TEST ON JOINT ADJUSTMENT OF GEODETIC AND PHOTOGRAMMETRIC DATA 
Gianfranco Forlani, Luigi Mussio 
Ist. di Topografia, Fotogrammetria e Geofisica (ITM) - 
Politecnico di Milano 
Milano, Italy 
‘ABSTRACT 
The program CALGE, of network adjustment for planimetric or altimetric 
or planoaltimetric geodetic measurements, and block adjustment by 
independent models or bundles for the aerial and terrestrial photogram 
metry, and joint adjustment of geodetic and photogrammetric data, has 
been implemented by the computing team of the ITM in the last two years. 
Direct solution, i.e. the exact Cholesky factorization within the 
profile of the normal matrix and the computation of suitably selected 
elements of the inverse matrix, after the application of a reordering 
algorithm of modified reverse CutHill, McKee type to minimize the 
bandwidth and the profile, is performed. 
The program works with excellent performance for real examples of 
geodetic networks and photogrammetric blocks, of about 10^ equations 
and 5,107 unknowns.- 
Two tests on joint adjustment are performed: the first uses italian 
data collected for a technical map, the second uses the data of the 
joint adjustment Test of the Commission A OEEPE. 
1. THE ITM PROGRAM CALGE 
The computing team of the ITM has developed in the last two years à 
new program on joint-adjustment of geodetic and photogrammetric data, 
as suggested recently /1/, /9/. This program, the first and at present 
the only one .in Italy, is also performed to CALculate GEnerally the 
adjustment of every kinds of geodetic networks (levelling, triangulation, 
transverses, etc.) and photogrammetric (aerial or terrestrial) blocks 
by independent models and bundles. 
Some details on the program CALGE are given in the rest of this para- 
graph; more detailed information can be found in the references /10/, 
/11/. The flow chart of the program CALGE is shown in figure l.l. 
The tangent plane for the planimetry and the local sphere for the altim 
etry are used as reference surfaces. À new program GLOBO (= globe) is 
announced as available in thenext year, using as reference system the 
ellipsoid, where the differences of level are corrected with the ortho 
metric correction and for the geoid ondulation, whereas the azimuthal 
and zenithal angles are corrected for the projection or the component 
of the deflection of the vertical /14/, /4/. On the other hand, the 
transformation from geodetic to map coordinates is a final problem, 
that can be separated from the adjustment. 
The program accepts, as data, real cases and simulated examples. The 
input uses four files for the measurements and the preliminary coor= 
dinates and parameters of the geodetic and photogrammetric data. The 
same arrangement is necessary in the output to save the adjusted co- 
ordinates and parameters and the residuals both with their standard 
deviation. The preliminary coordinates and parameters should be a- 
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