(color online) (a) The detected magnetic field strength is set to 10 Gs. Each simulated azimuth angle ϕ (5°–85° with 10° intervals) with error bar is obtained from corresponding formula with repetition cycles 10. The mean value of each cycle was obtained from 60 groups of random numbers and , which are limited by linewidths and δΔ = 26 kHz, respectively. (b) As an example, the statistical distributions of simulated measurement of ϕ are demonstrated with θ = 60°±0.2°. (c) With the increasing magnetic field strength, relatively higher angle resolution of ϕ could be achieved. The searched target azimuth and polar angles are set to ϕ = 65° and θ = 20°, respectively. Notations are defined in the main text.