Standard error of y-parallax measurements 
We assume a nearly flat model approximately orientated in a photo. 
grammetric instrument. 
At the fifteen points of Fig. 3 the y-parallaxes are measured in a way 
appropriate to the instrument. From repeated measurements at each point 
the ‘pointing’ standard error can be determined. 
Fig. 3 illustrates the neat model area. The points 31 and 33 are the nadir 
points of the two pictures of the model. 
The measured y-parallaxes at the fifteen points are denoted pyy, py, . . . py, 
From an adjustment of the y-parallax measurements by the method of 
least squares we obtain the following expression for the sum [vv] of the residuals 
after the adjustment. 
1. Six orientation points, 31, 33, 51, 53, 11, 13 
[vv] = + (2P31 — 2P33 — Ps1 + Pss — Pur + Prs)” 
  
and the standard error of one measurement: p = J [vv] 
1 
2. Nine orientation points, 31, 32, 33, 51, 52, 53, 11, 12, 13: 
[vv] e + (2pa1 — 2Pss — Psi -- Pss — Du pia)* 
+ i (Psi + Pss — 2P52)* + t Da + Das — 2pa + i (Pu + Pis — 2P1)* 
3. Fifteen orientation points: 
f 
[vv] = [pp] - is p]? "T gi + irn + P13— Par + Pas — Pai + Das — Par + Pas 
12 i L 
— Du T Pss f — 36 | 20u T Piso Pas — Psi — Psa — Ps3) 
)2 
+ Da + Poe + Pas — Par — Paz — Pu 
|f s 
— 120m — Pis — Psi + Pss) + Pas — Pas — Pa + Da 
f 
L7 E. Qm + P12 + Pis — Ps — Pasa — Pas d Ps d Pa + Pa) 
1 2 
+ par + Poe + Pas + Par + Pas + Pas | 
zu f» 
10 
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