ALT 15
ALT 16
ALT 17
ALT 18
Terrain area illuminated by cm radar bundle
approx« 1°.
Terrain area illuminated by 50 MC laser bundle
approx. 0.4'
Terrain depth illuminated by radar bundle (depends
on topography, vegetation and water table), values
for average terrain^not specifically steep.
Tilt of the radar/laser bundle. Its value is supposed
to be kept below 1° or its influence is supposed to be
corrected in the adjustment phase of aerial trian
gulation.
approx. 1.5% of
flight height
approx. 0.1 °/oo
of flight height
between 0 and 5 m
Performance of altitude functions.
ALT 19 Barometric altimeter height reading, uncorrected
for temp, lapse and local QNH.
( Using the elements ALT 1,2) .
ALT 20 Barometric altimeter height, corrected for
temperature lapse rate and for local QNH.
( Using the elements ALT 1,2, 3,4) .
ALT 21 Statoscope altitude differences,
and 22 (Using the elements ALT 1,2, 7, 8, 9 or 10) as
measured from high altitudes (ALT 21)
from low altitudes (ALT 22).
ALT 23 Hypsometer altitude differences, as recorded
and 24 continuously. ( Using the elements ALT 1, 2, 7, 8,
11 or 12 ) as measured from high altitude
(ALT 23)
from low altitudes (ALT 24)
ALT 25 Airborne profile record, radar APR, ( Using the
and 26 elements ALT 1, 2, 3, 7, 8,11 or 12,13,15,17,18)
as measured from high altitude (ALT 25)
from low altitude (ALT 26)
ALT 27 Geodolite, airborne laser altimetry, combined
and 28 with continuous recording, and with continuous
strip photo positioning (Using the elements ALT
1,2,3, 7, 8,11 or 12,14,16,18) measured from
high altitude (ALT 27)
from low altitude (ALT 28)
approx. 200 m
at low altitudes 4 m
at high altitudes 6 m
with radio sonde 2 m
2.0 m
1.2 m
1.5 m
0. 6 m
3.0 m
2. 5 m
2 m
1.5 m
NOTE: The performance of the APR or Geodolite can be improved
further by partly eliminating random errors: using groups
of reliable points covering two models, the standard error
in APR can be 1... 1. 5 m; with laser application, it can be
expected that standard errors as low as 1 m may be reached, approx. 1.0 m
