ACCURACY OF CLOSE-RANGE ANALYTICAL RESTITUTIONS 367
TABLE 7. MAXIMUM ACCURACY AND NON-METRIC CAMERAS.
Predicted maximum accuracy
for metric cameras
Experimental values (Figures 8, 9, and 10)
TXYZ ' rX- TY 72 ZX M v7 unit: um
Planar 8.7 19 82 19 7.2 15 66 24
Distagon 6.1 21 55 19 5.0 15 44 18
DBA Systems? in a very original way. Long focal lengths (1000 mm), associated with small
angular fields (10° by 10°) and multi-station geometry, seem to eliminate the need for control
nets. The use of long focal lengths provides relative insensitivity to emulsion unflatness and
principal point error. Kenefick® quotes other assorted advantages of the narrow angle, long
focal length cameras, e.g., constant resolution and no problems of variations of lens distor-
tion with object distance. The use of more than two bundles with high convergence seems
to allow precise reconstruction of the object despite the narrowness of the bundles (which
would be impossible with only two bundles if there were no control net). The accuracy
obtained seems to be the same as in the symmetrical case.
CoNCLUDING REMARKS
The results presented here are obviously incomplete and not definitive. I had only two
relatively abundant sources at my disposal for presentation in this report, and in my opinion
these results and other propositions are worth more verification and thorough investiga-
tions, at last for theoretical aims. It is particularly true for the presented predictors, which
should require some refinements. It also would be interesting to estimate the measurement
RMS bias (in fact maximum accuracy) in photogrammetric systems other than the one studied
at the IGN (metric camera plus Gevapan 30 emulsion plus Zeiss Asco-Record comparator).
Finally, the study of accuracy with multi-station geometry is almost a virgin area.
REFERENCES
1. Abdel Aziz and Karara, “Accuracy aspects of non-metric imageries”. Photogrammetric Engineer-
ing, 1974, pp. 1107-1117.
2. Abdel Aziz and Karara, Photogrammetric potentials of non-metric cameras, Civil engineering
Studies, Photogrammetry series N° 36, University of Illinois at Urbana-Champaign, 1973.
3. Bonneval, “Photogrammétrie générale, applications non topographiques”, tome IV, pp. 170-
201, 1972, (Collection de l'IGN, édition Eyrolles).
. Hallert, “Fundamental problems in photogrammetry,” Commission II, Stockholm, 1964.
. Hottier, “Contribution to experimental research on the accuracy of short-distance (7-12 m)
analytical photogrammetry for a pair”. (Ottawa Congress 1972, invited paper by Working Group
V-3).
6. Hottier, “Nouvelle contribution à l'étude expérimentale de l'exactitude de la photogrammétrie
analytique à courte distance dans le cas du couple", 1974. (Société francaise de photogrammétrie,
bulletin n? 53).
7. Hottier, "Analytical photogrammetry with homolog image curves, 1975. (Helsinki Congress, Com-
mission V, presented paper).
8. Kenefick, “Ultra-precise Analytics”, Photogrammetric Engineering, 37:11, Nov. 1971.
9. Meier, “Mathematical models for photographic disposition and their comparison with results of
practical tests”.
10. Wolfgang Faig and Mideya Moniwa, “Convergent photos for close-range", Photogrammetric
Engineering, 39:6, June 1973.
Yi …
APPENDIX À
ESTIMATION OF THE RMS SPATIAL RESIDUAL FROM CONTROL POINTS (AND NOT FROM
CHECK POINTS)
The estimation RXYZ of the “true” RMS residual RXYZ has been defined as
1 n
RXYZ wi > (Xipn — Xir)® + (Yipn — Yir)? + (Zipn — Zi)? (A-1)
: -
