Modularized laser-based survey system

• US 5,949,529 A
• Filed: 10/28/1998
• Issued: 09/07/1999
• Est. Priority Date: 08/26/1997
• Status: Expired due to Term

• Current Assignee: Kama-Tech (HK) Limited
• Original Assignee: Laser Technology Incorporated (Laser Technology)
• Inventors: Dunne, Jeremy G., Zykan, Blair J.
• Primary Examiner(s): Hellner, Mark
• Application Number:
  US09/181,360
• Time in Patent Office: 314 Days
• Field of Search: 356/4.01, 356/141.2, 356/147, 33/1 CC
• US Class Current: 356/4.01
• CPC Class Codes: G01C 15/002 Active optical surveying means optical plumbing G01C15/105
• CPC Class Codes: G01S 17/10 using transmission of interrupted, pulse-modulated waves determination of distance by phase measurements G01S17/32
• CPC Class Codes: G01S 17/86 Combinations of lidar systems with systems other than lidar, radar or sonar, e.g. with direction finders
• CPC Class Codes: G01S 7/4813 Housing arrangements

Abstract

A modular laser-based surveying system is disclosed which comprises a laser-based distance measuring module and a separable compass module removably coupled to the laser based distance measuring module. Each of these modules may be operated as stand alone units as each has its own power supply and display. The system further may comprise a separate angle encoder module adapted to be coupled to either the laser distance measuring module or the compass module and a data logger or computer for processing data transmitted from any or all of the modules.

Claims

1. A modular surveying system comprising:

a laser based distance measuring module having a hollow housing containing a transmitter for transmitting laser pulses toward a target, a receiver for receiving reflected laser pulses from said target, a processor connected to said transmitter and receiver for determining from said transmitted and reflected pulses a distance to said target, a display device for viewing said distance, and a power supply connected to said transmitter, said receiver, said processor and to said display device; and

a separable angle encoder module having an angle encoder module housing adapted to be attached to said laser based distance measuring module, said angle encoder module sensing an angle between a reference angle and an angular position of said laser module and producing an azimuth signal for said laser module, wherein said laser based distance measuring module is tiltable through up to a 360 degree vertical arc while said angle encoder module remains in a substantially constant position fastened to said laser module.

2. The system according to claim 1 wherein said laser module transmits a distance data signal to a data storage device through said angle encoder module, said angle encoder module concatenating said azimuth with said distance data to form a composite data string transmitted to said data storage device.

3. The system according to claim 2 wherein said data storage device comprises a data logger.

4. The system according to claim 3 wherein said laser based distance measuring module includes a tilt sensor measuring tilt of said module from a horizontal plane.

5. A method of taking an azimuth and distance measurement comprising the steps of:

providing a hand held laser-based distance measuring module capable of determining a distance from the laser module to a target;

electrically connecting said laser module to a separate compass module spaced from said hand held laser-based distance measuring module;

holding said compass module in a position effective to obtain an accurate azimuth reading toward said target;

tilting said laser module toward said target while holding said compass module in said effective position;

triggering said laser module to obtain said distance measurement and said azimuth measurement.

6. The method according to claim 5 further comprising fastening said compass module to said laser module to fix said modules together in a spaced horizontal relationship permitting vertical relative rotational movement between said modules through an arc of 360 degrees.

7. The method according to claim 6 further comprising the steps of:

rotating said modules to a plurality of predetermined angular positions about a vertical axis covering at least a full 360 degree horizontal rotation; and

measuring an azimuth at each of said predetermined positions;

entering each of said predetermined angular positions into said compass module to calibrate said compass module.

8. A method of taking an azimuth and distance measurement comprising the steps of:

providing a hand held laser-based distance measuring module capable of determining a distance from the laser module to a target;

electrically connecting said laser module to a separate compass module;

mounting said compass module on a vehicle;

mounting said laser module at a different location on said vehicle such that said module may be tilted about a horizontal axis;

aligning said compass module toward said target;

tilting said laser module toward said target; and

triggering said laser module to obtain said distance measurement and a compass azimuth reading to said target.

9. The method according to claim 8 further comprising the steps of:

mounting an angle encoder to said laser module which permits said laser module to be horizontally rotated about a vertical axis through said laser module mounted on said vehicle;

electrically connecting said encoder to said compass module to provide laser module azimuth information to said compass module;

aiming said laser module at said target independent of said compass module orientation;

providing relative laser module azimuth information from said encoder to said compass module when said laser module is fired at said target;

determining target azimuth from said compass azimuth and laser module azimuth information.

10. The method according to claim 9 further comprising calibrating said compass module to said vehicle by driving said vehicle in a circle and taking compass azimuth readings at a plurality of positions.

11. The method according to claim 8 further comprising

moving said vehicle to orient said compass module at a plurality of predetermined angular positions about a vertical axis covering at least a full 360 degree horizontal rotation about said axis;

and

measuring an azimuth at each of said predetermined positions;

entering each of said predetermined angular positions into said compass module to calibrate said compass module.