 Theoretical discussion and field tests illustrate their feasibility and equivalence in overall positioning performance, which have the maximum horizontal position drifts  less than 2\% of the total travelled distance.
<clarity>  Theoretical discussion and field tests illustrate their feasibility and equivalence in overall positioning performance, which have the maximum horizontal position drifts  less than 2\% of the total travelled distance.
 Theoretical discussion and field tests illustrate the feasibility and equivalence in overall positioning performance, which have the maximum horizontal position drifts less than 2\% of the total travelled distance.