Title:RADAR PART 8 : height finding Types 79/B and 281/B [Main Title]
Film Number:ADM 2557
Other titles:
Summary: Confidential film on the application to altitude estimation of the principles of rarefication and the change of phase of reflected wireless waves, by means of a special chart known as a polar diagram.
Description: (Reel 1) Need for height estimation. Amusing cartoon explanations on the behaviour of wireless waves. (Reel 2) Further animations to explain the 'change of phase' of wireless waves reflected by the sea. The combination of reflected and non-reflected waves in different phase cancel each other out at certain points causing breaks in the regular pattern of reflected waves. The strength of waves varies, according to the height of the aircraft, because of the differing angles of the reflected waves in relation to the non-reflected waves, and the resultant differences in phase. (Reel 3) The polar diagram for the 79 and 281B sets, and how to plot it with the aid of a friendly aircraft. Graphics of typical 'blips' on the radar screen. (Reel 4) A successful interception, a flight of Fulmars is guided onto target by an RNVR radar team.
