Table II (cont'd)
B8B Publication Plotting Photo Tolerance in |Tolerance in
Bi Country scale scale scale planimetry™, m| altimetry, m
à 1 Norway: |1:25,000^ | 1:/20, 000 1: 30,000
" 145 t 2.5
|] 1; 35,000!
11 1: 50,000 |1: 40,000 and| 1: 40,000 15
"n 1: 50,000 1: 50,000 + 305
A
AM |Switzer- 1: 25, 000- 1: 25,000
31 , 0:3 lot | (1*7 tan «4
1 land 1: 50, 000 | 1: 25,000 1: 30,000 ER id plos tant)
8 1:100, 000
fl
À il South 1: 50, 000 i 18,000 1304000 to Quid mm in 1.5
4 n Africa 1: 36,000 1: 36,000 publication (3 m spot
H scale elevation)
l U.S.A. |1: 20,000 1: 12, 000 0.5 mm in 90% of con-
i to - 1: 60,000 publication |tours within
i 1:10,000,000 1:100, 000 scale 1/2 contour
i interval
MM Figures preceded by the t sign refer obviously to the mean square
| error. Whether the figures listed without signs are always maximum
I errors was not evident from the information supplied.
|
1 Final Drawing of Maps and Systematic Checking of Mapping Accuracy
d
| | : The final drawing of a map is still an operation that consumes a dispro-
d AM portionate amount of energy and money. No major changes have occurred in this
31! field during the period under review. In the final drawing of maps, scribing has
probably been used by the majority of countries, but not too much progress has
been made in direct scribing on the plotters. Some countries have reported that
li they are now experimenting with this possibility.
Two different field checking procedures are used in mapping operations.
hi In some countries field identification is carried out on aerial photographs to
P n replace the actual field check of the plots. By the rigid control of each individual
Mn step in photogrammetric mapping it seems that a large portion of the actual
| accuracy control can be shifted from the field to the office, but on the condition
| that careful field identification be carried out prior to the plotting.
The accuracy control in the field is mostly limited to spot checking.
Information on this phase of the mapping activity and on the final drawing is
summarized in Table III.
nt x