INVESTIGATIONS INTO THE EFFICACY OF SIMULTANEOUS PHOTOGRAMMETRIC AND GEODETIC DATA ADJUSTMENT APPROACH

Abstract

The efficacy of simultaneous photogrammetric and geodetic data adjustment (SPGA) approach for the genera-tion of points using analytical photogrammetric tech-niques under various conditions has been investigated in the present work. This approach is an improvement to the basic simultaneous adjustment approach which allows for the general simultaneous adjustment of photo-grammetric and geodetic data. To have a qualitative and quantitative idea of efficiency of the SPGA approach, the sequential adjust-ment approach has also been studied side-by-side. For this, software package SPGA for simultaneous phtogram-metric and geodetic data adjustment approach and package POLYCAM for sequential adjustment approach were used. The required data for investigations was generated mathe- matically'. The investigations with mathematically geneiated data were carried out considering effect of number of control points with different configurations. Also, to assess the capabilities of the adjustment approaches, errors of different -magnitudes were intro-duced randomly in the photogrammetric data, geodetic data or in both, and a comparison of the adjusted coordi-nates with the known ground data was made which obviously would reflect the efficacy of a particular approach in adjustment of error in photogrammetric and geodetic data over the other. The results have indicated that simultaneous photo-grammetric and geodetic data adjustment approach of analytical generation of points may be considered to be more efficient in adjusting the errors in photogram-metric and geodetic data over the sequential adjustment approach and thus should be preferred for generation of control data.