ON THE SIGNAL-TO-NOISE RATIO IN SELF-CALIBRATING BLOCK ADJUSTMENT
: Today, the self-calibrating adjustment with additional parameters has become the most efficient method in the analytical aerotriangulation adjustment. In principle, it is a method to treat the signal (systematic errors) by exclusing the noise (random errors) in the observations. Therefore the signal-to-noise ratio in the obseryations must be an im- portant factor in determining the efficiency of a self-calibrating adjustment. In this paper some investigations about the self-calibrating bundle block adjustment have been carried out by using a set of synthetic data with different signal-to-noise ra- tios. Thus, the reletionship between the efficiency of self-calibration and the signal-to- noise ratio are derived. The conclusions are that in general the additional parameters shoudn't be considered as free unknowns in the block adjustment, but must be conside- red as weighted observations whose weights are to be determined according to the signal-to-noise ratio. In this way, the overparametrization from the interference of noise can be avoided and more reliable and stable results of the adjustment can be obtained. Finally, an approximate method for the determination of the weights of additional para- meters is recommanded.In the appendix the efficiency of a posteriori compensation tech- nique at the diflerent signal-to-noise ratio is given.