PPI (Plan Position Indicator) Radar Disply

This is the my simulated display taken from the 162 Indicator unit. In all respects it is almost identical to that which the Navigator would see.

(To see the correct radial scan, please wait for data to fully download)

The simulation is achieved by painting a map of an imaginary coastline onto a disk with the sea black and the land white. A photo sensor scans a line across the disc from centre to edge and the information picked up is used instead of an actual radar signal.

The disc is mounted onto a magslip (type of rotary transformer) that is rotated at about 1 rev/sec. The magslip provides signals that rotate the trace on the tube, the same as an original H2S scanner. Grass (term used for electrical noise signal) and ground echoes are also added to the signal to make the simulation more accurate

A radial ring about 35% out from the centre of the display is the range marker. As the range knob on the 207 Switch Unit is turned the ring can be moved out or in. By positioning the ring over a target the range can be then read off on a calibrated dial attached to the range knob. The Master compass provides an electrical signal to automatically hold the map display 'north up' (Bomber Command only) and a course marker, which gives the direction of flight of the aircraft, can be seen at about 12.30 on the display.

Return to Home Page

More Pictures?