CN117590411A

CN117590411A - System for measuring distance by laser

Info

Publication number: CN117590411A
Application number: CN202311014580.5A
Authority: CN
Inventors: T·J·沃伊切霍夫斯基
Original assignee: Johnson Level and Tool Mfg Co Inc
Current assignee: Johnson Level and Tool Mfg Co Inc
Priority date: 2022-08-11
Filing date: 2023-08-11
Publication date: 2024-02-23

Abstract

A distance measurement system having a rotating laser generator and a laser detector. The rotary laser generator may be rotated 360 degrees along a desired plane while emitting rotary laser light. The laser detector is capable of detecting the rotating laser light, thereby allowing the laser detector to be positioned along the same plane. Each detection of the rotating laser light by the laser detector constitutes a pulse and the distance between the rotating laser generator and the laser detector can be calculated by measuring the time between pulses. In addition, the laser detector integrates distance measurement technology, so that the laser detector can measure the distance to surrounding objects. The laser detector also includes a rotation capability so that the laser detector can alternate from measuring the distance to the reference wall to measuring the distance to the ground.

Description

System for measuring distance by laser

Cross Reference to Related Applications

The present application claims the benefit of U.S. provisional patent application Ser. No. 63/397,092 filed on 8/11 of 2022, the entire disclosure and disclosure of which is incorporated herein by reference.

Technical Field

The present invention relates to a measuring instrument system for measuring a distance between an instrument and an ambient environment.

Background

In general, measuring instruments are used in the construction industry. In construction, small measurement errors can cause large problems. Therefore, a measuring instrument providing a precise distance is required. Furthermore, the desire for building site efficiency requires that the measurement system provide measurements quickly and with as few instrumentation as possible.

One common measuring instrument is a rotary laser generator. A rotary laser generator is typically used to find and mark the level, commonly referred to as a rotary laser level. A typical rotary laser generator emits laser light that rotates rapidly through 360 degrees. This laser rotation produces horizontal light on surrounding objects at a given laser plane. Surrounding objects may include, but are not limited to, walls, beams, and floors. Typically, a rotating laser generator has a self-leveling feature or some other means known in the art for fixing the laser on a horizontal or vertical plane. This feature ensures that the laser rotates about the horizontal plane.

The rotary laser generator may also be used in series with other measuring instruments. For example, a location of interest may lack a reference object on which horizontal rays may be displayed. A measuring stick or other instrument may be used to provide a physical surface that makes horizontal light visible. The measuring stick may be a thin stick that is easy to move and may be positioned perpendicular to the ground in a desired position.

Furthermore, instead of using visible light displayed on a physical object to mark a plane, an instrument having a sensor capable of detecting laser light may be used. An instrument capable of sensing laser light may be referred to as a laser detector. Similar to the measuring rod, the laser detector may be positioned at a location of interest. The laser detector may then sense when the laser detector is aligned with the plane generated by the rotating laser generator. If the laser detector deviates from the desired plane, the laser detector can also provide a measurement to quantify this deviation.

Once the rotating laser generator and laser detector are aligned along the desired plane, multiple distances may need to be measured. First, it may be necessary to determine the distance along the desired plane from the rotating laser generator to the laser detector. Furthermore, it may be necessary to know the distance from the laser detector to surrounding objects, such as a reference wall. Furthermore, when the desired plane is horizontal, the heights of the rotating laser generator and the laser detector from the ground are equal. However, if the elevation of the field is not uniform, it may also be necessary to know the distance of the laser detector from the ground. When using many measuring instruments on the market, these measurements are often not readily available or determinable.

One known method of measuring these distances is to use a laser ranging (LDM) instrument. LDM instruments use well known time-of-flight methods to measure the distance from the instrument to a reference object. Typically, LDM instruments emit laser pulses towards a reference object. The laser pulse impinges on the reference object and is reflected back to the LDM instrument. The sensor on the LDM instrument receives the reflected laser pulses. Because the speed of the laser pulse is the speed of light (which is a constant), the distance between the LDM instrument and the reference object can be calculated by measuring the time required for the laser pulse to propagate to the reference object and back to the LDM instrument. Typically, the equation for LDM instruments is that the distance is equal to the speed of light times the travel time divided by 2.

However, the use of LDM instruments has its drawbacks, particularly when used in conjunction with rotating laser generators and detectors. LDM instruments are typically stand-alone handheld devices that require the purchase, maintenance, and use of additional instruments. The use of additional instrumentation may not be cost effective or most efficient. In addition, handheld devices often include some inherent human error because a person cannot hold the handheld device completely stationary or in an accurate location.

In addition, other measuring instruments on the market may require at least two users, or may require a single user to move multiple locations. Some instruments may need to be adjusted or stabilized from multiple locations simultaneously, which may require multiple users. While a user may use other instruments, the user may be forced to constantly move the position to obtain the necessary measurements.

Disclosure of Invention

The disclosed invention solves the above-mentioned problems by providing a system for measuring distance using a laser. The system includes a method of measuring a distance along a desired plane from a rotating laser generator to a laser detector. In addition, the system includes a method of measuring the distance from the laser detector to surrounding reference objects, such as reference walls and ground.

First, the system may be positioned along a desired plane. The rotary laser generator can be used as a rotary laser level for its normal function, finding the desired plane by rotating rapidly 360 degrees along the plane. The laser detector may then be used to detect the laser light from the rotating laser generator, allowing the laser detector to be positioned at a location of interest along a desired plane.

Once the rotating laser generator and laser detector are positioned along the desired plane, the system may measure the distance along that plane from the rotating laser generator to the laser detector. Similar to the leveling operation of the rotary laser generator, the rotary laser generator emits laser light and rapidly rotates the laser light 360 degrees along a plane. The rotational speed of the rotating laser generator may be known and may be expressed in Revolutions Per Minute (RPM). The known RPM of the rotating laser generator may then be transferred to the laser detector by some means known in the art.

As the rotating laser generator rotates and the laser detector is aligned along the plane, the rotating laser from the rotating laser generator will be aligned with the laser detector once per revolution. When the rotating laser light is aligned with the laser light detector, the laser light detector will sense the rotating laser light. Each time the laser detector detects a rotating laser light may be referred to as a pulse. Each pulse has a corresponding time, which is measured by the laser detector.

The time between pulses can be used to calculate the distance between the rotating laser generator and the laser detector. The time between pulses corresponds to the time the spinning laser generator rotates once plus the time the spinning laser propagates from the spinning laser generator to the laser detector. The known rotation rate can be used to calculate the time of one rotation and then allow the propagation time of the rotating laser to be calculated. The rotating laser light propagates from the rotating laser generator to the laser detector at a constant speed of light. Thus, the rotational laser travel time and speed of light can be used to calculate the distance between the rotational laser generator and the laser detector. The rotational laser travel time times the speed of light equals the distance.

In addition to measuring the distance between the rotating laser generator and the laser detector, it may also be necessary to determine the distance of the laser detector to a surrounding reference object or surface. For example, it may be beneficial to find the distance from the laser detector to the reference wall. In addition, it may be desirable to measure the distance of the laser detector from the ground.

The laser detector may be combined with known measuring instruments to obtain these measurements. Laser ranging (LDM) is one type of example of such a measuring instrument. By incorporating the LDM instrument into the laser detector, the laser detector is able to measure the distance to the reference object. Using LDM, a laser detector may emit laser pulses towards a reference object, such as a wall. The laser pulse will strike the reference object and reflect back to the laser detector. The laser detector may comprise an LDM sensor capable of detecting reflected laser pulses. Because the speed of light is constant, the time it takes for the laser pulse to strike the reference object and reflect back to the laser detector can be used to measure the distance. Typically, when LDM techniques are used, the distance traveled by the laser pulses is equal to the travel time times the speed of light. Then, because the distance traveled by the laser pulse includes both outgoing and incoming strokes, the distance is divided by 2.

Furthermore, the laser detector may comprise the capability to rotate, for example by at least 90 degrees. Such rotation may allow the laser detector to alternate, for example, between measuring the distance to the reference wall and measuring the distance to the ground. Typically, in LDM embodiments, the side of the laser detector that emits and receives the laser pulses will be rotated from the aiming reference wall to the aiming ground. Such a rotation function may provide the ability for the laser detector to measure a desired distance to various different reference objects or surfaces.

One possible benefit of such a distance measurement system is that all measurements can be displayed on the laser detector. That is, the laser detector may include a local display that provides all available measurements as described above, as well as other system parameters. This arrangement may allow a single user to obtain multiple measurements using only the rotating laser generator and laser detector without having to move the position. No additional instrument operator or additional instruments may be required.

These and other aspects and objects of the present invention will be better understood and appreciated when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following description, while indicating preferred embodiments of the present invention, is given by way of illustration and not limitation. Many changes and modifications may be made within the scope of the present invention without departing from the spirit thereof, and the invention includes all such modifications.

Drawings

Representative exemplary embodiments of the present invention are illustrated in the accompanying drawings, wherein like reference numerals refer to like parts throughout, and wherein:

fig. 1 shows a side view of a rotary laser generator with a laser detector aimed at the ground.

Fig. 2 shows a top view of the rotating laser generator and laser detector as in fig. 1, with the laser detector rotated 90 degrees and aimed at a surface such as a reference wall.

Detailed Description

The invention and its various features and advantageous details are explained more fully with reference to the non-limiting embodiments that are described in detail in the following description.

Fig. 1 and 2 depict a distance measurement system 100 having a rotating laser generator 110 and a laser detector 130. Within the system, the laser detector 130 is capable of measuring a plurality of distances, such as the distance between the rotating laser generator 110 and the laser detector 130, the distance between the laser detector 130 and the reference object or surface 150, the distance between the laser detector 130 and the ground 152, and the distance between the laser detector and the reference wall 154. These distances will be referred to herein as laser detector distance 210, detector reference distance 220, detector ground distance 222, and detector wall distance 224, respectively.

In fig. 1 and 2, the rotating laser generator 110 and the laser detector 130 are aligned on the same plane. These embodiments show alignment along a horizontal plane. Alignment systems along the horizontal plane may be common because the rotating laser generator 110 may also be used as a rotating laser level, which may be used to find the level plane. However, other embodiments may align the rotating laser generator 110 and the laser detector 130 along different planes, such as a vertical plane.

Typically, when the system is set up, the rotating laser generator 110 is positioned with the laser light emitted along the desired plane. Such positioning may be accomplished using self-leveling functions or other known methods in the art of establishing a desired plane. The rotary laser generator 110 emits rotary laser light 120 (which is rotary). The rotating laser 120 may be rotated 360 degrees.

The laser detector 130 may then be placed in the desired location. The laser detector 130 includes a sensor that can detect laser light directed toward the laser detector 130. Thus, when the rotating laser 120 is aligned with the laser detector 130, the laser detector 130 may detect the rotating laser 120. The height of the laser detector 130 may be adjusted so that the sensor is aligned in the same plane as the rotating laser 120. In one embodiment, the sensor detecting the rotating laser 120 confirms that the rotating laser 120 and the laser detector 130 are aligned on the same plane. In another embodiment, the laser detector 130 is capable of detecting the rotating laser light 120 when the rotating laser light and the laser detector 130 are not perfectly aligned on the same plane. The laser detector 130 may provide a displacement measurement that specifies the distance of the laser detector 130 from the plane of the rotating laser 120.

The rotary laser generator 110 and the laser detector 130 may be supported in a variety of different ways. The support may minimize unwanted movement. Fig. 1 depicts a rotating laser generator supported by a tripod 160. The laser detector 130 may also be supported by a similar support. The support may allow for the ability to adjust the height of the instrument. Furthermore, the support may be permanently attached to the instrument or may be detachable. In an embodiment, the support for one or both instruments may be a straight bar or rod that is held vertically by the user. In another embodiment, one or both instruments may be located on the ground 152, with no support at all.

Measuring distance between rotating laser generator and laser detector

Fig. 1 and 2 depict an arrangement in which the laser detector distance 210 may be measured. The rotary laser generator 110 may rotate the rotary laser 120 360 degrees. During each rotation, when the rotating laser 120 is aligned with the laser detector 130, the laser detector 130 will detect the rotating laser 120. Such detection may be referred to as pulsing. Thus, each revolution of the rotating laser 120 produces a pulse having a corresponding time.

The laser detector 130 will use the time difference between pulses to calculate the laser detector distance 210. The time between each pulse and the known rotational speed of the spinning laser generator 110 may be used to derive the time it takes for the spinning laser 120 to travel from the spinning laser generator 110 to the laser detector 130. The time that the rotating laser 120 travels the laser detector distance 210 may be referred to as the laser time of flight. Once the laser time of flight is known, the speed of light can be used to calculate the laser detector distance 210.

There are two time variations in the time between each pulse: the time of one revolution of the spinning laser generator 110 and the laser flight time. The time per revolution plus the laser flight time is equal to the time between pulses. Since the time per revolution and the time between pulses can be measured and calculated, the laser time of flight can also be calculated.

Because the rotation rate of the rotating laser generator 110 may be known, the time per revolution may be calculated. The known rotational speed may be communicated to the laser detector 130. Different embodiments may communicate the rotational speed in a variety of ways, such as by manual input, hardwired communication, cellular communication, bluetooth, a signal sent via WiFi, or some other way known in the art. The rotational speed may be measured in Revolutions Per Minute (RPM) and may be converted to time per revolution as shown in the following equation:

wherein:

different embodiments of the rotary laser generator 110 may rotate at different speeds. Examples of possible rotational speeds include, but are not limited to, 300RPM, 600RPM, and 1200RPM. Further, in some embodiments, the rotating laser generator 110 can rotate at different speeds, and the rotational speed can be an input variable.

Once the time per revolution is calculated, the laser time of flight can be calculated. The laser flight time is equal to the time between pulses minus the time per revolution. The laser detector 130 measures the pulse and the corresponding pulse time. Thus, the laser detector 130 may generate the time between pulses. Since both variables are known, the laser time of flight can be calculated by the following equation:

t _ToF ＝Δt _pulse -t _rev wherein:

t _TOF laser time of flight (seconds);

Δt _pulse time between pulses (seconds).

After calculating the laser time of flight, the laser detector distance 210 may be calculated because the rotating laser 120 travels at the speed of light (which is a constant). The speed of light is equal to 299792458 meters/second or 983571056 feet/second. The speed of light multiplied by the laser time of flight equals the laser detector distance 210 as shown in the following equation:

x _L-D ＝t _ToF * c, wherein:

x _L-D ＝laser-detector distance(ft)；

in addition, the time between pulses may be used to generate a pulse frequency that is related to the laser detector distance 210. A cycle may be considered to be a single rotation of the rotating laser generator 110 plus the rotating laser 120 traveling to the laser detector 130. Thus, the time of the cycle is the time between pulses. The inverse of the cycle time is equal to the pulse frequency. This is expressed by the following equation:

f＝1/Δt _pulse wherein:

f＝frequency(Hz)。

the laser detector 130 may use the frequency to determine a corresponding laser detector distance 210.

Examples:

here is an example of calculating the corresponding frequency of this embodiment. Suppose the rotating laser generator 110 rotates at 600RPM and the laser detector distance 210 is 500 feet. The pulse frequency recorded by the laser detector can be calculated by:

Δt _pulse ＝t _rev +t _ToF ＝0.1(sec)+5.083*10- ⁷ (sec)＝0.1000005083(sec)，

if the laser detector is to measure the frequency, a reverse calculation can be performed to calculate the distance of the laser detector.

Measuring distance between laser detector and reference object

In addition to the laser detector distance 210, the distance measurement system may also provide a distance from the laser detector 130 to the reference object 150. The reference object 150 may include a ground 152, a reference wall 152, or any other surrounding object. The laser detector reference distance 220 includes a detector ground distance 222 and a detector wall distance 224.

These distances may be measured by incorporating known measuring instruments into the laser detector 130. The laser detector 130 itself has this capability rather than using a separate instrument to measure these distances.

In one embodiment, laser detector 130 may incorporate laser ranging (LDM). LDM is a measurement technique known in the art. By incorporating LDM into the laser detector 130, the laser detector 130 may be aimed at a reference object 150, such as a ground 152 or a reference wall 154. The laser detector 130 may emit laser pulses 140 toward a reference object 150. The laser pulse 140 may hit the reference object 150 and reflect back to the laser detector 130. The laser detector 130 may incorporate a sensor designed to receive or detect the reflected laser pulses 140. The laser detector 130 may measure the time between the emission of the laser pulse 140 and the detection of the reflected laser pulse 140.

The laser detector 130 incorporating LDM technology can use the laser pulse 140 travel time to calculate the detector reference distance 220. The laser pulse 140 propagates at a constant speed of light. Thus, the time that the laser pulse 140 propagates to the reference object 150 and returns to the laser detector 130 can be used to calculate the detector reference distance 220. Typically, the detector reference distance 220 is equal to:

wherein:

x _D-R ＝dectector-reference distance(ft)；

t _LP ＝laser pulse travel time(sec)。

as shown in the equation, the laser pulse 140 travel time is related to twice the detector reference distance 220 because the laser pulse 140 travels twice this distance to the reference object 150 and back to the laser detector 130.

The laser detector 130 also incorporates a rotation function, which allows the laser detector 130 to measure distances in different directions. In general, distance measurement techniques require that the instrument be aimed in a direction of the desired distance and toward a target or surface oriented to enable the laser beam to be reflected back to the detector. Thus, if the laser detector 130 incorporates distance measurement techniques, the laser detector 130 may need to be aimed in a certain direction. In embodiments where the laser detector 130 includes LDM technology, one side of the laser detector 130 may emit and subsequently detect the laser pulses 140. This side may be referred to as the measurement side. The measurement side may need to be aimed at a desired distance or, in other words, at the reference object 150. Thus, the rotation function allows the laser detector 130 to change the direction in which it is aimed.

Comparing fig. 1 and 2 demonstrates this rotation function. Fig. 1 depicts the measurement side of the laser detector aimed down along a vertical plane at the ground 152. In this arrangement, the laser detector 130 may measure the detector ground distance 222. In LDM embodiments, laser pulses 140 will be emitted vertically downward toward ground 152 and reflected upward toward laser detector 130. Such an arrangement may be beneficial if the distance measurement system 100 is used in locations having uneven heights. While the rotary laser generator 110 and laser detector 130 may be located in a horizontal plane, as shown in fig. 1, the height of the instrument from the ground 152 at their respective locations may not be equal.

The change from fig. 1 to fig. 2 is that the laser detector 130 in fig. 2 is rotated 90 degrees relative to the position shown in fig. 1. In fig. 2, the measurement side of the laser detector 130 faces a surface such as a reference wall and the detector wall distance 224 is measured. In LDM embodiments, the laser pulses 140 will be emitted horizontally toward the reference wall 154 and reflected back toward the laser detector 130. This arrangement facilitates determining the distance of the laser detector 130 from surrounding items in the area.

The rotation function may be achieved by attaching the laser detector 130 to a rotating or pivoting connection. Different embodiments may include swivel hinges, swivel joints, movable pins, or some other swivel connection known in the art. The support of the laser detector 130 may be offset from the laser detector 130 so that the measurement side may be aimed downward without interference. Furthermore, an embodiment may include locks or stabilizers for rotational connection at different rotational intervals (e.g., 90 degrees or 45 degrees). The lock or stabilizer may prevent unwanted movement of the laser detector 130 when measuring. Another embodiment may allow rotation of more or less than 90 degrees. An embodiment may allow 360 degrees of rotation. The laser detector 130 may include a level and plumb gauge for horizontally and vertically positioning the laser detector, respectively.

It is also contemplated that the laser detector 130 may incorporate two separate LDM distance measurement systems that emit and receive laser beams that are perpendicular to each other. In such an embodiment, the detector wall distance 224 and the detector ground distance 222 may be measured simultaneously without the need to rotate the laser detector 130 on its support structure.

Display of measurements

A possible benefit of the distance measurement system 100 is that the measured distance may be displayed on a local display of the laser detector 130, the laser detector 130 comprising means to present different distances that may be measured in the system. By including a display at the laser detector 130, the user can effectively obtain all desired measurements without having to move between different instruments or positions. The local display may present the laser detector distance 210, the detector ground distance 222, the detector wall distance 224, or any other parameter that the laser detector 130 may obtain, such as the rotation rate of the rotating laser generator 110.

The laser detector 130 display may be a digital screen that provides readings of distance and other parameters. The screen may be a Liquid Crystal Display (LCD). In an embodiment, the display may have the ability to display all measured distances simultaneously, or may be switched between different parameter outputs or options. The screen may also have touch screen functionality or may be controlled by local buttons on the laser detector 130. In addition, the display can receive inputs that control system operation. For example, a user can select a desired rotating laser generator RPM using a display. The various measured parameters or distances may also be displayed on the screen of the mobile device using a software application on the mobile device, where the laser detector 130 and the mobile device communicate via bluetooth, wi-Fi, cellular signals, or any other known means of communication.

While the best mode contemplated by the inventors of carrying out the present invention has been disclosed above, practice of the present invention is not limited thereto. It will be apparent that various additions, modifications and rearrangements of the features of the invention may be made without departing from the spirit and scope of the basic inventive concepts.

Furthermore, the individual components need not be formed in the disclosed shapes or assembled in the disclosed configuration, but rather may be provided in virtually any shape and assembled in virtually any configuration. Furthermore, all disclosed features of each disclosed embodiment may be combined with or substituted for the disclosed features of each other disclosed embodiment unless the features are mutually exclusive.

Claims

1. A distance measurement system, comprising:

a rotating laser generator emitting laser light, wherein the laser light rotates in a plane at a known RPM; and

a laser detector on the plane, wherein the laser detector is capable of sensing the laser light when the laser light is aligned with the laser detector along the plane, wherein the sensing of the laser light during laser rotation is designated as pulses, and wherein at least two pulses are generated during laser rotation having a time corresponding to each pulse; wherein the distance between the rotating laser generator and the laser detector on the plane is calculated using the time corresponding to each pulse, the known RPM and the speed of light.

2. The distance measurement system of claim 1, wherein a distance between the rotating laser generator and the laser detector is displayed on the laser detector.

3. The distance measurement system of claim 1, wherein the distance between the rotating laser generator and the laser detector is displayed on a mobile device via a wireless communication protocol and a software application on the mobile device.

4. The distance measurement system of claim 1, wherein the laser detector comprises a laser distance measurement device, wherein the laser distance measurement device is configured to measure a distance between the laser detector and a surface other than a plane in which the laser rotates.

5. The distance measurement system of claim 4 wherein the laser distance measurement device measures the distance between the laser detector and the surface using laser light emitted from the laser detector and reflected from the surface toward the laser detector.

6. The distance measurement system according to claim 5, wherein the orientation of the laser detector is changeable to measure the distance between the laser detector and the plurality of surfaces.

7. The distance measurement system of claim 6, wherein the laser detector is orientable to measure a horizontal distance between the laser detector and a vertical surface, and is further orientable to measure a vertical distance between the laser detector and the horizontal surface.

8. The distance measurement system of claim 5 wherein the laser distance measurement device measures a first distance between the laser detector and the first surface using a first laser light emitted from the laser detector and reflected from the surface toward the laser detector and measures a second distance between the laser detector and the second surface using a second laser light emitted from the laser detector and reflected from the surface toward the laser detector.

9. A method for measuring a distance between a rotating laser generator and a laser detector on a plane, comprising:

emitting laser light from a rotating laser generator;

rotating the laser along the plane at a known RPM;

generating pulses when the laser is aligned with the laser detector along the plane, wherein at least two pulses are generated having a time corresponding to each pulse; and

the distance between the rotating laser generator and the laser detector on the plane is calculated using the time corresponding to each pulse, the known RPM and the speed of light.

10. The method of claim 9, comprising displaying a distance between the rotating laser generator and laser detector on the laser detector.

11. The method of claim 9, comprising measuring a distance between the laser detector and a surface other than a plane in which the laser rotates.

12. The method of claim 11, wherein measuring the distance between the laser detector and the surface is performed by measuring the distance between the laser detector and the surface using laser light emitted from the laser detector and reflected from the surface toward the laser detector.

13. The method of claim 12, comprising changing an orientation of the laser detector to measure a distance between the laser detector and the plurality of surfaces.

14. The method of claim 13, comprising orienting the laser detector to measure a horizontal distance between the laser detector and a vertical surface, and further orienting the laser detector to measure a vertical distance between the laser detector and the horizontal surface.

15. The method of claim 14, comprising measuring a first distance between the laser detector and the first surface using a first laser light emitted from the laser detector and reflected from the surface toward the laser detector, and measuring a second distance between the laser detector and the second surface using a second laser light emitted from the laser detector and reflected from the surface toward the laser detector.

16. A laser detector, comprising:

a first sensor having the ability to detect a laser signal emitted from an external source to measure a first distance;

a measurement assembly having the capability of measuring a distance to a reference object;

wherein the measurement assembly comprises a laser generator capable of emitting outgoing laser pulses towards the reference surface and a second sensor capable of detecting laser pulses reflected from the reference surface for measuring a second distance between the laser detectors, wherein the second distance is the distance between the laser detectors and the reference surface.

17. The laser detector of claim 16, wherein the first distance is measured using a rotating laser generator that emits laser light, wherein the laser light rotates in a plane at a known RPM, wherein the laser detector is on the plane, wherein the laser light is capable of being sensed by the laser detector when the laser light is aligned with the laser detector along the plane, wherein the sensing of the laser light during the laser rotation is designated as a pulse, and wherein at least two pulses are generated during the laser rotation having a time corresponding to each pulse, wherein the first distance between the rotating laser generator and the laser detector is calculated using the time corresponding to each pulse, the known RPM, and the speed of light.

18. The laser detector of claim 17, wherein an orientation of the laser detector can be changed to measure a distance between the laser detector and the plurality of surfaces.

19. The distance measurement system according to claim 18, wherein the laser detector is orientable to measure a horizontal distance between the laser detector and a vertical surface, and is further orientable to measure a vertical distance between the laser detector and the horizontal surface.

20. The laser detector of claim 16, wherein a distance between the rotating laser generator and the laser detector is displayed on the laser detector along with the second distance.