| are all tho 
ruction of the 
ime of the ex 
the internal 
photogram, and 
oints is known 
image with re 
‚on the photo 
nown. 
vioe, the rela 
al point is 
series of ima 
joint is found. 
ngle 3 pre 
,ernal nodal 
ie angle P. 
‚sfied, the an 
inning angle y: 
> or a band of 
irection", is 
indrical or 
blems presented 
only to speoi 
s of the direc 
TION OF THE 
ramic camera 
the bundle of 
e shall suppo 
‘irst necessa 
the photogram 
she photogram 
mation (see fi 
illel to the 
Mn. 
cylinder in the 
directrix can 
es its position 
    
photogram for 
  
   
  
  
   
  
  
   
   
  
  
   
   
  
   
  
any value of the scanning angle. In addition it is necessary to knows 
a) the value of the amplitude I of the sinusoid defined in (1.3); 
b) the value of the angle X to which the couple of marks (or one of the cou 
ples) indicating the direction of the diretrix of the cylinder, is re 7 
ferred; > 
c) the position for that value of Ÿ of the internal nodal point. In particu 
lar, it is sufficient that the pair of marks and the parameter a be given, 
for example, in correspondence to J z 0. It is obvious that such parame 
ters can be given for “= x or X= - T It is evident that with such in 
formation and with the sinusoidal law of displacement assured, the posi 
tion of the nodal point can be reconstructed (in particular the plane of 
the directrix in which it is contained) for each image that appears on 
the photogram and defined in its position by a value of ß equal to X 
(when the conditions of adjustment are satisfied). 
2.3 - INTERNAL DIRECTION TANGENTS. 
In order to avoid confusion we shall call cylindrical photogram the pa 
noramic photogram located in space on a cylinder of radius p and developed 
photogram the same photogram laid on the plane. 
We make reference to the positive of the cylindrical photogram (see fi 
gure 3), and we assume the direction of the scanning relative to the direction 
of flight as in the figure. It is necessary to point out that the displace 
ment of the IMC with respect to the positive has the same direction as the 
direction of flight (see note at the end). 
We assume as & reference system for the cylindrical photogram a system 
having origin in the position that the perspective point O has for ¥=0, te 
axis x coinciding with the axis of the camera previously defined, and the 
axis z contained in the scanning plane X= 0 (figure 4). The position of the 
axis z is an arbitrary one, and no inconvenience would derive from having 
the axis z in plane in which x # O. Taking into consideration that as tertia 
ry rotation «) has been chosen the rotation around the axis x, it would only 
bring as a consequence a variation of the parameter ©, given by the compu 
tation of space resection. The identification of the plane X= O is necessa 
ry in order to identify the position of the IMC during the scanning, but it 
has no importance in the definition of the plane xz of the reference System. 
With respect to this internal system, the image of a point is defined by 
the three coordinates x, y, Z, the position of the perspective centre C, 
taking into account the signs attributed to y, by the coordinates x, = 
= I ginny, ÿ = 0; 2, = 0. 
The infernal afrection tangents are therefore: 
x-x, x-1 sin X 
  
  
t = = 
x Z- Z 
C 
I y 8 
t = S uua + = — 
y Z- Z Z J