Corten, A Survey Navigation System
11
The most important quality of the subject photographed
which determines exposures and development is its maximum
and minimum brightness. We have as yet no instrument to
measure these. In consequence usual procedures are based
extensively on guess.
in the flight elements,
:nown values of other
ions originates a turn,
nk and rate will — in
in ß
I the turn diameter in
its reciprocal are no-
between turn in air,
e conversion factor m
180° + 2 <5
is <5 H sin ô.
9
introduce an angle of
V
= 2 p —.As indicated
e
again be M = mR.
A t.
)tained by means
-turns and of IJ-
ed by a continuously
lously varying rate of
3 can be chosen so as to
t line spacing,
ly but if certain values
m diameter M will not
g A.
ir must be reduced by
lent d = M — A.
r must be extended by
t by means of a U-turn,
rns, both having radius
R, performing a heading change W, and producing a
displacement d, the functional relationship is 2R (1-cos
W) = d.
By chosing R or W in an appropriate way, an S-turn
can be performed to produce the desired line spacing A =
= M — d.
Turn diameter M can be enlarged by inserting an
intermission 1 = At. GS. This is introduced between 2
quarter-turns, thereby forming a U-turn.
Intermission i is made to made up for the difference
A — M, producing the desired line spacing A = M + i.
The figures 3.4.3 illustrate the application of the
approach turns.
3.4.4 Slide rule computation of approach
turns.
Because of the well-known fact that larger survey
missions can be extremely exerting to the crew and also
because a survey crew in the air is constantly pressed
for time, it is imperative that all aspects of flight design
and navigation are well-prepared to simplify the acts of
decision-taking in flight as much as possible.
As a component of this navigation system, we
designed the ITC-Survey Flight Slide Rule, illustrated in
fig. 3.4.4 and described in another publication [7].
Its use facilitates flight design and particularly assists
in computing the approach turns to position the aircraft
