higher gain panel antenna normally 8 / 14 dbi, longer range but limited angle of sensitivity 30 – 40 degrees of view
Polarization Polarization
A matched polarized signal has both the transmitter and receiver signals matching in pattern having a large cross section of the signal returning to receiver and providing a great picture. Once a plane backs and / or polarization of the signals don’t match very well the intersecting cross section is small and gives a low quality or no picture.
RSSI Received Signal Strength Indication
Voltage signal to enable signal strength monitoring, many receivers both radio and video have a RSSI pin on the board, this can be exploited and used to indicate signal strength normally displayed in a percentage to indicate strength or packets of data lost. The higher the packets lost the high the chance control or picture degradation will occur
RTH Return to home
Return To Home is a feature built into some OSD devices which when too many packets of radio data are lost assumes no signal to plane and uses 3 axis sensors and servo control coupled with GPS and knows Base GPS coordinated to guide the plane back to you to hopefully regain control
Rubber duck / Whip Refers to an Omni antenna. Usually stated as a 3dbi gain antenna but is really closer to 2.14dbi
Vario Variometer
Sometimes built into a OSD, somethings a stand alone unit used to display or audibly indicate the planes angle of attack and rise and sink rate useful with sailplanes and gliders in general
Vtx Video Transmitter
Yagi A even higher gain antenna, normally 18 dbi but even more directional

Note: Misconception of multiple antenna, some people are under the impression you have to use an omni antenna along with a patch because the patch is directional. But this is wrong, the patch`s pattern even though directional can see behind it to a degree and can just be used by itself although the omni would give greater rear reception

A Video about antennas etc – very informative.

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