Ultrasonic ranging and data telemetry system

• US 4,924,450 A
• Filed: 04/13/1989
• Issued: 05/08/1990
• Est. Priority Date: 03/23/1987
• Status: Expired due to Term

• Current Assignee: Martin Marietta Energy Systems, Inc.
• Original Assignee: Martin Marietta Energy Systems, Inc.
• Inventors: Blair, Michael S., Nowlin, Charles H., Phelps, James E., Brashear, Hugh R., Bauer, Martin L.
• Primary Examiner(s): Moskowitz, Nelson
• Assistant Examiner(s): CAIN, DAVID C
• Application Number:
  US07/338,529
• Time in Patent Office: 390 Days
• Field of Search: 250/336.1, 324/329, 364/516, 367/118, 367/117, 367/127, 367/128, 367/129, 367/908, 367/902
• US Class Current: 367/118
• CPC Class Codes: G01C 15/00 Surveying instruments or accessories not provided for in groups G01C1/00 - G01C13/00
• CPC Class Codes: G01S 15/874 Combination of several spaced transponders or reflectors of known location for determining the position of a receiver G01S15/872 takes precedence
• CPC Class Codes: G01S 5/0009 Transmission of position information to remote stations involving assistance data G01S5/0236
• CPC Class Codes: G01S 5/22 Position of source determined by co-ordinating a plurality of position lines defined by path-difference measurements G01S5/28 takes precedence

Abstract

An ultrasonic ranging and data telemetry system determines a surveyor'"'"'s position and automatically links it with other simultaneously taken survey data. An ultrasonic and radio frequency (rf) transmitter are carried by the surveyor in a backpack. The surveyor'"'"'s position is determined by calculations that use the measured transmission times of an airborne ultrasonic pulse transmitted from the backpack to two or more prepositioned ultrasonic transceivers. Once a second, rf communications are used both to synchronize the ultrasonic pulse transmission-time measurements and to transmit other simultaneously taken survey data. The rf communications are interpreted by a portable receiver and microcomputer which are brought to the property site. A video display attached to the computer provides real-time visual monitoring of the survey progress and site coverage.

Claims

1. A method for surveying a property site comprising the steps of:

(a) positioning a plurality of portable transceivers on or in the vicinity of the property site wherein acoustic line of sight is maintained to at least two of the transceivers from all points of the site;

(b) positioning a survey means on the property site within acoustic line of sight of at least two transceivers;

(c) transmitting an ultrasonic pulse from the survey means;

(d) receiving the ultrasonic pulse at each of the at least two transceivers;

(e) determining time differences which are elapsed times between transmitting the ultrasonic pulse from the survey means and receiving the ultrasonic pulse at each of the at least two transceivers;

(f) determining a relative location of the survey means based on the time difference between transmitting the ultrasonic pulse from the survey means and receiving the ultrasonic pulse at each of the at least two transceivers and the speed of sound;

(g) recording the relative location of the survey means;

(h) moving the survey means to a different location on the site; and

(i) repeating steps (b) through (h) until the survey of the site is complete.

2. The method for surveying according to claim 1 wherein step (a) further comprises the steps of:

positioning a first two portable transceivers on or in the vicinity of the property site; and

positioning additional portable transceivers on or in the vicinity of the property site as needed to maintain an acoustic line of sight to at least two transceivers from all points of the property site wherein the additional transceivers are positioned on a same side of a base line joining and extending beyond the first two transceivers.

3. The method for surveying according to claim 2 wherein step (b) further comprises positioning the survey means to the same side as the additional transceivers with respect to the base line joining and extending beyond the first two transceivers.

4. The method for surveying according to claim 3 further comprising a step after step (f) of determining an unambiguous location of the survey means that is based on the relative location of the survey means and on the positioning of the survey means on the same side as the additional transceivers with respect to the base line joining and extending beyond the first two transceivers.

6. The method for surveying according to claim 1 further comprising the steps of:

sensing information about the site with the survey means;

generating an information signal which represents the information about the site;

transmitting the information signal simultaneously with the ultrasonic pulse from the survey means;

receiving the information signal from the survey means;

determining the information about the site based on the information signal; and

recording the information about the site with the relative position of the survey means.

7. A method as claimed in claim 1, further including the step of determining the speed of sound at the property site.

8. A method as claimed in claim 7, wherein the step of determining the speed of sound comprises the steps of:

positioning a first transceiver at a first location;

positioning a second transceiver at a second location a distance from said first transceiver and in line of sight communication with the first transceiver;

positioning the survey means along the line of sight communication between the first and second transceivers;

transmitting an ultrasonic pulse from the survey means to each of the first and second transceivers;

measuring travel time for the ultrasonic pulse to reach the first and second transceivers, respectively;

adding the travel times measured to obtain a total travel time; and

dividing the distance between the first and second transceivers by the total travel time to determine the speed of sound at the property site.

5. The method for surveying according to claim wherein step (e) further comprises:

starting a timing means in response to transmitting the ultrasonic pulse from the survey means;

stopping the timing means in response to receiving the ultrasonic pulse at each of the at least two transceivers; and

generating time difference signals which represent the elapsed time between transmitting the ultrasonic pulse at the survey means and receiving the ultrasonic pulse at each of the at least two transceivers.

9. A method for surveying a property site comprising the steps of:

(a) positioning a plurality of portable transceivers on or in the vicinity of the property site wherein acoustic line of sight is maintained to at least two of the transceivers from all points of the site;

(b) positioning a survey means on the property site within acoustic line of sight of at least two transceivers;

(c) transmitting an ultrasonic pulse from the survey means;

(d) receiving the ultrasonic pulse at each of the at least two receivers;

(e) determining a time difference between transmitting the ultrasonic pulse from the survey means and receiving the ultrasonic pulse at each of the at least two transceivers;

(f) determining a relative location of the survey means based on the time difference between transmitting the ultrasonic pulse from the survey means and receiving the ultrasonic pulse at each of the at least two transceivers and the speed of sound comprising the further steps;

(i) determining a distance P_k (k=1,2,3 . . . ) between the survey means and each of the at least two transceivers;

(ii) approximating a location (X_tip, Y_tip) of the survey means;

(iii) calculating a distance H_k (k=1,2,3 . . . ) between the approximated location (X_tip, Y_tip) and each of the at least two transceivers located at (X_k, Y_k) according to the equation ##EQU2## (iv) calculating a total T based upon the measured distance P_k and the calculated distance H_k according to the equation

space="preserve" listing-type="equation">T=Σ

(H.sub.k -P.sub.k).sup.2

wherein k=1,2,3 . . . ; and

(v) repeating steps (ii) through (iv) until total T is at a minimum, thereby indicating that (X_tip, Y_tip) is the location of the survey means;

(g) recording the relative location of the survey means;

(h) moving the survey means to a different location on the site; and

(i) repeating steps (b) through (h) until survey of the site is complete.

10. A method as claimed in claim 9, wherein said step of determining as recited in step (i) includes the steps of:

transmitting an ultrasonic pulse from the survey means to each of the at least two transceivers;

measuring travel time for the ultrasonic pulse to reach each of the at least two transceivers; and

multiplying each of the measured travel times by the speed of sound.

11. A method for surveying a property site, comprising the steps of:

(a) positioning a first two portable transceivers on or in the vicinity of the property site;

(b) positioning additional portable transceivers on or in the vicinity of the property site as needed to maintain an acoustic line of sight to at least two transceivers from all points of the property site wherein the additional transceivers are positioned on a same side of a base line joining and extending beyond the first two transceivers;

(c) determining the positions of the transceivers with respect to the property site and with respect to each other;

(d) recording the positions of the transceivers in a recording means;

(e) positioning a survey means on the property site within acoustic line of sight of at least two transceivers and to the same side as the additional transceivers with respect to the base line joining and extending beyond the first two transceivers;

(f) sensing information about the property site with the survey means;

(g) generating an information signal which represents the information about the property site;

(h) transmitting an ultrasonic pulse, a radio frequency pulse and the information signal simultaneously from the survey means;

(i) receiving the radio frequency pulse substantially simultaneously at the at least two transceivers;

(j) simultaneously starting first and second timing means in response to receiving the radio frequency pulse at each of the at least two transceivers;

(k) receiving the ultrasonic pulse at each of the at least two transceivers;

(1) stopping first the timing means in response to receiving the ultrasonic pulse at one of the at least two transceivers and stopping the second timing means in response to receiving the ultrasonic pulse at the other of the at least two transceivers;

(m) generating time difference signals which represent the elapsed times between receiving the radio frequency pulse and receiving the ultrasonic pulse at each of the at least two transceivers;

(n) transmitting the time difference signals to a correlating means;

(o) determining the distance of the survey means from each of the at least two transceivers by using the time difference signals and the speed of sound;

(p) determining the relative location of the survey means on the property site based on the distance of the survey means from each of the at least two transceivers;

(q) determining an unambiguous location of the survey means that is based on the relative location on the survey means and on the positioning of the survey means on the same side as the additional transceivers with the respect to the base line joining and extending beyond the first two transceivers;

(r) receiving the information signal from the survey means;

(s) determining the information about the property site based on the information signal;

(t) recording the unambiguous location of the survey means and the information about the property site in a recording means;

(u) displaying the unambiguous location of the survey means, the information about the property site and the position of the transceivers on a display means;

(v) moving the survey means to a different location on the property site;

(w) repeating steps (e) through (v) until the survey of the property site is complete; and

(x) making a map of the property site based upon each of the absolute location marks and each of the information marks on the display means, whereby the map shows the information about the property site and the location where the survey means sensed the information.

12. An apparatus for surveying a property site comprising:

a plurality of portable transceivers positioned or on in the vicinity of the property site wherein acoustic line of sight is maintained to at least two of said transceivers from all points on the site;

a survey means positioned on the property site within acoustic line of sight of at least two of said transceivers and for transmitting an ultrasonic pulse;

means for determining a time difference between the time the survey means transmits the ultrasonic pulse and the time each of the at least two transceivers receives the ultrasonic pulse and for generating a time difference signal from each of the at least two transceivers;

a correlating means for receiving the time difference signals and for determining a relative location of the survey means based on the time differences and the speed of sound;

a recording means for recording the relative location of the survey means; and

means for moving the survey means to a different position on the site.

13. The apparatus of claim 12 wherein said transceivers further comprise:

a timer for measuring the time difference between the time when said survey means transmits the ultrasonic pulse and the time when said transceiver receives the ultrasonic pulse;

a starting means for starting said timer in response to said survey means transmitting the ultrasonic pulse;

a stopping means for stopping said timer in response to said transceiver receiving the ultrasonic pulse; and

a time difference generating means for generating a time difference signal which represents the time difference measured by said timer.

14. The apparatus of claim 12 further comprising means for sensing characteristics of the property site as said survey means moves across the property site.

15. The apparatus of claim 14 wherein said means for recording simultaneously records the relative location and the characteristics of the property site.