AU2021103193A4 - System for measuring sea ice thickness - Google Patents

System for measuring sea ice thickness Download PDF

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Publication number
AU2021103193A4
AU2021103193A4 AU2021103193A AU2021103193A AU2021103193A4 AU 2021103193 A4 AU2021103193 A4 AU 2021103193A4 AU 2021103193 A AU2021103193 A AU 2021103193A AU 2021103193 A AU2021103193 A AU 2021103193A AU 2021103193 A4 AU2021103193 A4 AU 2021103193A4
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AU
Australia
Prior art keywords
sea ice
height
sea
measuring
ice thickness
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Ceased
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AU2021103193A
Inventor
Jingxue GUO
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POLAR RESEARCH INSTITUTE OF CHINA
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Polar Res Institute Of China
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B17/00—Measuring arrangements characterised by the use of infrasonic, sonic or ultrasonic vibrations
    • G01B17/02—Measuring arrangements characterised by the use of infrasonic, sonic or ultrasonic vibrations for measuring thickness
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B15/00—Measuring arrangements characterised by the use of electromagnetic waves or particle radiation, e.g. by the use of microwaves, X-rays, gamma rays or electrons
    • G01B15/02—Measuring arrangements characterised by the use of electromagnetic waves or particle radiation, e.g. by the use of microwaves, X-rays, gamma rays or electrons for measuring thickness
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/86—Combinations of radar systems with non-radar systems, e.g. sonar, direction finder
    • G01S13/862—Combination of radar systems with sonar systems
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S15/00—Systems using the reflection or reradiation of acoustic waves, e.g. sonar systems
    • G01S15/02—Systems using the reflection or reradiation of acoustic waves, e.g. sonar systems using reflection of acoustic waves
    • G01S15/06—Systems determining the position data of a target
    • G01S15/08—Systems for measuring distance only
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S15/00—Systems using the reflection or reradiation of acoustic waves, e.g. sonar systems
    • G01S15/88—Sonar systems specially adapted for specific applications

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  • Engineering & Computer Science (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Acoustics & Sound (AREA)
  • Electromagnetism (AREA)
  • Length Measuring Devices By Optical Means (AREA)

Abstract

OF THE DISCLOSURE (Figure 1) 'A The present disclosure provides a system for measuring sea ice thickness, which comprises a body, wherein the body comprises: an electromagnetic inductor, which transmits and receives electromagnetic field signals perpendicularly to sea ice; a sonar device, which transmits and receives sonar signals perpendicularly to the sea ice; and a control unit, which is in data connection with the electromagnetic inductor and the sonar device, wherein the control unit calculates a first height from the body to an interface between sea ice and sea water according to the electromagnetic field signals from the electromagnetic inductor, calculates a second height from the body to the upper surface of sea ice according to the sonar signals, and acquires the sea ice thickness by subtracting the second height from the first height. The present disclosure correspondingly provides a method for measuring sea ice thickness. The present disclosure realizes repeated continuous shipboard observation of the large-range sea ice and can precisely measure sea ice thickness. 3.66m EM3121 Ix Rx conductivity h, z air conductivity 0 snow conductivity ai tl=z-hi sea ice conductivity o7 sea water FIG.2

Description

3.66m
EM3121
Ix Rx
conductivity
h, z air conductivity 0 snow
conductivity ai tl=z-hi sea ice
conductivity o7 sea water
FIG.2
SYSTEM FOR MEASURING SEA ICE THICKNESS TECHNICAL FIELD
[0001] The present disclosure relates to the field of ocean monitoring, in particular to a novel system for measuring sea ice thickness and a method for measuring sea ice thickness using the system.
BACKGROUNDART
[0002] Sea ice thickness and its variation is a hot and technical difficulty in the field of global change research, and scientists from all over the world are working hard to find technical methods to solve this problem.
[0003] Sea ice thickness is particularly significant and sensitive to the coupling process of atmosphere-sea ice-ocean, and directly determines the exchange process and rate of energy and matter between sea and air, which dominates the thermodynamic and dynamic characteristics of sea ice and influences the movement, deformation, freezing and melting process of sea ice. At present, there are mainly the following technologies for monitoring and measuring sea ice thickness:
[0004] satellite remote sensing technology, in which with the rapid development of satellite technology and spaceborne sensor technology, the remote sensing application of sea ice thickness has made remarkable progress, but up to now, no sensor can directly observe sea ice thickness;
[0005] underwater looking-up sonar technology, in which the underwater looking-up sonar technology belongs to the classic method for observing ice thickness, carries the looking-up sonar device on the submarine or underwater robot platform, and the acquired sea ice thickness data is widely used by scientists, but the observation accuracy of this technology is limited by the position of an underwater transducer and the influence of water temperature, tide and air pressure changes;
[0006] electromagnetic induction technology, in which the technology has the advantages of non-contact and fast working speed, but there is no commercial product of a device for detecting ice thickness through electromagnetic induction.
[0007] Therefore, a system for measuring sea ice thickness with a high-precision and compact structure is urgently needed in the industry.
SUMMARY
[0008] In view of this, the present disclosure provides a system for measuring sea ice thickness, which comprises a body, wherein the body comprises: an electromagnetic inductor, which transmits and receives electromagnetic field signals perpendicularly to sea ice; a sonar device, which transmits and receives sonar signals perpendicularly to the sea ice; and a control unit, which is in data connection with the electromagnetic inductor and the sonar device, wherein the control unit calculates a first height from the body to an interface between sea ice and sea water according to the electromagnetic field signals from the electromagnetic inductor, calculates a second height from the body to the upper surface of sea ice according to the sonar signals, and acquires the sea ice thickness by subtracting the second height from the first height.
[0009] In the above system for measuring sea ice thickness, the body may further comprise: a Global Positioning System GPS device, which is in data connection with the control unit and is configured to acquire the positioning information of the system for measuring the sea ice thickness.
[0010] In the above system for measuring sea ice thickness, the body may further comprise: a storage device, which is in data connection with the control unit and is configured to store data.
[0011] The system for measuring sea ice thickness may further comprise an auxiliary bracket, wherein the auxiliary bracket comprises:a vertical rod; a horizontal rod, which is fixed on the vertical rod perpendicularly to the vertical rod and is provided with a plurality of pulleys on the lower surface of the horizontal rod; a drawstring, which is arranged along the pulleys and fixes the body of the system for measuring sea ice thickness at one end far away from the vertical rod; and a reel elevator, which is provided with a rotating shaft, wherein the other end of the drawstring is fixed on the rotating shaft to adjust the height of the body.
[0012] The above system for measuring sea ice thickness may further comprise a laser, which is in data connection with the control unit and is configured to transmit and receive laser signals perpendicularly to sea water, wherein the control unit calculates a third height from the body to the surface of sea water according to laser signals transmitted and received by the laser to sea water, acquires the height of the ice side of the sea ice by subtracting the second height from the third height, and then calculates the sea ice thickness according to Archimedes law.
[0013] According to another aspect of the present disclosure, there is further provided a method for measuring sea ice thickness, comprising the steps of: transmitting and receiving a first signal perpendicularly to sea ice from a horizontal position; transmitting and receiving a second signal perpendicularly to sea ice from the horizontal position; calculating a first height from the position to the interface between sea ice and sea water according to the first signal, calculating a second height from the position to the upper surface of the sea ice according to the second signal, and acquiring the sea ice thickness by subtracting the second height from the first height.
[0014] The above sea ice thickness measuring method may further comprise the step of measuring global positioning GPS information of the position.
[0015] The above sea ice thickness measuring method may further comprise: retrieving the snow thickness at the position according to the GPS information, and subtracting the snow thickness from the acquired sea ice thickness to eliminate the influence of snow on the sea ice thickness.
[0016] The above sea ice thickness measuring method may further comprise: transmitting and receiving a third signal perpendicularly to sea water from the horizontal position; and calculating a third height from the horizontal position to the surface of the sea water according to the third signal, acquiring the height of the ice side of the sea ice by subtracting the second height from the third height, and then calculating the sea ice thickness according to the Archimedes law.
[0017] It should be understood that both the above general description and the following detailed description of the present disclosure are exemplary and explanatory, and are intended to provide further explanation for the present disclosure as described in claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The accompanying drawings, which are included to provide a further understanding of the present disclosure and are incorporated in and constitute a part of this application, illustrate embodiments of the present disclosure and serve to explain the principles of the present disclosure together with the description.
[0019] In the drawings:
[0020] FIG. 1 shows a structural diagram of a system for measuring sea ice thickness according to an embodiment of the present disclosure;
[0021] FIG. 2 shows a schematic diagram of measuring sea ice thickness according to an embodiment of the present disclosure.
[0022] FIG. 3 shows a schematic diagram of an auxiliary bracket of a system for measuring sea ice thickness according to an embodiment of the present disclosure.
[0023] FIG. 4 shows a schematic diagram of measuring sea ice thickness according to another embodiment of the present disclosure.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0024] Embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings.
[0025] FIG. 1 shows a structural diagram of a system for measuring sea ice thickness according to an embodiment of the present disclosure. As shown in FIG. 1, the system can at least comprise an electromagnetic inductor 101, a sonar device 102, a laser 103, a GPS device 104, a power supply 105, a control unit 106 and a computer 107. The specific operation and other technical contents of these devices will be further explained in combination with embodiments of a specific measuring method.
[0026] Embodiment 1
[0027] FIG. 2 shows an embodiment of a method for measuring sea ice thickness according to the present disclosure.
[0028] The basis of applying the electromagnetic induction principle to measure sea ice thickness is that there is a significant difference between sea ice conductivity and sea water conductivity, that is, the sea ice conductivity ranges from 0 to 300 mS/m, while the sea water conductivity usually ranges from 2000 to 3000 mS/m. The transmitting coil of an electromagnetic induction sensor produces a low-frequency magnetic field (primary field), which causes sea ice to induce eddy current. The eddy current field causes a secondary magnetic field, which is detected by a receiving coil. Because the sea ice layer has high resistance, the sea water layer has low resistance, and the resistivity ratio of the two layers is large. Therefore, the position of the interface between the two layers can be accurately calculated when the conductivity value of each layer is known.
[0029] As shown in FIG. 2, the system for measuring sea ice thickness 201 shown in FIG. 1 is provided above sea ice. The electromagnetic inductor 101 transmits and receives electromagnetic field signals perpendicularly to sea ice, and the sonar device 102 transmits and receives sonar signals perpendicularly to sea ice. The sonar device 102 is configured to measure the accurate height from the system 201 to the ice surface, that is, the height h in FIG. 2. The electromagnetic inductor 101 is configured to measure the height from the system 201 to the interface between sea ice and sea water based on the above principle, that is, the height z in FIG. 2.
[0030] Returning to FIG. 1, the data collected by the electromagnetic inductor 101 and the sonar device 102 will be transmitted to the control unit 103. The control unit can calculate the height z between the system 201 and the interface between sea ice and sea water according to the electromagnetic field signal from the electromagnetic inductor 101, and calculate the height hi between the system 201 and sea ice according to the sonar signal from the sonar device 102. Sea ice thickness can be roughly acquired by subtracting the height hi from the height z.
[0031] In addition, as shown in FIG. 1, the control unit 106 is also connected with a computer 107 for storing and displaying related data.
[0032] In the process of field measurement of polar environment, the measurement operation is usually carried out by ship. In order to hang the system for measuring sea ice thickness on the outboard side of the ship, a preferred embodiment of the present disclosure further provides an auxiliary bracket 301, as shown in FIG. 3.
[0033] Turning to FIG. 3, the auxiliary bracket 301 may comprise a vertical rod 302, a horizontal rod 303 fixed on the vertical rod perpendicularly to the vertical rod, a plurality of pulleys 304 provided on the lower surface of the horizontal rod, a drawstring 306 arranged along the pulleys and fixing the body of the system for measuring sea ice thickness at one end far away from the vertical rod, and a reel elevator 305 provided with a rotating shaft, wherein the other end of the drawstring is fixed on the rotating shaft to adjust the height of the body of the system for measuring sea ice thickness. During measurement, the body can be fixed in a specific wooden frame, and the wooden frame can be placed on the outboard side of the ship. The height of the instrument can be controlled by the reel elevator 305. Generally, the horizontal rod 304 requires that the minimum distance between the body and the hull is 8m, so that the detection result is not affected by the hull itself and the influence of the ship on ice crushing is minimized. In addition, two taut ropes are used to fix both sides of the wooden frame on the ship, which can effectively reduce the swing of the measuring system in the air when the ship breaks ice. The bracket system can also control the attitude of the instrument and avoid the influence of conductors such as the hull on the electromagnetic field.
[0034] Embodiment 2
[0035] FIG. 4 shows another embodiment of the present disclosure, which relates to another method for measuring sea ice thickness. The method mainly uses the sonar device 102 and the laser 103 shown in FIG. 1. According to this embodiment, the system for measuring sea ice thickness 401 should at least comprise a sonar device 102 and a laser 103. Turning to FIG. 4, as in Embodiment 1, the system for measuring sea ice thickness 401 of the present disclosure, i.e., the sonar device 102 and the laser 103, is fixed above the sea ice. In the same way as in Embodiment 1, the sonar device 102 can be used to measure the height Hi from the sea water surface to the system 401 and the height H2 from the upper surface of sea ice to the system 401. At the same time, the height Hi from the sea water surface to the system 401 and the height H2 from the upper surface of sea ice to the system 401 can be measured by the laser 103 in a similar way. The height H of the ice side can be obtained by H1-H2. Then, Archimedes buoyancy law can be used to calculate sea ice thickness.
[0036 In practice, for example, the system 401 travels in the direction as shown in FIG. 4, so that the system 401 first measures the height H and then measures the height H2. At this time, because the reflection characteristics of sea water and sea ice to laser light are obviously different, the echo signal waveform characteristics of the reflected laser signal received by the laser 103 will change obviously, for example, about three times. Specifically, the control unit 106 can detect the change of the echo signal by detecting the amplitude or frequency information of the reflected laser signal. According to this change, the system 401 can accurately distinguish whether the height measured from the laser signal is HIor H2.
[0037] Specifically, the sea ice thickness T can be obtained according to the following formula:
[0038] T = - x F- x T
[0039] where pw, pi and p, are the density of sea water, sea ice and snow, F is the height of ice side (including snow), and T, is the thickness of snow.
[0040] Those skilled in the art can understand that the laser 103 can be omitted in the first embodiment without affecting the implementation of this embodiment, and the electromagnetic inductor 101 can also be omitted in the second embodiment without affecting the implementation of this embodiment. In addition, preferably, two sets of independent sea ice thickness data can be obtained by including the above devices 101, 102 and 103 at the same time for mutual verification, so as to extract interference noise signals. In particular, in the case of integrating the above two embodiments, the measurement error of sea ice thickness in the flat ice area can be reduced to less than %, and the measurement error in the ice ridge area can be reduced to less than 20%.
[0041] To sum up, the method realizes repeatable observation of sea ice in a large range and can accurately measure sea ice thickness. The system for measuring sea ice thickness of the present disclosure also has many advantages of high precision, integration and easy operation.
[0042] It will be apparent to those skilled in the art that various modifications and variations can be made to the above exemplary embodiments of the present disclosure without departing from the spirit and scope of the present disclosure. Therefore, it is intended that the present disclosure cover modifications and variations of the present disclosure falling within the scope of the appended claims and their equivalents.

Claims (5)

WHAT IS CLAIMED IS:
1. A system for measuring sea ice thickness, comprising a body, wherein the body comprises:
an electromagnetic inductor, which transmits and receives electromagnetic field signals perpendicularly to sea ice;
a sonar device, which transmits and receives sonar signals perpendicularly to sea ice; and
a control unit, which is in data connection with the electromagnetic inductor and the sonar device,
a laser, which is in data connection with the control unit and is configured to transmit and receive laser signals perpendicularly to sea water;
wherein the control unit calculates a first height from the body to the lower surface of sea ice according to the electromagnetic field signals from the electromagnetic inductor, calculates a second height from the body to the upper surface of sea ice according to the sonar signals, and acquires the sea ice thickness by subtracting the second height from the first height,
wherein the control unit calculates a third height from the body to the surface of sea water according to laser signals transmitted and received by the laser to sea water, acquires the height of the ice side of the sea ice by subtracting the second height from the third height, and then calculates the sea ice thickness according to Archimedes law.
2. The system for measuring sea ice thickness according to claim 1, wherein the body further comprises:
a Global Positioning System GPS device, which is in data connection with the control unit and is configured to acquire the positioning information of the system for measuring the sea ice thickness;
wherein the body further comprises:
a storage device, which is in data connection with the control unit and is configured to store data.
3. The system for measuring sea ice thickness according to claim 1, further comprising an auxiliary bracket, wherein the auxiliary bracket comprises:
a vertical rod;
a horizontal rod, which is fixed on the vertical rod perpendicularly to the vertical rod and is provided with a plurality of pulleys on the lower surface of the horizontal rod;
a drawstring, which is arranged along the pulleys and fixes the body of the system for measuring sea ice thickness at one end far away from the vertical rod; and
a reel elevator, which is provided with a rotating shaft, wherein the other end of the drawstring is fixed on the rotating shaft to adjust the height of the body.
4. A method for measuring sea ice thickness, comprising the steps of:
transmitting and receiving a first signal perpendicularly to sea ice from a horizontal position;
transmitting and receiving a second signal perpendicularly to sea ice from the horizontal position;
calculating a first height from the position to the interface between sea ice and sea water according to the first signal, calculating a second height from the position to the upper surface of the sea ice according to the second signal, and acquiring the sea ice thickness by subtracting the second height from the first height;
transmitting and receiving a third signal perpendicularly to sea water from the horizontal position; and
calculating a third height from the horizontal position to the surface of the sea water according to the third signal, acquiring the height of the ice side of the sea ice by subtracting the second height from the third height, and then calculating the sea ice thickness according to the Archimedes law.
5. The method for measuring sea ice thickness according to claim 4, further comprising:
measuring global positioning GPS information of the position
‌ －‌1‌/4‌－ ‌ ‌ ‌ 08 Jun 2021
DRAWINGS‌ ‌ ‌ ‌ ‌ 2021103193
‌ ‌ ‌ ‌ ‌ FIG.1‌ ‌ ‌ ‌ ‌ ‌ ‌ ‌ ‌ ‌
‌
‌ －‌2‌/4‌－ ‌ ‌ ‌ 08 Jun 2021 2021103193
‌ ‌ FIG.2‌ ‌ ‌
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‌ －‌3‌/4‌－ ‌ ‌ ‌ 08 Jun 2021
‌ ‌ ‌ ‌ ‌ ‌ ‌ ‌ ‌ ‌ 2021103193
‌ ‌ ‌ ‌ ‌ ‌ ‌ ‌ ‌ ‌ ‌ FIG.3‌ ‌
‌
‌ －‌4‌/4‌－ ‌ ‌ ‌ 08 Jun 2021 2021103193
‌ FIG.4‌ ‌ ‌
‌
AU2021103193A 2021-06-08 2021-06-08 System for measuring sea ice thickness Ceased AU2021103193A4 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU2021103193A AU2021103193A4 (en) 2021-06-08 2021-06-08 System for measuring sea ice thickness

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Application Number Priority Date Filing Date Title
AU2021103193A AU2021103193A4 (en) 2021-06-08 2021-06-08 System for measuring sea ice thickness

Publications (1)

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AU2021103193A4 true AU2021103193A4 (en) 2021-08-26

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AU (1) AU2021103193A4 (en)

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