71
lowing
2.4).
these
2-1
3014 3016 30
0 5006 3006 ЗОЮ
3043
3040 i°T "
3-2
3066 N 3070
3164 3156
6-5-
7-6
229 1181 “ 3086
Fig. 3c: Elevations Discrepancies AH Between Adjacent Strips
In these values the ground control points used for the block adjustment were
excluded.
From this table it can be seen that M x and M T are nearly equal. This means
that the block adjustment produced a more homogenous planimetrie accuracy in the
block. Before the block adjustment the corresponding standard errors were:
M x = d= 5.6 m, M y = ± 7.8 m.
The planimetrie errors AP = V AX 2 + AY 2 at the test points after block adjust
ment are shown in Chapter VI. In the Figures the test points marked as IQ are
shown by the dashed-line arrows.
From Table III it follows that the planimetrie accuracy of the block triangulation
is sufficient to produce control points for compiling maps in the scale 1:100000 and
eventually even 1:50 000. This means that the goal of this experimental block triangul
ation was acheived as far as the planimetrie accuracy is concerned. This is, however,
not true for the elevation accuracy (standard elevation error M H = dz 9.0 m). This
exceptionally large standard elevation error which resulted from the application of
the aerolevelling method appears to be a result of fairly large errors of the exposure
station altitudes determined from the statoscope data which are obviously not very
accurate. This is substantiated by experiences performed at The Ohio State University
where standard elevation errors of AH = d: 3 m for similar strips were obtained
by using the aeropolygon method. In any event this large standard elevation error
would need further investigation.
The standard errors in Table III refer to a focal length /=100 mm. For a
standard wide angle camera /=150 mm standard errors are to be expected