Geodetic referencing of point clouds

Patent metadata

Field	Value
Publication number	US-9594167-B2
Application number	US-201414245799-A
Country	US
Kind code	B2
Filing date	Apr 4, 2014
Priority date	Apr 5, 2013
Publication date	Mar 14, 2017
Grant date	Mar 14, 2017

Abstract

A geodetic surveying method includes deriving surface information for an object and geodetically accurate individual point measuring to at least one reference point. A position reference to an external coordinate system may also be provided by the at least one reference point. The method may also include aligning measurement radiation on the at least one reference point. The method may also include determining at least one direction to the reference point in an internal coordinate system. A method for reference point-independent scanning is also disclosed for deriving the surface information, the method may comprise scanning by continuously changing the alignment of the measurement radiation, determining a respective distance and a respective alignment of the measurement radiation emitted for a distance measurement for scanning points lying within the specified scanning region, and producing a point cloud representing the surface information and having the scanning points, in the internal coordinate system.

First claim

What is claimed is:

1. A geodetic surveying method for referencing a coordinate system of a geodetic surveying device, the method comprising:
deriving surface information for an object in respect to an internal coordinate system of the geodetic surveying device; and
geodetically accurate individual point measuring to at least one reference point, wherein
a position reference to an external coordinate system is provided by the at least one reference point,
measurement radiation is aligned precisely on the at least one reference point and
at least one direction to the reference point is determined in the internal coordinate system when the measurement radiation is aligned on the at least one reference point,

wherein reference point-independent scanning for deriving the surface information comprises:
scanning of a scanning region, specified in respect of the object, by continuously changing the alignment of the measurement radiation;
determining a respective distance and a respective alignment of the measurement radiation emitted for a distance measurement for scanning points lying within the specified scanning region, in particular with a predetermined scanning point resolution; and
producing a point cloud, representing the surface information and having the scanning points, in the internal coordinate system and

wherein referencing of the internal coordinate system in relation to the external coordinate system is made on the basis of at least:
the position reference to the external coordinate system provided by the reference point, and
the specified direction to the reference point in the internal coordinate system, so that at least one orientation of the point cloud is determined in the external coordinate system.

2. The geodetic surveying method according to claim 1 , wherein an absolute position of the at least one reference point is known in the external coordinate system and the referencing is brought about on the basis of the known absolute position of the at least one reference point.

3. The geodetic surveying method according to claim 1 , wherein the at least one reference point is provided in the external coordinate system by at least one of the following:
a geodetically referenced calibration point,
a retroreflector, and
a geodetic surveying device set up with known positioning or alignment.

4. The geodetic surveying method according to claim 1 , wherein a distance to the at least one reference point and a position of the reference point are determined in the internal coordinate system and the referencing is brought about on the basis of the determined position of the reference point in the internal coordinate system.

5. The geodetic surveying method according to claim 1 , wherein, within the scope of scanning, when determining the respective distance and the respective alignment of the measurement radiation, the alignment of the measurement radiation is modified continuously within the specified scanning region.

6. The geodetic surveying method according to claim 1 , wherein, within the scope of referencing, the internal coordinate system is adapted in such a way that the internal coordinate system coincides with the external coordinate system, in particular corresponds to the external coordinate system.

7. The geodetic surveying method according to claim 5 , wherein the internal coordinate system is adapted in respect of position and scaling of the internal coordinate system.

8. The geodetic surveying method according to claim 1 , wherein the internal coordinate system is referenced in relation to the external coordinate system on the basis of further reference information.

9. The geodetic surveying method according to claim 1 , wherein the internal coordinate system is referenced in relation to additional GNSS position information.

10. The geodetic surveying method according to claim 1 , wherein the internal coordinate system is referenced on the basis of an additional point common to both the internal and external coordinate system.

11. The geodetic surveying method according to claim 1 , wherein atmospheric state information is detected and/or geometric measurement information is defined within the scope of the surveying method, wherein
the atmospheric state information and/or geometric measurement information is processed when determining the distance for the respective scanning points and/or when determining the distance to the at least one reference point and there is a distance correction for determining the respective distance on the basis thereof and/or
the scanning points determined within the scope of the scanning are adapted in respect of the position thereof in the external coordinate system, in particular the orientation of the point cloud in the internal coordinate system, on the basis of the atmospheric state information and/or geometric measurement information.

12. The geodetic surveying method according to claim 1 wherein the geometric measurement information includes either particular meteorological data or measurement axis error, and atmospheric state information includes at least one of ambient temperature, air pressure and atmospheric humidity.

13. The geodetic surveying method according to claim 1 , wherein
at least one further instance of scanning of further scanning points,
deriving a further point cloud having the further scanning points in a further coordinate system,
geodetically accurate individual point measuring in respect of the at least one reference point and/or in respect of a further reference point, with determination of at least the direction to the reference point and/or to the further reference point in the further coordinate system and
referencing the further coordinate system in relation to the external coordinate system on the basis of at least the determined direction to the reference point coordinate system, in particular wherein in the further the scanning and the at least one further instance of scanning is brought about from different setup points, wherein the orientations of the respective point clouds are determined in the external coordinate system and hence the orientations of the respective point clouds are determined relative to one another.

14. The geodetic surveying method according to claim 13 , wherein there is at least partial, mutual adapting of positions of the specified scanning points and/or of the further scanning points in the external coordinate system on the basis of the referencing of the internal coordinate system and the further coordinate system in relation to the external coordinate system.

15. The geodetic surveying method according to claim 1 wherein the geodetic surveying method is carried out by and using the geodetic surveying device, wherein the surveying device comprises at least:
one scanning functionality for detecting the scanning points by scanning and producing the point cloud; and
one individual point measuring functionality for highly precisely determining the direction to the reference point.

16. A geodetic surveying device, comprising
a base defining a pivot axis;
a structure which is arranged on the base and can pivot relative to the base about the pivot axis, wherein the structure defines a tilt axis which is substantially orthogonal to the pivot axis;
a sighting unit arranged such that it can pivot relative to the structure about the tilt axis and has an emission unit with a beam source for generating and emitting measurement radiation;
a distance measuring functionality for measuring distances to points;
an angle measuring functionality for measuring

Assignees

• Leica Geosystems Ag

Inventors

• Zogg Hans-Martin
• Kotzur Norbert

Classifications

• G01S7/4817

  relating to scanning · CPC title

• G01S17/06

  Systems determining position data of a target · CPC title

• G01C15/002 Primary

  Active optical surveying means (optical plumbing G01C15/105) · CPC title

• G01S17/89 Primary

  for mapping or imaging · CPC title