More important then the optimum antenna design is the optimum location
The result is the Colinear-Coaxial-Antenna. The unshielded horizontal loops can be replaced by shielded The favorite designs seems to be a groundplane from G-7RGQ ( ) Antenna design requires knowledge, experience and luck.Ī good starting point for antenna discussions is Longer or shorter connection loopsīetween the dipoles can change the elevation angle of the antenna Matching the impedance of the cable (but can be modified by bending the "Dummy-ground" and dipole don't have to touch each other! At least 4 wires (90ĭegree interspaced) should be used (groundplane-antenna). Great, but some radial wires can be used instead. A round piece of sheet metal (13 cm radius) would be Now we need a "dummy-ground", that has to be connected to the shield of Lowest point of this dipole-group has to be connected to the middle Itsĭiameter should be large enough for the necessary stability. They work as 180 degree phase shifter.ĭipoles and loops should be bended from one long piece of wire. Finally the dipoles have toīe interconnected, but upper and lower end of each dipole oscillate Consequently the individualĭipoles have to be placed about each other. Not be an omnidirectional antenna anymore. But if they are placed side by side, then the antenna would To improve the antennas sensitivity multiple electric dipoles can beĬombined.
Such an antenna is an electric dipole and receives Wire or metal stick of 13 cm length, this is the half wavelength of A vertical polarized antenna tuned to 1090 MHz is This is used to draw the radar picture.įor all 4 functional blocks different solutions are available in the
#Planeplotter track by airport Pc#
The PC receives the ADS-B-data and extracts all interesting This data is forwarded to the PC via USB (or RS232). The decoder converts the analog video signal into a digital signals andĭetects inside the received signal-chaos the replies fromĪDS-B-transponders. The receiver selects, amplifies and demodulates the signal. The antenna received the electromagnetic wave, converts it into anĮlectric signals and feeds this through the coaxial cable into the
#Planeplotter track by airport software#
There is no disturbing object in the line of view between aircraft and Linear through the atmosphere and are not reflected by the upperĪtmospheric layers (ionosphere). Receive this transmissions one needs a receiver for this frequency - anġ090 MHz is a frequency inside the L-band. (Automatic Dependent Surveillance–Broadcast)Īll aircraft transponders transmit data at the frequency 1090 MHz. Why should somebody do this? Because it's fun. Thus the virtual radar gives you a good idea about the air Picture with the position (and additional information) of all EverybodyĬan receive this squitter-information and create an own virtual radar (receiver-transmitter, called transponder) and if this transponder isĪ secondary radar ground station is much cheaper then a real radar.Īnother feature is, that the answering aircraft can insert additionalįor several years a new generation of transponders is in use, they Works only, if the aircraft has the necessary hardware Time delay from interrogation to the answer, then it can predictĭirection and range to the aircraft - like a real radar. If the ground station employs a directional antenna and measures the In the aircraft answers by sending a replay back to the ground station. Interrogation to a special receiver inside the aircraft, a transmitter A ground station (interrogator) transmits an Large areas of the US-airspace are not covered by radar. Transponders of threes aircraft had been switched off. Software with PIC18F2550 back to my projects, PIC-Microcontrollers, Electronic, Homepageĭo you remember the 11st September 2001 ? In the USA some aircraftĭisappeared from the screens of the air traffic controllers (ATC).
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