Showing papers on "Radian published in 1969"

The solid angle at a point subtended by a circle

Abstract: The solid angle subtended by a circle of radius R with respect to any point is calculated. The solid angle is expressed as a function of the inclination angle θ from the central normal to the circle and the distance λR from the center of the circle. The result is given in terms of tabulated elliptic and related functions. A graph of the solid angle as a function of the inclination angle is given for several values of λ. Several special cases are discussed.

A high precision spectrometer table

Abstract: In this note a novel form of spectrometer table is described. It has easily demountable arms and an incremental accuracy to 10−5 radian.

Implicit beam angle control for a frequency scanning radar system

Abstract: A folded waveguide serpentine transmission line is used as a reference element in a phase-lock loop arrangement for vernier adjustment of programmed frequency steps generated to produce frequency scanning using an antenna arrangement having a beam pointing angle which is a function of frequency. A controllable oscillator such as a backward wave oscillator is coarse programmed in accordance with a voltage staircase, each staircase step corresponding to a discrete beam-pointing angle. The said reference serpentine is designed to be an integral number of wavelengths long at each discrete frequency and corresponding beam-pointing angle. The phase-lock loop instantaneously detects errors from the aforesaid even integral wavelength relationship across the reference serpentine (equivalent to a 2 pi serpentine output) and vernier adjusts the backward wave oscillator frequency to produce accurate locking at a 2 pi radian increment for each frequency step. A