Parallel and Distributed Processing of Remote Sensing Data on Large Displays

Abstract

A typical LIDAR (Light Detection and Ranging) scan contains hundreds of millions of points. As such, the visualization of LIDAR point clouds poses a significant challenge in data analysis. One solution is to display LIDAR point clouds on a large display wall with an array of LCD monitors. This provides researchers with a high-resolution display environment for looking at and studying large datasets. In this paper, we present a case study that visualizes LIDAR point clouds on a tiled display wall termed HIPerDisplay (Highly Interactive Parallelized Display). It has twenty 24-inch LCDs with a total resolution of 46 megapixels. Interaction between the user and the display wall is achieved by using a video camera system that is able to track the position of a hand-held light ball device. A user holds it to manipulate point clouds on HIPerDisplay. Case studies are conducted to study the LIDAR scans of slopes in the Houshanyue mountain areas in Taiwan. Experiments were conducted to examine the advantages of using the HIPerDisplay for point clouds in data post-processing. The experiments assess two tasks for manipulating point cloud data designed to evaluate the efficiency of the interactive devices. To evaluate the efficiency of the system, a group of thirty graduate students participated in the experiment. User surveys were performed to evaluate the efficiency of the system and to discover the users' opinions about using the interactive device in a large display environment. The results showed that the participants preferred to perform LIDAR data operation tasks on a high-resolution large display environment rather than on a single monitor. The results also showed that HIPerDisplay offered superior performance for the processing of large LIDAR datasets.