Patent CZ-305470-B6 (CZ)
Title: Method of measuring, processing and using data of terrain digital model for objective evaluation of geometrical parameters of measured objects and measuring apparatus for making the said method
Inventor: PŘIKRYL MAREK
IPC: G01S17/88
Filed: 2014-07-15
Abstract: The invented method of measuring, processing and using DMT data makes it possible to obtain terrain digital models with guaranteed equal height precision relative to an altitude coordinate system at arbitrary point of a measured object, wherein the measurement is carried out in n successive cycles using measuring apparatus instruments, which are at the time of measurement at rest and which move between separate measuring cycles as a unit one after other; whereby n cycles form one measuring stage; where n represents the number of measuring cycles. In each measuring cycle, there is measured a position of a GNSS receiver (221), to thereby determining position of a laser scanner (210). Further, there is measured by means of a GNSS instrument (222) a position of at least one stabilized or non-stabilized identical point; further, there is measured in that cycle altitudes by means of target devices (232) of height traverse of these at least two stabilized as well as non-stabilized identical points using the instrument (231) for altitude sight each as at least one backward sight and at least one forward sight. After finish of measurement, optionally in the course of measurement, the data regarding GNSS receiver (221) position, data regarding laser scanner (210) position and data regarding position and altitude of the stabilized or non-stabilized identical points (252) are stored. In the same time of each cycle, there is simultaneously carried out a detailed measuring of the surface using the laser scanner (210), to thereby obtaining so called cloud of points; and using a land means of conveyance (291) for forward sight, there is successively measured at least one identical point (252) relating to the given cycle. In the next cycle, the entire measuring apparatus is simultaneously transferred in line; the central means (290) to a new point of collection of detailed points, the end means (292) to a new backward sight to the stabilized identical point (252) and the front means (291) to a new forward sight, wherein the stabilization of the identical point (252) is carried out and subsequently to other identical points. In each cycle, there are measured clouds of points of the measured object surface in coordinate system of the laser scanner (210). So obtained data is then stored for further processing into a data acquisition computer (240). After finish of one measuring stage, evaluation of spatial coordinates of the detailed points of the laser scanner (210 takes place wherein spatial coordinates of the laser scanner (210) and positions of the identical points (252) are used. This is then followed by transformation in a global coordinate system to thereby obtaining a final position and orientation as well as approximate height and incline of point cloud of a separate scan position of the laser scanner (210). Subsequently, improvement of data by means of measured stabilized as well as non-stabilized height and incline transformed identical points (252) takes place, in order to achieve higher altitude precision of the output data. Based on the measured data, the obtained and improved data is then processed to a digital model of the characteristic of the measured object, whereby the digital model represents points on the measured object surface with guaranteed altitude precision of the surface at a given measuring time of one stage.