公开(公告)号：US09297922B2

公开(公告)日：2016-03-29

申请号：US13868803

申请日：2013-04-23

Applicant: VALE S.A.

Inventor： Gordon Fox West ,  Peter Whyte Walker ,  Benjamin David Polzer

IPC: G01V3/28 ,  G01V3/10 ,  G01V3/165 ,  G01V3/38 ,  G01V3/30 ,  G01V3/18 ,  G01V3/26

CPC classification number: G01V3/28 ,  G01V3/107 ,  G01V3/165 ,  G01V3/18 ,  G01V3/26 ,  G01V3/30 ,  G01V3/38

Abstract: A method and apparatus is provided for bucking a magnetic field of known geometry and time variation by means of a plurality of bucking loops. It utilizes multiple loops, each of which is energized by an electric current that creates a magnetic field of the known time variation. The multi-loop field forms a bucking magnetic field that better opposes the spatial variation in the known magnetic field over a volume than can the magnetic field from a single loop. The present invention is useful in electromagnetic measurements, where the magnetic field of a controlled source transmitter must be annulled at a magnetic field sensor. It is particularly useful for cases where the magnetic sensor may move relative to the transmitter, such as in certain airborne electromagnetic measurements.

Abstract translation: 提供了一种方法和装置，用于通过多个降压环来抵消已知几何形状和时间变化的磁场。 它利用多个环路，每个环路由一个产生已知时间变化的磁场的电流通电。 多回路磁场形成的屈曲磁场能够比单个环路的磁场能够更好地抵抗已知磁场中的空间变化。 本发明在电磁测量中是有用的，其中受控源发射器的磁场必须在磁场传感器处被取消。 对于磁传感器相对于发射器移动的情况，例如在某些机载电磁测量中，这是特别有用的。

公开(公告)号：US20140285206A1

公开(公告)日：2014-09-25

申请号：US13868803

申请日：2013-04-23

Applicant: VALE S.A.

Inventor： Gordon Fox WEST ,  Peter Whyte Walker ,  Benjamin David Polzer

IPC: G01V3/28

CPC classification number: G01V3/28 ,  G01V3/107 ,  G01V3/165 ,  G01V3/18 ,  G01V3/26 ,  G01V3/30 ,  G01V3/38

Abstract: A method and apparatus is provided for bucking a magnetic field of known geometry and time variation by means of a plurality of bucking loops. It utilizes multiple loops, each of which is energized by an electric current that creates a magnetic field of the known time variation. The multi-loop field forms a bucking magnetic field that better opposes the spatial variation in the known magnetic field over a volume than can the magnetic field from a single loop. The present invention is useful in electromagnetic measurements, where the magnetic field of a controlled source transmitter must be annulled at a magnetic field sensor. It is particularly useful for cases where the magnetic sensor may move relative to the transmitter, such as in certain airborne electromagnetic measurements.

Abstract translation: 提供了一种方法和装置，用于通过多个降压环来抵消已知几何形状和时间变化的磁场。 它利用多个环路，每个环路由一个产生已知时间变化的磁场的电流通电。 多回路磁场形成的屈曲磁场能够比单个环路的磁场能够更好地抵抗已知磁场中的空间变化。 本发明在电磁测量中是有用的，其中受控源发射器的磁场必须在磁场传感器处被取消。 对于磁传感器相对于发射器移动的情况，例如在某些机载电磁测量中，这是特别有用的。

公开(公告)号：US09903976B2

公开(公告)日：2018-02-27

申请号：US14930335

申请日：2015-11-02

Applicant: VALE S.A.

Inventor： Gordon Fox West ,  Peter Whyte Walker ,  Benjamin David Polzer

IPC: G01V3/16 ,  G01V3/165 ,  G01V3/28 ,  G01V3/08 ,  G01V3/26 ,  G01V3/18

CPC classification number: G01V3/165 ,  G01V3/08 ,  G01V3/081 ,  G01V3/083 ,  G01V3/17 ,  G01V3/18 ,  G01V3/26 ,  G01V3/28 ,  G01V2003/084

Abstract: An apparatus for airborne electromagnetic surveying is provided, comprising a central hub defining an equatorial plane, a transmitter loop, and radials connecting the hub to the transmitter loop. The loop generally lies in a plane during flight, and comprises loop sections, some of which are connected with flexible joints allowing the loop to flex out of the plane during lift-offs and landings. A loop section comprises current conducting elements connected to current conducting elements of adjacent loop sections forming a transmitter loop circuit. A radial connects to the hub at a point that is substantially offset from the transmitter loop plane, thereby contributing to the stability of the transmitter loop connection point in an up-down direction relative to the hub. Additionally, a loop section comprising rigid conductive elements retained in a spaced-apart relationship by a frame member is also provided.

公开(公告)号：US09389281B2

公开(公告)日：2016-07-12

申请号：US13868721

申请日：2013-04-23

Applicant: VALE S.A.

Inventor： Gordon Fox West ,  Peter Whyte Walker ,  Benjamin David Polzer

IPC: G01R27/16 ,  G01R33/00 ,  G01R33/025

CPC classification number: G01R33/0017 ,  G01R33/0029 ,  G01R33/025

Abstract: A solution for compensating a magnetic field sensor to permit detection of a small magnetic field in the presence of a large magnetic field is disclosed. A magnetic field sensor detects the magnetic field which produces an analog signal then encoded by an analog to digital converter (ADC) into a digital stream. A controller operating on the digital stream incorporates additional sensor data to create a compensation signal which is sent to a digital to analog (DAC) converter. This compensation signal then modifies the output of the magnetic field sensor before entering the ADC. Compensation is software controlled, and is thus adaptable to numerous conditions requiring compensation. Apart from being easily tunable, the compensation may respond dynamically to changing conditions. The invention has particular application to airborne electromagnetic surveying where small fields scattered from the Earth are measured in the presence of a large transmitted field.

Abstract translation: 公开了用于补偿磁场传感器以允许在存在大磁场的情况下检测小磁场的解决方案。 磁场传感器检测产生模拟信号的磁场，然后由模拟数字转换器（ADC）编码成数字流。 在数字流上操作的控制器包含附加的传感器数据以产生发送到数模（DAC）转换器的补偿信号。 该补偿信号然后在进入ADC之前修改磁场传感器的输出。 补偿是软件控制的，因此适应于需要补偿的许多条件。 除了易于调整外，补偿还可以动态响应不断变化的状况。 本发明特别适用于在大的传播场的存在下测量从地球散射的小场的机载电磁测量。

公开(公告)号：US20140288862A1

公开(公告)日：2014-09-25

申请号：US13868721

申请日：2013-04-23

Applicant: VALE S.A.

Inventor： Gordon Fox WEST ,  Peter Whyte Walker ,  Benjamin David Polzer

IPC: G01R33/00

CPC classification number: G01R33/0017 ,  G01R33/0029 ,  G01R33/025

Abstract: A solution for compensating a magnetic field sensor to permit detection of a small magnetic field in the presence of a large magnetic field is disclosed. A magnetic field sensor detects the magnetic field which produces an analogue signal then encoded by an analogue to digital converter (ADC) into a digital stream. A controller operating on the digital stream incorporates additional sensor data to create a compensation signal which is sent to a digital to analogue (DAC) converter. This compensation signal then modifies the output of the magnetic field sensor before entering the ADC. Compensation is software controlled, and is thus adaptable to numerous conditions requiring compensation. Apart from being easily tunable, the compensation may respond dynamically to changing conditions. The invention has particular application to airborne electromagnetic surveying where small fields scattered from the Earth are measured in the presence of a large transmitted field.

Abstract translation: 公开了用于补偿磁场传感器以允许在存在大磁场的情况下检测小磁场的解决方案。 磁场传感器检测产生模拟信号的磁场，然后由模拟数字转换器（ADC）编码成数字流。 在数字流上操作的控制器包含附加的传感器数据以产生发送到数模（DAC）转换器的补偿信号。 然后，该补偿信号在进入ADC之前修改磁场传感器的输出。 补偿是软件控制的，因此适应于需要补偿的许多条件。 除了易于调整外，补偿还可以动态响应不断变化的状况。 本发明特别适用于在大的传播场的存在下测量从地球散射的小场的机载电磁测量。