η has a value of 180°.
Fig. 19. Method of plotting sector boundaries on the diagrammatic plots. The example employed is the 11:00 to 12:00 P. M. diagram of [Figure 15].
| tan θNpt. = | tan (180° - ψ0) |
| cos Z0 |
Substituting values of
ψ0 found on the form ([Figure 18]):
| tan θNpt. = | tan [180° - (-35°)] | = | tan 215° | = | .700 | = 1.09 |
| cos 50° | cos 50° | .643 |
θNpt. = 47°28´
