T xor 
A 
je] Pay Py att yb, so bY) ik 
where.p is the number of photographs on which the point is measured. 
  
either II.2. Termination of Pass Point Selection 
elements There are several approaches which can be utilized to terminate 
the automatic selection of pass points. One is simply to require that 
the number of points to be measured is designated as input which must 
be specified before the data acquisition is begun. This approach is 
n not very flexible, but it could be adequate in some instances. 
In a second approach, the value of v' in equation 13 becomes 
rm smaller as the number of image measurements in the solution increases. 
Omi ting It may be possible to determine an empirical value for v' which could 
int be used for threshold testing. If the calculated value of vi at the 
is, jth stage of the selection process is greater than the v' threshold 
iz value, the selection of measurements continues. If Vi is less than or 
posed equal to the threshold value, the selection of measurements is terminated. 
each Another method is concerned directly with the estimation of the volume 
And, of the hyperellipsoid of the inverted normal equation matrix. It is 
follows. possible that an apriori estimate of the determinant which is proportional 
high to the volume of the hyperellipsoid from the adjustment, is available 
mum 
from many previous solutions with similar types of data. This apriori 
  
value can be compared with the value of the determinant of the inverted