|
ENTS,
This afternoon, I did an experiment
with the TruPulse 200. I measured the heights of 20 trees
using the built in tangent-based height routine. I also measured
the same trees using the VD returns to top and bottom - a
sine-based procedure. The following table shows the results. HR
means height routine in the table below. As you can see, the
average absolute difference between the two processes is 8.2 feet.
However, notice the standard deviation and the range. In the
case of the white pine (WP), the tangent method is acceptable, but
falls apart with the hadrwoods. This experiment is consistent
with other tests I've done.
Bob
| TruPulse
Built-in Height Routine Test |
|
|
| |
|
|
|
|
| Species |
HR |
VD |
Diff |
Abs
diff |
| BO |
83.2 |
71.8 |
-11.4 |
11.4 |
| WP |
95.5 |
93 |
-2.5 |
2.5 |
| SO |
70.4 |
64.5 |
-5.9 |
5.9 |
| WP |
103.3 |
103.5 |
0.2 |
0.2 |
| SO |
87.1 |
82.5 |
-4.6 |
4.6 |
| WP |
105.8 |
104.5 |
-1.3 |
1.3 |
| BO |
91.3 |
82 |
-9.3 |
9.3 |
| BO |
88.7 |
96 |
7.3 |
7.3 |
| SO |
84 |
86.5 |
2.5 |
2.5 |
| NRO |
95 |
82 |
-13 |
13 |
| CW |
101 |
97 |
-4 |
4 |
| CW |
105.4 |
98 |
-7.4 |
7.4 |
| NRO |
123 |
90.5 |
-32.5 |
32.5 |
| NRO |
103 |
95 |
-8 |
8 |
| NRO |
106 |
95 |
-11 |
11 |
| NRO |
79 |
89 |
10 |
10 |
| TT |
124.6 |
113 |
-11.6 |
11.6 |
| WO |
74 |
71.5 |
-2.5 |
2.5 |
| WO |
113.1 |
95 |
-18.1 |
18.1 |
| TT |
74.4 |
73.5 |
-0.9 |
0.9 |
| |
|
|
|
|
| |
|
|
|
|
| Average |
|
|
-6.2 |
8.2 |
| STD |
|
|
9.24 |
7.42 |
| Maximum |
|
|
10.00 |
32.50 |
| Minimum |
|
|
-32.50 |
0.20 |
| Range |
|
|
42.50 |
32.30 |
Bob:
These 100 foot white pines might come out OK with the tangent
method, but I doubt that would be the case the 160 footers in
Mohawk. Old white pines have amazingly large crowns and my guess is
that the same problems for height measurement will occur as for the
hardwoods.
Lee
Lee,
Yes, I'm pretty sure you are right. I'm going to
continue gathering data and making comparisons. The trends will
emerge species by specie as short and tall find their places in
the list. The following is an update that adds 8 more trees.
Bob
| TruPulse
Ht Routine Test |
|
|
| |
|
|
|
|
| Species |
HR |
VD |
Diff |
Abs
diff |
| BB |
79.9 |
73 |
6.9 |
6.9 |
| BO |
83.2 |
71.8 |
11.4 |
11.4 |
| BO |
91.3 |
82 |
9.3 |
9.3 |
| BO |
88.7 |
96 |
-7.3 |
7.3 |
| CW |
101 |
97 |
4 |
4 |
| CW |
105.4 |
98 |
7.4 |
7.4 |
| CW |
75.1 |
66.5 |
8.6 |
8.6 |
| NRO |
95 |
82 |
13 |
13 |
| NRO |
123 |
90.5 |
32.5 |
32.5 |
| NRO |
103 |
95 |
8 |
8 |
| NRO |
106 |
95 |
11 |
11 |
| NRO |
79 |
89 |
-10 |
10 |
| NRO |
110.5 |
84 |
26.5 |
26.5 |
| SM |
96 |
90 |
6 |
6 |
| SO |
70.4 |
64.5 |
5.9 |
5.9 |
| SO |
87.1 |
82.5 |
4.6 |
4.6 |
| SO |
84 |
86.5 |
-2.5 |
2.5 |
| SO |
92 |
83 |
9 |
9 |
| TT |
124.6 |
113 |
11.6 |
11.6 |
| TT |
74.4 |
73.5 |
0.9 |
0.9 |
| WO |
74 |
71.5 |
2.5 |
2.5 |
| WO |
113.1 |
95 |
18.1 |
18.1 |
| WO |
81 |
76 |
5 |
5 |
| WO |
85.5 |
89 |
-3.5 |
3.5 |
| WP |
95.5 |
93 |
2.5 |
2.5 |
| WP |
103.3 |
103.5 |
-0.2 |
0.2 |
| WP |
105.8 |
104.5 |
1.3 |
1.3 |
| WP |
86.5 |
86 |
0.5 |
0.5 |
| |
|
|
|
|
| |
|
|
|
|
| Average |
|
|
6.535714 |
8.214286 |
| STD |
|
|
8.97 |
7.40 |
| Maximum |
|
|
32.50 |
32.50 |
| Minimum |
|
|
-10.00 |
0.20 |
| Range |
|
|
42.50 |
32.30 |
ENTS:
Here is the latest table of comparisons
of the built-in height routine for the TruPulse 200 versus using the
Vertical Distance (VD) returns for top and bottom added together.
This test will grow to about 100 trees before it's
completed. But the average absolute distance of between 8.0 and 8.6
feet is likely to hold unless I over-sample hardwoods or confers. If
there is sufficient interest in the test being continued, I'll
develop profiles by species. with other returns added as columns. I
got lazy on the design of this test, but am willing to start over,
putting in a column for distance to trunk, and separate angles
and distances so more detailed anaylses can be performed. The key is
to choose what appears to be the top and measure it via the built-in
routine and then check the results by shooting to the same spots
using the VD returns. The TruPulse is the ideal instrument to
compare measurments taken via the two height techniques, i. e. the
tangent method versus sine top-sine bottom.
If some of you all are interested
in this experiment, maybe you can give me some ideas of what you'd
like to see. I can generate the data and you can assist in the
analysis. Ed, you're a good idea person. Any thoughts?
Bob
| TruPulse
Ht Routine Test |
|
|
| |
|
|
|
|
| Species |
HR |
VD |
Diff |
Abs
diff |
| BB |
79.9 |
73 |
6.9 |
6.9 |
| BB |
113.9 |
76.6 |
37.3 |
37.3 |
| BO |
83.2 |
71.8 |
11.4 |
11.4 |
| BO |
91.3 |
82 |
9.3 |
9.3 |
| BO |
88.7 |
96 |
-7.3 |
7.3 |
| BO |
87 |
87 |
0 |
0 |
| BO |
86.9 |
83 |
3.9 |
3.9 |
| BO |
63.7 |
69 |
-5.3 |
5.3 |
| CW |
101 |
97 |
4 |
4 |
| CW |
105.4 |
98 |
7.4 |
7.4 |
| CW |
75.1 |
66.5 |
8.6 |
8.6 |
| NRO |
95 |
82 |
13 |
13 |
| NRO |
123 |
90.5 |
32.5 |
32.5 |
| NRO |
103 |
95 |
8 |
8 |
| NRO |
106 |
95 |
11 |
11 |
| NRO |
79 |
89 |
-10 |
10 |
| NRO |
110.5 |
84 |
26.5 |
26.5 |
| NRO |
91.4 |
86 |
5.4 |
5.4 |
| SM |
96 |
90 |
6 |
6 |
| SO |
70.4 |
64.5 |
5.9 |
5.9 |
| SO |
87.1 |
82.5 |
4.6 |
4.6 |
| SO |
84 |
86.5 |
-2.5 |
2.5 |
| SO |
92 |
83 |
9 |
9 |
| TT |
124.6 |
113 |
11.6 |
11.6 |
| TT |
74.4 |
73.5 |
0.9 |
0.9 |
| WO |
74 |
71.5 |
2.5 |
2.5 |
| WO |
113.1 |
95 |
18.1 |
18.1 |
| WO |
81 |
76 |
5 |
5 |
| WO |
85.5 |
89 |
-3.5 |
3.5 |
| WP |
95.5 |
93 |
2.5 |
2.5 |
| WP |
103.3 |
103.5 |
-0.2 |
0.2 |
| WP |
105.8 |
104.5 |
1.3 |
1.3 |
| WP |
86.5 |
86 |
0.5 |
0.5 |
| WP |
77.2 |
68.5 |
8.7 |
8.7 |
| |
|
|
|
|
| Average |
|
|
6.852941 |
8.547059 |
| STD |
|
|
10.02 |
8.57 |
| Maximum |
|
|
37.30 |
37.30 |
| Minimum |
|
|
-10.00 |
0.00 |
| Range |
|
|
47.30 |
37.30 |
|