Visual Docking Guidance System (VDGS), is a device provided by the airport service to assist a pilot parked the plane on the righr place. On Aircraft parking control activities in the airport, the pilot is assisted by a marshaller that aims to be steering the movement of aircraft to the correct parking spot. The more density of the movement of aircraft on the apron activity requires the use of alternative technology to substitute marshaller, this technology is called Visual Docking Guidance Syatem (VDGS). VDGS display design uses three pieces o f board o f dot matrix display that is made into one to form a combination in accordance with the appearance on the VDGS on the market. Display used is a superbright LED dot matrix. The controller is a three pieces of. PIC 16F84A microcontroller and a series o f shift registers to display the movement of the aircraft to the right, to the left, straight and stops and also display the aircraft identity.

The direction finder of a radio transmitter is a device that functions to find and determine the direction of a radio transmitter that works in the Ultra High Frequency (UHF) band. UHF frequency used is in the range of 420 - 440 MHz. The concept of Doppler radio is used as a method to determine the direction a radio transmitter is located. Radio Doppler use four receiving antennas which are installed at a certain distance so that it can produce a difference in frequency (Doppler) on each radio antenna because of the difference in the angle of the detected signal. The direction of the incoming signal will be displayed on a set of 16 LEDs and each LED will represent the direction of the incoming angle of 22.5 degrees. The detected frequencies are 422,580 MHz and 429,980 MHz originating from the UHF transmitter with 100mW of power and amplified with a radio frequency amplifier of 3 Watts power. The results show that the frequency of 429,980 MHz was detected with a maximum detectable distance of 1500 meters. The frequency of 422,580 can be detected with a maximum distance of 800 meters. This radio direction finder is can be used to find radio signal in UHF band frequency 420-440 MHz. The direction of the radio transmitter location is simply show in group of led’s as a direction detector.