Some of the highlights of the new ASPRS Horizontal Accuracy Standards for Geospatial Data are the following:
- Unlimited horizontal accuracy classes:
The new standard was designed to fit any horizontal accuracy requirement no matter what technology, current or future, is used. Table 3 represents the new ASPRS horizontal accuracy classes.
Table 3 The new ASPRS horizontal accuracy classes
Horizontal Accuracy Class |
Absolute Accuracy
RMSEH (cm)
|
Orthoimagery Mosaic Seamline Mismatch (cm) |
#-cm |
|
|
RMSEH = RMSEx 2 +RMSEy 2 RMSEH =Radial RMSE=Circular RMSE=Two−dimensional RMSE of X & Y
- Aerial triangulation results should be twice as accurate as the generated products:
- Ortho and planimetric maps ONLY: RMSEH(AT) = ½ * RMSEH(Map) and RMSEV(AT) = RMSEH(Map)
- For ortho, planimetric maps, and elevation maps: R M S E H ( A T ) = ½ * R M S E H ( M a p ) and R M S EV ( A T ) = R M S E H (DEM )
- Control points for aerial triangulation should be twice as accurate as aerial triangulation:
- For ortho and planimetric maps ONLY: R M S E H ( GCP ) = ½ * R M S E H ( M a p ) and R M S EV ( GCP ) = R M S E H ( M a p )
- For ortho/planimetric maps and elevation maps: R M S E H ( GCP ) = ½ * R M S E H ( M a p) and R M S EV (GCP ) = ½ * R M S E V (DEM )
Table 4 lists common horizontal accuracy classes for geospatial mapping products.
Table 4 Common horizontal accuracy classes for geospatial mapping products
Horizontal Accuracy Class RMSEx and RMSEy (cm) |
RMSEr (cm) |
Orthoimage Mosaic Seamline Maximum Mismatch (cm) |
0.63 |
0.9 |
1.3 |
1.25 |
1.8 |
2.5 |
2.50 |
3.5 |
5.0 |
5.00 |
7.1 |
10.0 |
7.50 |
10.6 |
15.0 |
10.00 |
14.1 |
20.0 |
12.50 |
17.7 |
25.0 |
15.00 |
21.2 |
30.0 |
17.50 |
24.7 |
35.0 |
20.00 |
28.3 |
40.0 |
22.50 |
31.8 |
45.0 |
25.00 |
35.4 |
50.0 |
27.50 |
38.9 |
55.0 |
30.00 |
42.4 |
60.0 |
45.00 |
63.6 |
90.0 |
60.00 |
84.9 |
120.0 |
75.00 |
106.1 |
150.0 |
100.00 |
141.4 |
200.0 |
150.00 |
212.1 |
300.0 |
200.00 |
282.8 |
400.00 |
250.00 |
353.6 |
500.0 |
300.00 |
424.3 |
600.0 |
500.00 |
707.1 |
1000.0 |
1000.00 |
1414.2 |
2000.0 |