1360 PHOTOGRAMMETRIC ENGINEERING & REMOTE SENSING, 1975 
aerotriangulation solution. The program can accept the following types of observations for 
adjustment: 
® photogrammetric observations: rectangular photo coordinates corrected for lens and film distor- 
tions, exterior orientation parameters of each photo, aircraft altitude above ground at each expo- 
sure, and ground controls in a rectangular (X,Y,Z) coordinates system; and 
® geodetic observations: vector distances, geodetic azimuths, Laplace azimuths, horizontal angles, 
elevation differences, altitudes, longitudes, and elevations. 
The observation equations for the geodetic measurements are derived from equations used in 
first-order geodetic surveying and take into account the curvature of the earth. 
Three different coordinate systems are used in program SAPGO-A for the object space. 
These are: geographic coordinate system (longitude, latitude, and elevation), geocentric 
  
  
X 
Fic.4. Close-range photogrammetry using distances from camera station as 
controls. 
Z 
  
  
X 
Fic. 5. Close-range photogrammetry using distances, angles, and directions as 
controls.