Available online
Description
This programme is intended to help students revise key concepts about electromagnetism, waves, and resonance, and is a case study of a new airfield surveillance radar system being developed by Marc...oni. Stuart Freake introduces the programme at the radar station, describing how radar works and ending by asking what the radar signal is. Using animation and a studio set Graham Farmelo describes electromagnetic radiation and the e.l.m spectrum. He then uses a sectioned cavity magnetron to explain how radar waves are generated. Stuart goes on to discuss the problems of designing the best aerial for radar: it needs to be a parabola (as Graham demonstrates with a studio model) and account must be taken of diffraction effects (again demonstrated in the studio using a laser with adjustable slit and computer animation). An array-type military radar is briefly discussed, to introduce diffraction gratings, and finally Stuart shows how the Doppler effect is used to eliminate background "clutter" (from stationary objects) in the radar picture.
This programme is intended to help students revise key concepts about electromagnetism, waves, and resonance, and is a case study of a new airfield surveillance radar system being developed by Marc...oni. Stuart Freake introduces the programme at the radar station, describing how radar works and ending by asking what the radar signal is. Using animation and a studio set Graham Farmelo describes electromagnetic radiation and the e.l.m spectrum. He then uses a sectioned cavity magnetron to explain how radar waves are generated. Stuart goes on to discuss the problems of designing the best aerial for radar: it needs to be a parabola (as Graham demonstrates with a studio model) and account must be taken of diffraction effects (again demonstrated in the studio using a laser with adjustable slit and computer animation). An array-type military radar is briefly discussed, to introduce diffraction gratings, and finally Stuart shows how the Doppler effect is used to eliminate background "clutter" (from stationary objects) in the radar picture.
| Module code and title: | S271, Discovering physics |
|---|---|
| Item code: | S271; 10 |
| First transmission date: | 07-07-1982 |
| Published: | 1982 |
| Rights Statement: | |
| Restrictions on use: | |
| Duration: | 00:25:00 |
| + Show more... | |
| Producer: | Nick Brenton |
| Contributors: | Graham Farmelo; Stuart Freake |
| Publisher: | BBC Open University |
| Keyword(s): | Aerial design; Airfield; Animation; Cavity; Doppler effect; Electromagnetism; Magnetron; Marconi; Radar system; Resonance |
| Master spool number: | HOU3846 |
| Production number: | FOUS233J |
| Videofinder number: | 1789 |
| Available to public: | no |
