Zur Lösung nichtlinearer Ausgleichungsprobleme bei der Bestimmung von Frequenzen in Zeitreihen With regard to geodesy optimizing procedures for nonlinear adjustment problems are presented. The procedures can be divided into local and global optimization techniques according to the type of the problem. If good initial values are given the usage of local optimization techniques (e.g. the Gauß Newton procedure) is justified. If this is not the case and the minimizing function has various local minimums a global strategy must be implemented. Applying global optimization techniques one will not yield the global solution with certainty; only a probabilistic solution will be obtained. Nevertheless combining local and global strategy and inclusion of all available a priori information a global optimizing system can be established that yields practical results for a wide area of problems. With the increase of the capacity of modern computers the efficiency of global optimization algorithms comes along ...