WO2001016560A2

WO2001016560A2 - Method and apparatus for snow depth mapping

Info

Publication number: WO2001016560A2
Application number: PCT/CA2000/001411
Authority: WO
Inventors: Manon Fortin
Original assignee: Bombardier Inc.
Priority date: 1999-11-30
Filing date: 2000-11-29
Publication date: 2001-03-08
Also published as: CA2394243A1; WO2001016560A3; AU1847201A

Abstract

The apparatus for measuring snow depth at a predetermined location features a mobile vehicle and a global positioning system capable of determining a latitude, a longitude, and an elevation of the mobile vehicle at the predetermined location and of generating a positional data signal representative thereof. A ground penetrating radar is capable of measuring the snow depth at the predetermined location and of generating a snow depth data signal representative thereof. A computer in communication with the global positioning system and the ground penetrating radar, is capable of linking the positional data signal and the snow depth data signal for the predetermined location.

Description

METHOD AND APPARATUS FOR SNOW DEPTH MAPPING

The present application claims priority to U.S. Provisional Application of Fortin, Ser. No. 60/167,914, filed November 30, 1999, the entirety of which is hereby incorporated into the present application by reference.

Field of the Invention

The present invention relates to a method and apparatus for measuring, recording, and mapping snow depth at particular positional coordinates using a ground penetrating radar (GPR) system in cooperation with a global positioning satellite system (GPS).

Background of the Invention

For skiing resorts, measuring the depth of snow at various locations on the ski slopes is particularly important. At the end of each skiing day, the skiing resorts send a number of ski slope groomers onto the mountain trails to smooth the trails in preparation for the next day's skiing.

Often, the groomers are required to move or distnbute snow from a location where it has accumulated to a location that has become bare from use. To do this effectively, groomers must be able to measure snow accumulation or depth at particular positional coordinates. Traditionally, snow depth has been measured using only Global Positioning System (GPS) assemblies, which generally include a worldwide radio-navigation system formed from a constellation of satellites and their ground stations.

Conventional GPS assemblies can determine particular positional coordinates by "triangulation'^" from satellites, m which a GPS receiver measures the distance to 3 or more satellites (usually 4) using the travel time of radio signals sent from each satellite to arrive at the GPS receiver. The signal sent from each satellite provides information about the satellite location. From this information, the distance from the satellite to the GPS receiver can be determined. Typically, GPS assemblies need very precise timing devices to measure travel time for the radio signals between the satellite and the GPS module. To ensure accuracy of the device, corrections must be applied for any delays the signal may experience as it travels through the atmosphere.

One conventional type of GPS assembly commonly known in the art is the Differential Global Positioning System (DGPS), which can be used to obtain highly accurate positional coordinates. As shown in Fig. 1, the DGPS assembly 10 involves the co-operation of two receivers, a base unit 12 and a rover 14, for communicating with a constellation of 24 satellites, generally indicated at 16, and their ground stations. These satellites, or "man-made stars", are used as reference points to calculate positions that can be accurate to a matter of meters. Typical stationary base units 12 include a satellite receiver antenna 18 in communication with a GPS base receiver and processor 20. Base units 12 may further include a radio modem 22 in communication with a transmitter unit 24. In addition, in order to compensate for timing errors, each base unit 12 is typically positioned at a fixed location having known longitude, latitude and elevation coordinates so as to tie all the satellite measurements into a solid local reference that has been very accurately surveyed. In snow depth mapping instances, the base unit 12 typically is positioned at an alpine ski resort located on a mountain or at the base thereof.

Rover units 14 are used to take position measurements. The rover units 14 include a satellite receiver antenna 26 in communication with a GPS rover receiver and processor 28. They may also include a radio modem receiver antenna 30 in communication with a signal receiver unit 32 and a data input/output (I/O) device 34, from which data may be periodically transferred to another device such as an on-board computer or to another location such as an administrative office (not shown), via, e.g., electronic transfer, RF signal transfer, or manual transfer of a data diskette.

During normal operation of the conventional DGPS assembly 10, satellite signals are continuously received from the available satellites 16 by the receiver antennas 18 and 26. The longitude, latitude, and elevation of the base unit 12 are known and are compared with the signals received from the satellites 16 by the rover 14. The difference between the received and pre-recorded known data is used to correct the information received by the rover unit 14 and can typically be supplied to the rover 14 either post-process (after position measurement taking) or in real-time (instantaneously) to eliminate almost all error.

U.S. Patent No. 5,761,095, which issued to Warren on June 2, 1998, describes the primary conventional way in which snow depth has been measured. The entire disclosure of U.S. Patent 5,761,095 is incorporated herein by reference. The conventional DGPS assembly 10, similar to that shown in U.S. Patent No. 5,761,095, can measure snow depth by communicating with a constellation of satellites 16. As illustrated in Figs. 1-3, which are labeled "PRIOR ART," the DGPS assembly 10 can be located both within a lawn mowing tractor 36 (or other ground vehicle) to collect ground surface data and within a snow groomer 38 to collect snow surface data.

Particularly, when there is no snow on the ground, the lawn mowing tractor 36 equipped with the DGPS 10 can be maneuvered over the ground surface 40 (i.e., while mowing the grass) to collect ground surface data via the DGPS 10 communicating with the satellites 16 as described above. Ground surface data refers to a series of ground positions measured in relation to a fixed reference point from which a three-dimensional map of the ground surface terrain may be extrapolated.

After the ground surface data has been collected and snow has fallen onto the ground, the snow groomer 38, also equipped with the DGPS 10, can be maneuvered over the snow surface 42 (i.e. while grooming ski slopes) to collect snow surface data via the DGPS 10 communicating with the satellites 16 as described above. Snow surface data is a collection of snow surface data points that, when assembled and compared to a fixed reference point, permits generation of a three-dimensional map of the snow surface terrain.

To generate a three-dimensional map of the depth of the snow, it is necessary to compare the snow surface map with the ground surface map. Specifically, as illustrated in Fig. 4, the ground surface map is subtracted from the snow surface map to generate a Ah (representing the snow depth) at any given location on the mountain.

While effective in establishing a general map for the snow depth at various specific locations on a ski slope, this technique has proven to be quite cumbersome because the operator of the snow groomer 38 does not have immediate access to the depth of the snow at any particular location on the mountain. Only after the snow surface data is compared with the ground surface data can a depth map be created for use in snow grooming operations.

Moreover, by using DGPS assemblies 10 for measuring, recording, and mapping of snow depth, desired graphical representations of the ground surface and/or the snow surface can be achieved, but that extra procedures are required. Because DGPS assemblies 10 cannot measure both ground and snow surface position data simultaneously, the DGPS assembly 10 has to be maneuvered over the ground and snow surfaces at separate times to be effective. In addition, if the ground surface is changed, for example by adding new ski slopes, the DGPS assembly 10 must be used to generate ground surface data in those areas. These added procedures for measuring, recording, and mapping snow depth can take massive amounts of time and manpower, thus unnecessarily increasing the cost of snow depth measuring, recording, and mapping.

Consequently, there exists a need in the art for an apparatus for measuring, recording, and mapping the snow depth at a particular positional coordinate, whereby an accurate measurement of the depth of the snow at that particular positional coordinate is provided simultaneously.

Summary of the Invention An aspect of the present invention is to provide an apparatus for measuring snow depth at a predetermined location. The apparatus features a mobile vehicle and a global positioning system capable of determining a latitude, a longitude, and an elevation of the mobile vehicle at the predetermined location and of generating a positional data signal representative thereof. A ground penetrating radar is capable of measuring the snow depth at the predetermined location and of generating a snow depth data signal representative thereof. A computer in communication with the global positioning system and the ground penetrating radar, is capable of linking the positional data signal and the snow depth data signal for the predetermined location.

Other aspects, features and advantages of the present invention will become apparent from the following detailed description, the accompanying drawings, and the appended claims. Brief Description of the Drawings

Fig. 1 is a functional block diagram of a conventional GPS assembly for measuring particular positional coordinates; Fig. 2 is a side elevational view showing a tractor or mower for collecting ground surface data according to the prior art method;

Fig. 3 is side elevational view showing a snow groomer for collecting snow surface data according to the prior art method;

Fig. 4 is a cross-section illustrating how the depth of snow has been determined by the prior art technique;

Fig. 5 is a functional block diagram of the apparatus of the present invention;

Fig. 6 is a side elevational view showing the simultaneous collection of positional coordinates via the GPS assembly and snow depth data via the GPR assembly;

Fig. 7 is a graphic depiction of the positional coordinate data and the ground and snow surface data collected using the apparatus illustrated in Figs. 5 and 6; and

Fig. 8 is a block diagram setting forth the steps of the method for measuring snow depth according to the teachings of the present invention.

Detailed Description of the Preferred Embodiments Figs. 5-8 show an apparatus for measuring, recording, and mapping the depth of snow according to the present invention. The apparatus, generally indicated at 50, includes a Global Positioning System (GPS), generally indicated at 52. and a Ground Penetrating Radar (GPR) system, generally indicated at 54, both of which are provided on a roving vehicle 56 (i.e., a snow grooming vehicle) having a working implement 70 (otherwise known as a tiller). As the snow grooming vehicle 56 moves over a selected area 58, the GPS assembly 52 collects position data and the GPR assembly 54 collects snow depth data for the selected area 58 (as described in greater detail below). Both sets of data are stored within an on-board computer 60. The on-board computer 60 links the position data with the snow depth data to create a database that calculates the snow depth for the selected area 58. The database is stored in a data module 62 and can be manipulated by computer software to create a snow depth map 64 (Fig. 7), which is viewable on a display screen (not shown) of the on-board computer 60 in either a flat, two-dimensional view or a three-dimensional view. The map 64 will allow the snow grooming vehicle 56 to use a work implement 70 (e.g., a tiller) efficiently to groom the snow into desired shape contours and/or snow depth distributions.

Snow grooming vehicle 56 is also provided with a plow 65 at a front end for pushing large quantities of snow to a location 58 where the snow depth has fallen below a minimally acceptable depth or where an ice patch has been created or revealed due to use by skiers. In such an instance, plow 65 can be used to move snow from a positional location where there is an excess of snow to the positional location where additional snow is required.

Fig. 5 illustrates a GPS assembly 52 according to the present invention. Those elements that are similar to the elements shown in the prior art GPS assembly 10 (Figs. 1-3) are not discussed in detail and are indicated with the same reference numerals. Since the GPS assembly 52 uses some elements similar in both construction and operation as GPS assembly 10, the above described explanation of these elements in GPS assembly 10 will suffice to give an understanding of both structure and operation of the same elements of GPS assembly 52. Preferably, the GPS assembly 52 used to determine the groomer' s position is manufactured by Ashtech Precision Products (Magellan Corporation, Santa Clara, California, USA) and sold under the name GPS series GBX Pro. While this particular model is preferred, it should be noted that any other model of GPS may be substituted therefor without deviating from the scope and spirit of the present invention.

Once the particular positional coordinates, such as latitude, longitude and elevation have been obtained for locations covered by the snow groomer 56, the GPS assembly 52 sends the position data in real time via its RS-232 serial port to the on-board computer 60. To correct for errors in the positional coordinates data relayed by the GPS assembly 52, any suitable method known in the art (including the technique described above) may be employed.

With continued reference to Figs. 5 and 6, the GPR assembly 54 is adapted to measure snow depth. The GPR assembly 54 includes a transducer or antenna 66, which is set-up (i.e., "tuned") for the snow dielectric particularity. This means that the GPR transmission frequency is adjusted to sense the subsurface interface between the snow and the ground by distinguishing between their differing dielectric properties.

It may be preferable for the transducer 66 to be adaptable such that finer frequency adjustments can be made. Adjustments may be required because of the expected depth of the snow. Also, frequencies may differ depending on the snow conditions in which the measurements are to be made. Turning the GPR frequency for expected conditions and depths is well known in the art and therefore will not be further described herein.

In the preferred embodiment, the GPR assembly 54 is adapted to scan in front of the snow grooming vehicle 56 as it traverses the selected area 58. To this end, the transducer 66 is positioned beneath the front underside of the snow grooming vehicle 56 (generally under the cab). Preferably, transducer 66 provides scanned coverage of the width of the snow grooming vehicle 56 and the effective working width of the work implement 70. An electronic module 68, such as a digital control unit, communicates with the transducer 66 and has dedicated software (not shown), which provides a proper algorithm to isolate the snow depth from all of the noise received. Positioned within the electronic module 68 is a digital-to-analog converter (not shown), which communicates the measured snow depth as a voltage signal to the on-board computer 60 for further processing and display. Alternatively, the voltage signal communicated from the GPR assembly 54 could also be transmitted as digital data via a communication port (not shown). Preferably, the dedicated software is specifically written for the GPR assembly 54 to sense snow depth. Such software is commercially available from SnowScan, a division of Sensors and Software, Inc. of Mississauga, Ontario. However, any software providing an algorithm capable of isolating snow depth from all the noise received by the transducer and electronic module will be sufficient and may be supplied by any manufacturer and/or supplier of GPR equipment.

The preferred GPR assembly 54 is commercially available from SnowScan, a division of Sensors and Software, Inc. of Mississauga, Ontario.

Referring to Figs. 4 and 5, the on-board computer 60 is basically a micro-controller with input and output drivers for controlling the GPS assembly 52 and the GPR assembly 54. The on-board computer 60 is calibrated and programmed to receive and interpret both the voltage signal communicated from the electronic module 68 as a snow depth measurement and the position data sent from the data input/output (I/O) device 34 of the GPS assembly 52. The computer 60 receives the position data through a serial communication port driver (not shown) and links it with the snow depth data received from the electronic module 68. Once linked, another serial communication port driver (not shown) transmits the database containing snow depth for the selected area 58 to the storage module 62.

The computer 60 includes dedicated software, stored on an EEPROM or a SRAM memory, for manipulating the different I/O to provide the desired result in the form of graphical representations of the ground and snow surfaces 44, 46. More specifically, since the created database is stored in the data module 62, the dedicated software of computer 60 can manipulate the database to generate the snow depth map 64. The database can be stored in any electronic memory type that allows dedicated software to manipulate the database in such a way as to generate a snow depth map.

As best shown in Fig. 7, the snow depth map 64 graphically represents the ground and snow surfaces 44, 46, wherein the area "d" between the ground and snow surface maps 44, 46 represents the volume or depth of snow. When the ground and snow surface maps 44, 46 are generated, each data point (in x-y-z coordinates) is representative of a measured set of longitude, latitude and elevation data for a particular point on the ground and snow surface 44, 46, respectively.

The map 64 can be viewed in flat, two-dimensional views or in three-dimensional views on the display screen on the display screen. The map 64 can be created in real time, as the positional coordinate data and the snow depth data is gathered on the site and could also be color-coded (or similar technique) to more clearly illustrate snow depth information. Software for generating color-coded maps is available from RDS Technology Ltd, Gloucestershire, England and is suitable for this purpose.

The ground and snow surface data can be processed and compared into various approximated graphical representations or maps, such as by surface modeling. Other processing and data presentation can be by other known means, such as, for example, those means descπbed m U.S. Patent No. 5,761,095.

In addition to mapping snow depth based on GPS position data, other measurable parameters can be mapped based on GPS position data as well. For example, local slope inclination can be mapped as can groomer configuration settings as the groomer traverses the ski slope terrain.

Preferably, the on-board computer 60 is packaged in such a way that it can be installed in a rovmg vehicle such as the snow grooming vehicle 56. In preferred embodiments, the computer 60 is located in the cab of the snow grooming vehicle 56, where it is easily accessible to the operator

The preferred on-board computer 60 is commercially available from RDS Technology Ltd, Gloucestershire, England and sold under the model BPM2- KJK, Pro- Series. However, any computer type device with the capacity of receiving signals such as analog input, digital input, seπal commumcation, CAN protocol communication, etc. could be used in the apparatus 50 so as to control the GPS assembly 52 and the GPR assembly 54 It is contemplated that the on-board data manipulating micro-processors and associated software and/or data storage modules may be omitted from the apparatus 50 or may be located outside of the snow grooming vehicle 56 such as in administrative center Additionally, the raw, unprocessed GPS and GPR data signals could be transmitted directly, by means of RF transmissions, to a central data processing center

In preferred embodiments, the work implement 70 in the form of a snow groomer (blade, tiller, etc ) is movably attached at the rear of the snow grooming vehicle 56 so that the implement 70 is pulled by the snow grooming vehicle 56 to groom the snow into desired surface contours and/or snow depth distributions as the snow grooming vehicle 56 traverses the snow surface 42 as for example of a ski slope (Fig. 6). The implement 70 is manually movable by the operator of the snow grooming vehicle 56, wherein the operator may control the position and movement of the implement 70 relative to the ground and snow surfaces 40, 42. However, it may be preferable for the implement 70 to be controllably moved by the on-board computer 60 depending on the depth of the snow, temperature, or other measured parameters. In addition, implement 70 may be controlled by a pre-set program that is keyed to the location of groomer 56 on the ski slope.

For example, a particular implement set-up could be defined for a desired snow depth and the database could be used as referential information. Software could manipulate the snow depth database to create command signals to match the snow depth set-up for each known positional coordinate. When the snow groomer is operated, the GPS would send the actual positional coordinate to a controller, which in turn would send the pre-defined commands for this particular positional coordinate to electrical components such as valve coils, pump coils, motors and others needed by the implement to function. These commands could be current or voltage signals; however, any other known signal for transmitting pre-defined commands created by various types of software could be used.

Operation As the snow grooming vehicle 56 travels in the forward direction (upward and to the left as shown by the arrow in Fig. 6), position data and snow depth data can be recorded simultaneously at regular intervals based on some particular measurable parameter. For example, data can be recorded at any regular time intervals or at any regular intervals of the distance traveled by the snow grooming vehicle 56 carrying the GPS and GPR assemblies 52, 54, respectively. In the preferred embodiments, positional coordinate data and snow depth data are recorded about every three feet of travel by the snow grooming vehicle 56. Position data is measured as described above by the GPS assembly 52. The GPR assembly 54 measures data in the following manner.

The transducer 66 of the GPR assembly 54 is externally attached to the snow grooming vehicle 56 in such a manner that it transmits pulses of ultra high frequency radio waves (microwave electromagnetic energy) 67 at an appropriate angle so as to achieve desired penetration into the ground. While those skilled in the art would appreciate that any suitable frequency of radio waves 67 may be used, a frequency between about 500-1,000 MHz is preferred. As for the angle of incidence of those radio waves 67 to the ground, it is preferred that they be aimed directly to the target area, or at least as directly to the target area as possible. However, those skilled in the art will readily appreciate that radio waves 67 also may be aimed at an angle to the ground where needed.

The transmitted waves 67 are reflected from various buried objects or distinct subsurface interfaces between different earth materials, such as the interface between snow and the ground. As described above, the frequency of the transmitted waves 67 can be varied to adjust the depth of penetration of the waves, to thereby control the depth to which the GPR assembly 54 can discern subsurface features. The transducer 66 then receives the reflected waves 69 and stores the data associated with them in the electronic module 68, which in turn, communicates the snow depth data as the voltage analog signal to the onboard computer 60. Then, the position information sent from the GPS assembly 52 and the voltage signal sent from the GPR assembly 54 is received, interpreted and processed by the onboard computer 60. The computer 60 creates the database containing snow depth for each particular positional coordinate traversed by the snow grooming vehicle 56. The dedicated software of the computer 60 manipulates the created database to generate the snow map 64. These steps are generally shown in Fig. 8. The snow map 64 is then displayed on the display screen of the on-board computer 60 and can be used to plan snow grooming work or to and analyze the snow grooming result.

In addition, after generation of the snow map 64, a ski resort could use the map for a variety of purposes. For example, the resort could analyze the data to optimally plan future snow grooming work or to study past grooming operations. In addition, the resort could use the data to plan snow-making efforts and coordinate equipment needs. With the snow map 64, the resort might optimize snow depth to stretch the operating season. Maps may be compared to one another to evaluate changes in snow depth and to monitor snow deterioration.

A map of this type may also be useful in other non-ski-related environments. For example, snow removal industries may benefit from the present invention. So might snowmobile trail grooming companies, snowmobile industries, and other snow-related industries where knowing the snow depth at a particular location provides added value. Also, other non-snow-related industries (i.e., agriculture) may also benefit from the system described.

The following table sets forth the equipment preferred for use with the apparatus described herein. While specific manufacturers and parts are called-out, it should be kept in mind that any suitable alternative may be substituted therefor without deviating from the scope and spirit of the present invention.

While the principles of the invention have been made clear in the illustrative embodiments set forth above, it will be apparent to those skilled in the art that various modifications may be made to the structure, arrangement, proportion, elements, materials, and components used in the practice of the invention

It will thus be seen that the objects of this invention have been fully and effectively accomplished. It will be realized, however, that the foregoing preferred specific embodiments have been shown and described for the purpose of illustrating the functional and structural principles of this invention and are subject to change without departure from such principles. Therefore, this invention includes all modifications encompassed within the spirit and scope of the following claims.

Claims

What is claimed is:

1. An apparatus for measuring snow depth at a predetermined location, comprising: a mobile vehicle; a global positioning system capable of determining a latitude, a longitude, and an elevation of the mobile vehicle at the predetermined location and of generating a positional data signal representative thereof; a ground penetrating radar capable of measuring the snow depth at the predetermined location and of generating a snow depth data signal representative thereof; and a computer in communication with the global positioning system and the ground penetrating radar, capable of linking the positional data signal and the snow depth data signal for the predetermined location.

2. The apparatus of claim 1, wherein: the global positioning system is capable of determining the latitude, longitude, and elevation of the mobile vehicle at a number of the predetermined locations and of generating the positional data signals therefor; the ground penetrating radar is capable of measuring the snow depth at each of the number of predetermined locations and of generating the snow depth data signals therefor; and the computer is capable of linking the positional data signals and the snow depth data signals for each of the number of predetermined locations to compile a database thereof.

3. The apparatus of claim 2, wherein the computer is capable of generating a map from the database of linked positional data signals and snow depth data signals.

4. The apparatus of claim 1, further comprising: a display in communication with the computer capable of displaying at least one of the positional data signal and the snow depth data signal; and a data module for storing the positional data signal and the snow depth data signal in a memory.

5. The apparatus of claim 3, further comprising: a display in communication with the computer capable of displaying the map; and a data module for storing the positional data signals and the snow depth data signals in a memory.

6. A snow groomer, comprising: a frame; a passenger cab positioned on the frame; at least one track positioned below the passenger cab on the frame to move the snow groomer across a snow surface; a global positioning system mounted on the snow groomer to determine a latitude, a longitude, and an elevation of the snow groomer at a predetermined location and to generate a positional data signal representative thereof; a ground penetrating radar to measure snow depth at the predetermined location and to generate a snow depth data signal representative thereof; and a computer in communication with the global positioning system and the ground penetrating radar to link the positional data signal and the snow depth data signal for the predetermined location.

7. The snow groomer of claim 6, wherein: the global positioning system determines the latitude, longitude, and the elevation of the snow groomer at a number of the predetermined locations and generates positional data signals therefor; the ground penetrating radar measures the snow depth at each of the number of predetermined locations and generates snow depth data signals therefor; and the computer links the positional data signals and the snow depth data signals for each of the number of predetermined locations and compiles a database thereof.

8. The snow groomer of claim 7, wherein the computer generates a map from the database of linked positional data signals and snow depth data signals.

9. The snow groomer of claim 6, further comprising: a display in communication with the computer to display at least one of the positional data and the snow depth signal; and a data module for storing the positional data signal and the snow depth data signal in a memory.

10. The snow groomer of claim 8, further comprising: a display in communication with the computer to display the map; and a data module for storing the positional data signals and the snow depth data signals in a memory.

11. The snow groomer of claim 10, further comprising: a working implement positioned on the frame to manipulate snow at the snow surface, wherein the working implement is in communication with and controlled by the computer according to the map and a predetermined set of instructions.

12. A method of measuring snow depth, comprising: linking a global positioning system, a ground penetrating radar, and a computer so that they are in communication with one another; moving at least the global positioning system and the ground penetrating radar to a predetermined location; determining a latitude, a longitude, and an elevation at the predetermined location using the global positioning system; generating a positional data signal representative of the latitude, the longitude, and the elevation determined at the predetermined location; measuring the snow depth at the predetermined location using the ground penetrating radar; generating a snow depth data signal representative of the snow depth measured at the predetermined location; transferring the positional data signal to the computer; transferring the snow depth data signal to the computer; and linking the positional data signal and the snow depth data signal for the predetermined location using the computer.

13. The method of claim 12. further comprising: moving at least the global positioning system and the ground penetrating radar to a number of subsequent predetermined locations; determining the latitude, the longitude, and the elevation at each of the number of subsequent predetermined locations using the global positioning system; generating positional data signals representative of the latitude, the longitude, and the elevation determined at each of the number of subsequent predetermined locations; measuring the snow depth at each of the number of subsequent predetermined locations using the ground penetrating radar; generating snow depth data signals representative of the snow depths measured at each of the number of subsequent predetermined locations; transferring the positional data signals to the computer; transferring the snow depth data signals to the computer; linking the positional data signals and the snow depth data signals for each of the number of subsequent predetermined locations using the computer; and compiling a database of the positional data signals and the snow depth data signals.

14. The method of claim 13, further comprising: generating a map from the database of linked positional data signals and snow depth data signals.

15. The method of claim 12, further comprising: displaying at least one of the positional data signal and the snow depth data signal; and storing the positional data signal and the snow depth data signal.

16. The method of claim 14, further comprising: displaying the map; and storing the map.

17. A method of measuring snow depth while grooming a snow surface with a snow groomer, comprising: providing a global positioning system, a ground penetrating radar, and a computer on board of the snow groomer; linking the global positioning system, the ground penetrating radar, and the computer together so that they are in communication with one another; moving the snow groomer to a predetermined location; determining a latitude, a longitude, and an elevation using the global positioning system; generating a positional data signal representative of the latitude, the longitude, and the elevation at the predetermined location; measuring the snow depth at the predetermined location using the ground penetrating radar; generating a snow depth data signal representative of the snow depth measured at the predetermined location; transferring the positional data signal to the computer; transferring the snow depth data signal to the computer; and linking the positional data signal and the snow depth data signal using the computer.

18. The method of claim 17, further comprising: moving the snow groomer to a number of subsequent predetermined locations; determining the latitude, the longitude, and the elevation at each of the number of subsequent predetermined locations using the global positioning system; generating positional data signals representative of the latitude, the longitude, and the elevation determined at each of the number of subsequent predetermined locations; measuring the snow depth at each of the number of subsequent predetermined locations using the ground penetrating radar; generating snow depth data signals representative of the snow depths measured at each of the number of subsequent predetermined locations; transferring the positional data signals to the computer; transferring the snow depth data signals to the computer; linking the positional data signals and the snow depth signals for each of the number of subsequent predetermined locations using the computer; and compiling a database of the positional data signals and the snow depth data signals.

19. The method of claim 18, further comprising: generating a map from the database linked positional data signals and snow depth data signals.

20. The method of claim 17, further comprising: displaying at least one of the positional data signal and the snow depth data signal on the snow groomer; and storing the positional data signal and the snow depth data signal.

21. The method of claim 19, further comprising: displaying the map; and storing the map.

22. The method of claim 21 , further comprising: controlling the operation of a working implement on the snow groomer according to the map and a predetermined set of instructions in the computer.