
EXTRACTS FROM OFFICIAL PUBLICATIONS
397
Roll-pitch bearing
The bearing error will peak in each of
the four quadrants around own ship for targets on rela-
tive bearings of
045°,
135°, 225° and 315° and will be zero
at relative bearings of
0°,
90°, 180° and 270°. This error
has a sinusoidal variation at twice the roll frequency.
For a 10° roll the mean error is 0.22° with a 0.22° peak
sine wave superimposed.
Beam shape Assumed normal distribution
giving bearing error with
σ = 0.05°
Pulse shape Assumed normal distribution
giving range error with
σ = 20 metres
Antenna backlash Assumed rectangular distribution
giving bearing error ± 0.5°
maximum