FPV: Technical Area

FPV/RC Terminology


fpv terminology

Here’s a list of terminology that is used in the world of first person view along with explanations:

FPV First Person View
Dbi Decibel Isotropic
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: GPS is used with an OSD to give real time positioning for you aircraft and displays distance by base, altitude and speed.GPS is also required for the RTH feature.
Grid Highest gain antenna, larger and very directional
LOS Line Of SightUK FPV legality states that when flying your plane you must remain in your line of sight or in the spotters.By not seeing the plane would mean you have travelled out of the line of sight.
Mhz Mega Hertz
OSD On Screen Display
Patch PatchA patch panel antenna has a higher gain level of 8/14 dbi.This particular antenna has a longer range and a limited angle of sensitiveness clocking in at 30-40 degrees of view.
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 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 is a built in feature of some not all OSD devices. When signal is lost to your aircraft the return to home function is activated by 3 axis sensors, servo control coupled with GPS and Base GPS coordinates.The aircraft should return home if this occurs.
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


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