Card video device

The maps video device is an accessory for older analog operating radars . It fades in distinctive points and lines such as the position of radio beacons, the course of airways or geographical contours such as coastlines and national borders on the radar screen .

In the past, this information was drawn manually and shown reduced in photo technology on a slide . This slide was scanned with a small oscilloscope tube on which the current deflection beam of the radar screen shone synchronously. The brightness of the oscillograph tube shining through the slide was converted back into electrical impulses by means of an image pickup tube .

Since the slide (about 4 × 4 cm) is very small in relation to the screen size, the contours looked very blurred when using a small scale. Therefore, different slides with different scales were used, which then also had to be switched when changing the scale of the PPI screen.

However, more modern radar devices access digital map material and display the desired information together with the digitized target symbols on a large, daylight-capable plasma screen . The map display can be stored in a read-only memory or implemented using a software solution in the radar data processor .