Measurement arrangement for a wind turbine

A measuring arrangement of a wind power installation having a tower and an aerodynamic rotor with at least one rotor blade, the measuring arrangement comprising:

• a measuring device configured to detect a first bending moment of the tower at a first height and a second bending moment of the tower at a second height, wherein the second height is different from the first height, each of the first and second bending moments being made up of:
• a natural moment component, a pitching moment component, and a thrust force moment component;
• and
• a processor configured to:
• compare the first and second bending moments to determine a first comparison value;
• determine a thrust force of the aerodynamic rotor based on the first comparison value determined based on a comparison of the at least first and second bending moments, the first comparison value being independent of the natural moment component and the pitching moment component.