45 
In the model 7,2 + 1 the coordinates of corresponding points are 
2; = 0 Xs ==0 
(151) 
Ys = d Ys = — d 
For these points the differential formulae (148)— (149) become 
Model ? — 14 
dy, ,;4 — — dd», 4 hd, (152) 
dby», d? d hd d? + h? 
dy; ia = RSR dx, — 2L dbz, + 7 dq, — — d; (153) 
dx; _,;¢ = ddx, -- hdqs; (154) 
dby.. d? 1 d à hd ; d? + M d 
E , — dbz, — — dpa, — ——— ly; 55 
dyi iie = 2 pO + 2 n 1622; p 49s 2] ars (155) 
Model 2,7 4- 1 
di.icis A (156) 
dby,. b d. d 
d9. 13 a ml + y da, , + TE dbz, | 
b2 + h? b\d d? + h? 2 do,, m 
! b 2]h Ce Dur rem qu) 
diini59 (158) 
dbys, b d? d 
dy. sis 5 ig 5 d. 177g; We 07 
p --» b\ d d? + h? : do. I^ 
Eb i SU er weds ie (15) 
At the coordinate transformation between adjacent models the coordi- 
nate differences (70) are used. Consequently the expressions (71) are 
used for the study of the error accumulation. 
  
  
  
SE — — M