Abstract: A method for extracting and analyzing spatial information of a control and protection zone of rail transit with multiple threshold constraints, including the following steps: 1, performing format conversion on a data file and extracting a plurality of coordinate points; 2, selecting key points from the plurality of coordinate points for data simplification to obtain a simplified limit line, a simplified outer structure edge line and a simplified boundary line of construction; 3, programming the simplified limit line, the simplified outer structure edge line, and the simplified boundary line of construction, calling a database, and reading data therefrom for spatial relationship comparison; 4, determining whether the construction of a rail-involved construction project intrudes into a control and protection zone of rail transit according to a result of the spatial relationship comparison, thus completing the extraction and analysis of the spatial information of the control and protection zone of rail transit.

Abstract: The present invention provides a point cloud data acquisition method and device under a situation of no GNSS signal. The method comprises: re-sampling line data acquired from a topographic map to obtain discrete line data; generating a full-second PPS pulse in a simulating manner; counting by using a distance measuring instrument, sampling the count, when it is detected that the full-second PPS pulse is received, calculating position information at a current moment; simulating a GNSS satellite protocol according to the position information at the current moment; parsing the GNSS satellite protocol by using a point cloud data acquisition module to complete time synchronization, and controlling a LiDAR to acquire point cloud data; parsing the GNSS satellite protocol by using an inertial measurement module, and recording attitude determination positioning data in real time to generate POS data; and optimizing the POS data to obtain accurate point cloud data.

Abstract: A method for extracting and analyzing spatial information of a control and protection zone of rail transit with multiple threshold constraints, including the following steps: 1, performing format conversion on a data file and extracting a plurality of coordinate points; 2, selecting key points from the plurality of coordinate points for data simplification to obtain a simplified limit line, a simplified outer structure edge line and a simplified boundary line of construction; 3, programming the simplified limit line, the simplified outer structure edge line, and the simplified boundary line of construction, calling a database, and reading data therefrom for spatial relationship comparison; 4, determining whether the construction of a rail-involved construction project intrudes into a control and protection zone of rail transit according to a result of the spatial relationship comparison, thus completing the extraction and analysis of the spatial information of the control and protection zone of rail transit.

Abstract: The present invention provides a point cloud data acquisition method and device under a situation of no GNSS signal. The method comprises: re-sampling line data acquired from a topographic map to obtain discrete line data; generating a full-second PPS pulse in a simulating manner; counting by using a distance measuring instrument, sampling the count, when it is detected that the full-second PPS pulse is received, calculating position information at a current moment; simulating a GNSS satellite protocol according to the position information at the current moment; parsing the GNSS satellite protocol by using a point cloud data acquisition module to complete time synchronization, and controlling a LiDAR to acquire point cloud data; parsing the GNSS satellite protocol by using an inertial measurement module, and recording attitude determination positioning data in real time to generate POS data; and optimizing the POS data to obtain accurate point cloud data.