es bet- Table 14. The dependance between the standard deviations of the checkpoint errors in the plane and of
casure the residuals in the plane at the fitting of a model to pass points.
| N : Number of
'Or- | Negative b e
le Col | Test work gan pass- Coefficient a of the Coefficient
'asure- Objective Plate-film mo- points heck regression function of
dels per GEN n=—a correlation
y were
) model
nodels
ılation Oberriet-ISP P 9600 7 5 821 1.09 — t - 0.011 0.969
: Aviogon P 14 000 6 5 1 054 1.37. :::t - 0.011 0.984.
P 21 500 2 5 296 1.16 -- t - 0.026 0.999
Oberriet- P 9600 12 5 2 225 1.01 2- t - 0.203 0.963
OEEPE P 14 000 17 5 4 554 1.23 = t - 0.095 0.982
Aviogon P 21 500 5 5 1321 1.26 t- 0.373 0.922
Monti di P 9000 16 6— 9 933 0.92 +— t - 0.141 0.862
Revôira — P 9000 22 9—11 1504 1,20 — t - 0.107 0.933
ISP
; Aviogon
for a
It must be concluded, that there is a strong dependance between the studied standard deviations. However
it must also be stated, that the coefficients of regression have a large dispersion. The regressionfunction
therefore could give only a rough information of photogrammetric accuracy. Forstner indicated (» Der Strec-
kenfehler bei photogrammetrischer Koordinatenmessung». Bildmessung und Luftbildwesen 1955. Seite 65.)
that the standard deviation of the residual errors at the pass points was dependant on the chosen formula
of coordinatetransformation and to some degree alsoon the number and the position of pass points. If
the number of unknowns of the transformation equations was large enough the residuals could become
zero and the standard deviation also zero and so be of no value as a measure of accuracy.
7.3 The total errors of the experiment work Monti di Revôira will be compared with the old results, men-
tioned in 7.2 but also with the preliminary results given by the Sub-Commission IV:4 of the ISP.
Table 15. Comparison between the quadratic means of the total errrors, obtained at some experiment
eneral works concerning photogrammetric accuracy with first order stereoautographs.
s and
A : Ouadratic mean mm
| were Experiment work
rator. Camera, negative scale etz. X Y Z \ Xilys
apped
Sub-Commission IV:1
ISP. Monti di Revóira 1958 —1960
used Strip I RC7a 10/15 cm, vertical, plate 96 121 194 154
matic 1:9 000
: Strip IT RC5a 11.5/18 em, vertical, film 114 186 256 218
only 1:8 000
Strip III 2RMK 21/18 cm, convergent 161 174 273 237
film
1:7 000
a mor Sub-Commission IV:4
id ol (from vertical parallaxes)
ISP. Monti di Revoira 1958 —1960
Strip I RC7a 10/15 cm, vertical, plate 120 120 160
1:9 000 (122—264) | (712—264) | (96—350)
Strip II RC5a 11.5/18 em, vertical, film 100 100 133
432 1:8 000 (60—220) | (60—220) | (80—292)
ges Significance —level 1 95
ISP Oberriet 1954. —1956 |
RC7 10/15 em, vertical, plate : 161 134
1:9 600
0.E.E.P.E. Oberriet 19541958
RC7 10/15 em, vertical, plate 68 80 217 105
1:9 600 65 87 153 109
84 110 227 138
The results of the experiment work Monti di Revôira seem to be practically the same as the ones of the
Oberriet test. It might be concluded, that the height differences of terrain hardly influence upon the photo-
grammetric measuring accuracy.
17