## 4 Experiment Verification  
To further validate the proposed joint decoherence-based AOA and TDOA positioning method, physical verification was performed in a controlled outdoor environment. The experiment employed an interference with a bandwidth of \(B=32.736\) MHz and a center frequency of \(f_{c}=1.5479\) GHz. The calibrated transmission power was \(P_{t}=120\) W, which was equivalent to 10 W of equivalent isotropically radiated power (EIRP) after accounting for the attenuator and antenna gain. The low noise amplifier (LNA) saturation power was \(-30\) dBm, and the actual received power of \(-15\) dBm was measured to be below the saturation level.  
The experiment block diagram is shown in Figure 5 and its verification platform is shown in Figure 6, where the interference source was a programmable GNSS jammer, operating at 1.575 GHz (L1/B1C band), with adjustable transmission power (0-150 W) and bandwidth (32.736 MHz). Four spectrum receivers equipped with high-gain omnidirectional antennas and USRP N310 software-defined radios (SDRs) were placed for conducting semi-physical simulation experiments. Moreover, experimental verification parameter settings were configured as follows: the spectrum receiver positions were given in latitude and longitude as (28\({}^{\circ}\)13\({}^{\prime}\)59.2\({}^{\prime\prime}\) N, 112\({}^{\circ}\)52\({}^{\prime}\)51.0\({}^{\prime\prime}\) E), (28\({}^{\circ}\)13\({}^{\prime}\)44.5\({}^{\prime\prime}\) N, 112\({}^{\circ}\)52\({}^{\prime}\)50.7\({}^{\prime\prime}\) E), (28\({}^{\circ}\)13\({}^{\prime}\)45.0\({}^{\prime\prime}\) N, 112\({}^{\circ}\)53\({}^{\prime}\)09.6\({}^{\prime\prime}\) E) and (28\({}^{\circ}\)14\({}^{\prime}\)00.3\({}^{\prime\prime}\) N 112\({}^{\circ}\)53\({}^{\prime}\)10.1\({}^{\prime\prime}\) E), and the interference source position was (28\({}^{\circ}\)13\({}^{\prime}\)51.3\({}^{\prime\prime}\) N, 112\({}^{\circ}\)53\({}^{\prime}\)01.6\({}^{\prime\prime}\) E), with its distances to each base station ranging from 0.2 km to 5 km.  
Figure 7 shows the measured angular spectrum for Figure 6, which shows that a navigation interference signal of 1.5479 GHz was detected. The spectrum analyzer was set to an 8.62 MHz span, covering a range from 1.57111 GHz to 1.57973 GHz, with a resolution bandwidth (RBW) of 82 kHz and a video bandwidth (VBW) of 8.2 kHz to reduce noise and improve signal clarity. The symbol * in the right image represents that the VBW displayed on the current screen is set under the manual mode. This setup is tailored for monitoring GNSS interference signals, with a focus on detecting interference or evaluating signal quality in the navigation spectrum. Upon detecting navigation interference signals, the joint decoherence-based AOA and TDOA positioning algorithm was implemented on the  
Figure 4: Accuracy of the joint AOA and TDOA positioning scheme and the single interference positioning.  
USRP N310 SDR platform to realize high-precision calculation of the spatial coordinates of the interference source.  
The AOA method yielded interference source position estimates at (28.230917\({}^{\circ}\) N, 112.883778\({}^{\circ}\) E), with a residual error of 0.39 m from the true location. Using the TDOA method, the estimated interference source position converged to (28.23091\({}^{\circ}\) N, 112.88377\({}^{\circ}\) E), with a residual error of 0.25 m from the true location. The proposed joint decoherence-based AOA and TDOA positioning method series estimation yielded (28.23092\({}^{\circ}\) N, 112.88378\({}^{\circ}\) E) with a marginally lower residual error of 0.18 m. It is noted that although only one representative epoch is reported for clarity, multiple repeated trials were conducted under identical conditions. The relative error between the measured positioning coordinates and the simulation-predicted results remained within the 0.6-0.8% range, which further validates the stability and reliability of the proposed approach.  
Figure 5: Experiment block diagram.  
Figure 6: Experiment verification scenario.  
Figure 7: Experiment verification results.