To meet the increasing demand of high-precision localization in coal mine, a set of underground positioning anchors and tags based on Ultra WideBand (UWB) communication were designed and implemented by applying high-precision wireless transceiver chip DW1000. Asymmetric Double Sided Two-Way Ranging (ADS-TWR) algorithm was used to improve the accuracy of ranging between the anchor and the tag, which effectively suppressed the error caused by clock drift. Aiming at the problem that a large amount of invalid communication was generated by the tag broadcasting request frame when starting the localization in the underground multi-anchor layout, a region determination strategy for tags based on ADS-TWR was proposed, which made a tag communicate with the anchors in its region only. At the same time, region abnormal self-checking and region correction mechanism for tags were introduced to ensure the efficient and stable operation of the system. In the coordinate analysis phase for tags, triangle centroid algorithm was used to further improve localization accuracy based on high-precision ranging and reduce localization processing time. Finally, the experimental results show that the localization accuracy of tags is within 15 cm, which meets the requirement of high-precision localization in underground coal mine.

When the dark channel image dehazing algorithms deal with the bright region without satisfying the dark channel fog priori condition, the estimated transmission is relatively small, and it leads to large deviation from the original image in terms of color, smoothness and texture. Therefore, a feedback regulation mechanism of the dark channel dehazing was proposed. First, removed haze using dark channel prior algorithm and gave the feedback difference of the texture smoothness of haze-free image and the original image, segmented the bright region by using Fuzzy C-Means (FCM) algorithm, and then used the Gaussian function to adjust the transmission of the bright region, made it closer to the actual transmission. Finally, the article got haze-free image by using the adjusted transmission. The experimental results show that the proposed algorithm can effectively deal with the bright region which does not meet the assumptions of dark channel. It also makes the dehazed image's color more accord with the real scene, and its visual effect is also better. This method can improve the robustness of outdoor surveillance system.