Research on method of eliminating accurately Mechanical resonance frequency of the theodolite by complex notch filter

In this paper, We apply a complex notch filter to eliminate accurately influence of Mechanical resonance frequency on theodolite performance. By comparing magnitude-frequency characteristic of system and notch filter, make two frequency characteristics counteract at the mechanical resonance frequency. Experiments show that the method can eliminate accurately mechanical resonance frequency and improve bandwidth and stability of the theodolite.