## 3 Results and Discussion  
Faults and folds in the ore field generally reflect the lineaments on remote sensing images. By field investigation in the Gaosong ore field, lineaments in the mining area are influenced by surface faults and folds. Two research areas were chosen near the Lotus Flower Mountain fault and the Wuzi Mountain anticline (Figure 14). The strength and density of lineaments extracted both by traditional methods and then by the improved line segment tracking method were analyzed in these two areas. By comparing the variations between the traditional Canny algorithm, the improved line segment tracking method, and the field measurement, the results show that the improved line segment tracking algorithm has more advantages in providing results of lineament extraction. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Input Parameters** & **Value** & **Meaning** \\ \hline Number of lags & 10 & Number of lags for each semi-covariance function \\ Unit lag separation distance & 10 m & Interval distance for each lag \\ Lags tolerance & 5 m & Hysteresis tolerance \\ Azimuth & \(0^{\circ},5^{\circ}\)..., 175\({}^{\circ}\) & Azimuth \\ Az tol & \(10^{\circ}\) & Angle tolerance \\ Bandwidth h & 20 m & Azimuth bandwidth \\ Ndir & 36 & Number of directions to consider \\ \hline \hline \end{tabular}
\end{table} 
Table 1: The input parameters and values required when using GAMV program in GSIIB. Lineament strength and density in the ore field were extracted by Arcgis software. It was used to intercept two circular windows with a diameter of 100 m from the vectorized image, and the lineaments were shown in the circular windows. Two circular windows were located in the side of the Wuzi Mountain anticline and in the Lotus Flower Mountain fault [42]. By using the improved circular scan line method [43; 44], based on the directional semi-variance function tool in geostatistics, the lineament strength density parameters were analyzed to quantitatively describe the spatial variability of lineaments [45; 46; 47; 48; 49; 50]. Then, the spatial variability of the lineaments extracted by the traditional method and the improved line segment tracking method were compared with the measured variability. The measured digital lineament strength and density are shown in Figure 15.  
Lineament strength and density in the same area within the measured region were analyzed when extracted by the traditional Canny algorithm and by the improved line tracking method, respectively. The processing results are shown in Figures 16 and 17. The results show that the lineaments extracted by both the traditional and by the improved line segment tracking algorithm are similar to the measured lineaments by eye. Their lineament strength and density parameters were analyzed by the Arcgis 10.8.1 software. The parameters contain an average value, standard deviation, variance, coefficient of variation, and fracture density (Table 2). From Table 2, we can see that the average lineament strength by field measurement in regions 1 and 2 are 0.5125 m/m\({}^{2}\) and 0.7284 m/m\({}^{2}\), respectively. The average lineament strength by the traditional Canny algorithm and the improved line segment tracking method are 0.3593 m/m\({}^{2}\) and 0.3890 m/m\({}^{2}\); 0.4742 m/m\({}^{2}\) and 0.4563 m/m\({}^{2}\); 1.42 and 1.87 times; and 1.08 and 1.59 times. The average lineament density from measured data in region 1 and region 2 are 0.0886 and 0.1813, which are 1.73 times and 3.02 times, and 0.94 times and 2.03 times of average fracture strength extracted by traditional Canny algorithm and improved line tracking method. The coefficients of variation are 0.87 times, 0.86 times, 0.95 times, and 0.93 times (study area 1), and 0.83 times, 0.78 times, 0.90 times, and 0.93 times for the traditional Canny algorithm and the improved line segment tracking method, respectively. Figure 14: The sampling region in the study area. Figure 16: Digital lineament strength and density map.