MA 
| | 2 
| 7 Hi | as a function of the ground inclinations and the camera inclinations and the stang fg. 1-9. 
| | T d | errors of the latter. (Appendix D, formulae (21) and (22). ard = 100 
" | D! In order to get an impression of the accuracy of the scale transfer anq the azimut | (= 104 
i | [ UM | transfer under practical circumstances, A ß and Aa (principal point triangulation) m t to à 
of | | 1 TUM mg and m, (nadir point triangulation) were computed for some cases and REN doubt 
a |] 8 the diagrams, fig. 1-7. A p the 
| i | | Each two diagrams on a page refer to the same case; one gives A B and Me, the other " 230 
| 3 | A a and m,. Russar 1 
d 1 | The camera-inclinations used are the same for all cases and indicated in fig. 3a on. Mea 
f i i they refer to an arbitrarily chosen photo-flight of normal quality made in The Neth if scale 
I I | lands by the K.L.M. using a Dakota - plane flying at an altitude of 1600 m. | the type: 
l | i Il For the computation of mg and m, the standard errors in x-tilt and Y-tilt were as. | much m 
i , | | sumed to be 10’. aper wi 
i | | I The diagrams for An and Ma give at the bottom. the profile of the ground along tp, | hain of 
ü 1 P| id axis of the strip. The diagrams for A f and mg give three profiles: besides the profile along The 
N 4 E il : the axis, two profiles parallel to it, containing the outer points of the chain of rhomb; | means à 
| 11 | il | These profiles were read from topographic maps having contourlines, arbitrarily di (meras. 
4 i | Fila from the collection of maps of the Delft Geodetic Institute. | produce 
| || i | The diagrams 8 and 9 refer to more rugged terrain where only nadir point tram. | mall sce 
BH l| | | gulation (m, and mg) is considered. It is emphasized that the vertical scale of the ground | camera lé 
| d | on 1 profile in these diagrams is much smaller (0.36 times) than that of the diagrams 1.7, if 1: 50.0 
i 2 i | The assumed focal distance of the camera, size of the photographs, flying height and The 
1 A | ; i |! scale of the picture are indicated in the description with each figure. The topography | werage t 
i | 4 Hi factor is also given — a conception imaginated by Fagerholm to caracterize the toy. by the K 
i graphy [6] — by which is meant the greatest difference in height in hundreds of meters (My be c 
à occurring within an arbitrarily chosen area of 5 X 5 km2. it altituc 
| The diagrams Fig. 1-9 show also — as a measure of comparison — the standarq | Whi 
: i errors mg and m, for spatial triangulation, formulae for which are derived in Appendix mportan 
i | E: formulae (24) and (26). exception: 
: I | From these diagrams the following conclusions may be drawn: ilustratec 
3 | i T lati 
m | |i i 1. Principal point triangulation (fig. 1-7): the systematic errors Ap and Ag, in scale n: 
1 | | Hi | and azimuth transfer as compared with the standard errors mg and m, in spatial Mi 
| | 1 il i triangulation, are very small for relatively flat terrain with an average topograp | To bb 
i 3 | Lo | | factor up to 0,25. For terrain with an average topography factor up to 1.0 they con P uri 
; e | 4 H | tinue to be smaller, apart from only a few cases where they are somewhat larger. de flight 
! m | | 1 It may seem a little strange to compare systematic errors with standard (acciden- Ono. 
i b | 8 bil 4 tal) errors, but this is justified by the wellknown similarity of accumulation of sy OM 
HL a hi tematic errors and accidental errors [7]. It is emphasized that the really occurring Wh a st 
3 = | | | i | accidental errors may incidentally be as large as two to three times the standard hioduett 
i É | HI error. ümera Ww 
| E ; A 2. Nadir point triangulation: the standard errors in scale and azimuth transfer às | Ame 
ni n 2t M compared with those for spatial triangulation are very small even for hilly country |hlity of t] 
i F4 E. | E with an average topography factor up to 1.0 (fig. 1-7). They continue to be generally ring the 
H 2 E 1 | smaller even for rather rugged terrain with a topography factor of 3.0 (fig. 8 and%). in recent 
4 3 | | On top of these systematic or standard errors come of course the observation iw de 
b 2 | errors. These errors will be the subject of a later paper. Een 
; | 3 - | For a certain type of topography the ground inclination of a radial line is, m Im evi 
a [4 E | average, smaller according to the ground length of the radial line being greater. This I: li an 
UE FU ! length in its turn is greater according to the flying height and the angular coverage ; E 
| | 4 | E the camera being larger. From this it follows that a camera is so much the more suit ps 
d | 8 Fi. for radial triangulation as its lens angle is larger. Tr [16] 
1 | E] i] j This is why we assumed a wide angle or a super wide angle camera in the examples, | 
E DL 14 
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