hods of
useful
se of a
ects if
1 on the
| of the
xamining
; their
nits of
desk-top
ins the
nsor was
current
unit for
e relied
ent data
f within
Omm.
use.
tured by
ing all
2-2. Laboratory Testing and Results
Laboratory tests were carried out to determine
the basic characteristics of the non-prism
infrared laser-ranger selected. The experients
implemented and the results attained are as
follows:
[Distance Measurement and Error Characteristics]
A variety of distances within the laboratory were
obtained,and a total of 100 measurements for each
naural object targeted (cardboad) were taken from
the same position in the set mode (continual and
single ) and precision mode (+3,+5,+10,+20mm). An
example of the distribution (dispersal) of the
measurement values is indicated in Fig.l. These
are at a distance of 8.1m in the continual mode
with a precision level of 20mm. The laboratory
tests provided us with information on:
*The subject measurement error of the natural
object can be contained within a range of
approximately 2.5 times the catalog value in each
mode.
*Measurement accuracy relies on the number of
pulse shots,but does not depend greately on
measurement distance.
Table 1. Accuracy Verification Results
Approximate Average (nm) Standard
Distance (m) Deviation(mm)
47m 46.5341 21-3
69m 68.8399 20.9
106m 105.9953 23.5
262m 262.9227 27.3
Precision Mode 320mm
Average 8.1467m ^ Standard Deviation 27. 6mm
8.25
9 o
8.2
h,. O9 o P o o Gà OQ Q
D e®@ ao G qn? o que? CP
= nz c o € & oO a ep oO Gp E
8.15 gd og ^o oUom'^peg $n
S 35 9 o D ode Bo d PE
"t3 i dr e Le eu o un J
D . o o o
i
=
N 8.0 4
a
X:
8
Natural Object Target(Card Board)
Figure 1. An Example of the Distribution
of The Measurement Values
2-3. Field Test and Results
As the laboratory tests were restricted to a
measurement distance of approximately 10m,outdoor
tests were carried out in order to secure a
measurement distance of about 200m. The test were
implemented over variable distances betweem
approximately 40m and 260m, and 100 measurements
over each distance was the target. Accuracy
verification results are indicated in Table.l.
These results are in the continual mode with an
precision level of 20mm. The field tests provided
us with information on:
*Although the measurement distance was alternated
at variable distances between 40m and 200m, the
measurement error levels did not experience large
changes.
*Although a variety of natural outdoor objects
with differing reflection qualities were used
(wood, grass, rocks, etc) there were no
discrepancies in the measurement vallues.
2-4. Identifying Precision
Objects with a large surface area were used for
the rests on distance accuracy measurements as
described in 2-2,and 3. Tests were then carried
out to determine if smaller objects could be
identified. One problem here was the fact that
the beam of the non-prism infrared laser-ranger
used had a diameter of 20cm from a distance of
100m. Dowels with differing diameters
(10,19,25mm) were used as the subjects during the
identifying precision tests, and the measurement
distance was alternated at variable distances
between 60m and 120m . With the fact that the
beam has a diameter of 20cm at a distance of 100m
as a basis, we obtained the relationship between
varying distances and the ratio of the bean
(surface area ratio) on the surface of the
dowels. The results of these tests are indicated
in-Fig-2-
Ratio of area(%)
D a Sp IN
Distance(m)
Dowel (19mm) Dowel (10mm)
@
\
~
NC Ë
—— Ratio of area
-
: Zi fo Meter zn Uu ble to detect
: | ] a A, T
= 3 5
Ne Ratio of area
=
Ratio of area(X)
Ratio of area(X)
0 40 a 120 It) 4t) a 20 18)
Distance(m) Distance(m)
Figure 2. Relationship Between Varying Distance and The Ratio of The Bean
on The Surface of The Dowels
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B5. Vienna 1996
