| 
At several earlier investigations of photogrammetric accuracy the quadratic mean of the differences bet- Table 
ween geodetically and photogrammetrically determined coordinates in the field were used as a measure 
of accuracy. That was the case at the Oberriet investigations, organized by the ISP and the OEEPE. | 
I 
a R1 : o It : | 
6.51 For that reason and in order to facilitate a comparison between the old and the new results the cor- | 
responding weighted quadratic means were calculated. The results were given in fable 12 A for measure- 
ments in stereoautographs and in tables 12 S and 12 T for measurements in the stereocomparator. They were 
founded on the assumption, that the constant and the systematic errors would be random between models 
in a strip but also that the random errors within every model in a strip would belong to the same population 
(Compare 6.3 and 6.4). The following notations were used: 
"a Vv S ^ 
total error — | const. err.? + system. err.2 + rand. err? 
point error in the plane = V tot. err. X? 4- tot. err. Y? 
point error in the space — | tot. err. X7 t- toL. err. Y? -- tot. ern. Z2 
The point errors in the space may be considered as the most comprehensive measure of accuracy for a 
strip. It mt 
! R9 p . . : : ; ; it MU 
6.52 The extreme values of range for every strip are given in the following table. 
there. 
kenfe 
Table 13. The extreme values of range. that | 
of co 
: X | Y Z the n 
Strip 
Min | Max | Range | Min | Max | Range Min | Max Range Zero 
I | 595 | + 420 | 1015 — 416 + 528 944 — 810 | + 470 1 280 723 T 
11 — 593 | + 730 1323 | :— 400 | + 705 1105 1440 | +1 040 2 480 s 
II - 849 | + 831 1 680 662 | + 742 1 404 1030 | +1570 2 600 tione« 
7. Some final remarks. Tabk 
7.0 It was the purpose of the experiment work Monti di Revóira to make clear the accuracy of a general 
good photogrammetric production, which used several comparable instruments, operators and methods and 
similar photographs. For that reason sets of stereomodels from three different flight heights, which were 
measured in first order stereoautographs, were studied. A small serie. measured in a stereocomparator, 
was also studied. Unfortunately there was no time for studying the accuracy conditions in the overlapped 
area (Compare 1—4). 
7.1 The differences between geodetically and photogrammetri ally determined field coordinates were used 
as a measure of photogrammetric accuracy. These total errors were analyzed as to constant, systematic 
and random error parts. The analysis of error has been reported on earlier (Compare 6). Therefore only 
some special observations and studies will be presented here. 
7.2 The question, whether the standard deviation of the residual errors in the plane at the fitting of a mo- 
del to pass points could be used as a measure of photogrammetric accuracy was studied with the aid of 
| | linear regression of the following primary material. 
P F Oberriet — 1.S.P. »Statistik und Fehleriibersicht> No. 11—13, 17—20. 26—29. 32—33 and 36—37. 
FI 
i L Oberriet — O.E.E.P.E. Photogrammetria. Publications speciales de l'O.E.E.P.E. Numero II. Page 130—132. 
E] 
Lii Bandes 7, 8, 9. 
E * . ... Y * . 
i Monti di Revóira — I.S.P. Strip I and II. 
The following notations will be used. 
& = the standard deviation of the residuals in the plane at the fitting of a model to pass points 
N = the standard deviation of the check-point errors in the plane 
k = the coefficient of correlation (5. €) 
The 
The regression function used, N a * &, where the coefficient a should be determined. ol 
er 
The result was given in table 14. gram