PHOTOGRAMMETRIC ENGINEERING & REMOTE SENSING
September 2016
663
If we assume that products from this imagerywere produced
to have an accuracy label of 10-centimeters according to the
new ASPRS standard, then your recommendation for this
imagery would be to support 1:400 scale map according to
the legacy ASPRS1990-Class I. However, if the products were
produced with an accuracy class of 20-centimeters, then your
recommendation for this imagery would be to support 1:800
scale map according to the legacy ASPRS1990-class I, and so
on.
Table 4. Horizontal accuracy/quality examples for high accuracy digital planimetric data.
ASPRS 2014
Equivalent to map scale in
Equivalent to map scale in NMAS
Horizontal Accuracy
Class RMSE
x
and
RMSE
y
(cm)
RMSE
r
(cm)
Horizontal Accuracy at
the 95% Confidence
Level (cm)
Approximate GSD of
Source Imagery (cm)
ASPRS 1990
Class 1
ASPRS 1990 Class 2
0.63
0.9
1.5
0.31 to 0.63
1:25
1:12.5
1:16
1.25
1.8
3.1
0.63 to 1.25
1:50
1:25
1:32
2.5
3.5
6.1
1.25 to 2.5
1:100
1:50
1:63
5.0
7.1
12.2
2.5 to 5.0
1:200
1:100
1:127
7.5
10.6
18.4
3.8 to 7.5
1:300
1:150
1:190
10.0
14.1
24.5
5.0 to 10.0
1:400
1:200
1:253
12.5
17.7
30.6
6.3 to12.5
1:500
1:250
1:317
15.0
21.2
36.7
7.5 to 15.0
1:600
1:300
1:380
17.5
24.7
42.8
8.8 to 17.5
1:700
1:350
1:444
20.0
28.3
49.0
10.0 to 20.0
1:800
1:400
1:507
22.5
31.8
55.1
11.3 to 22.5
1:900
1:450
1:570
25.0
35.4
61.2
12.5 to 25.0
1:1000
1:500
1:634
27.5
38.9
67.3
13.8 to 27.5
1:1100
1:550
1:697
30.0
42.4
73.4
15.0 to 30.0
1:1200
1:600
1:760
45.0
63.6
110.1
22.5 to 45.0
1:1800
1:900
1:1,141
60.0
84.9
146.9
30.0 to 60.0
1:2400
1:1200
1:1,521
75.0
106.1
183.6
37.5 to 75.0
1:3000
1:1500
1:1,901
100.0
141.4
244.8
50.0 to 100.0
1:4000
1:2000
1:2,535
150.0
212.1
367.2
75.0 to 150.0
1:6000
1:3000
1:3,802
200.0
282.8
489.5
100.0 to 200.0
1:8,000
1:4000
1:5,069
250.0
353.6
611.9
125.0 to 250.0
1:10000
1:5000
1:6,337
300.0
424.3
734.3
150.0 to 300.0
1:12000
1:6000
1:7,604
500.0
707.1
1223.9
250.0 to 500.0
1:20000
1:10000
1:21,122
1000.0
1414.2
2447.7
500.0 to 1000.0
1:40000
1:20000
1:42,244
**Dr. Abdullah is Senior Geospatial Scientist and Associate at
Woolpert, Inc. He is the 2010 recipient of the ASPRS Photogrammet-
ric (Fairchild) Award.
The contents of this column reflect the views of the author,
who is responsible for the facts and accuracy of the data pre-
sented herein. The contents do not necessarily reflect the offi-
cial views or policies of the American Society for Photogram-
metry and Remote Sensing and/or Woolpert, Inc.
“C-factor is a term developed to express the physical
limitations of the mechanical movements of the
analogue stereo plotters and its tolerance to the
variation in terrain relief. It should not be used for
all-digital workflow”
