公开(公告)号：US4516230A

公开(公告)日：1985-05-07

申请号：US508232

申请日：1983-08-05

Applicant: Kent J. Goodloe ,  Ralph A. Landrum, Jr.

Inventor： Kent J. Goodloe ,  Ralph A. Landrum, Jr.

IPC: B06B1/18 ,  G01V1/04 ,  G01V1/155 ,  G01V1/16

CPC classification number: B06B1/183 ,  G01V1/04 ,  G01V1/155 ,  Y10S181/401

Abstract: In accordance with an embodiment of this invention, voltages are received from the pilot valve torque motor, the main servo valve and the actuator indicating the value of the torque motor current, spool position and actuator displacement. The received voltages are compared to a preselected threshold value. When one or more of the voltages exceed a threshold value, an attenuator control voltage is generated. An attenuator circuit is coupled between the reference driver signal generator and the DC servo amplifier. The attenuator control voltage, if present, is applied to the attenuator circuit and scales down the reference driver signal as a function of the error signal level thereby to limit the torque motor current and consequently the displacements of the main servo valve spool and actuator shaft.

Abstract translation: 根据本发明的实施例，从先导阀扭矩电动机，主伺服阀和致动器接收电压，指示转矩电动机电流，阀芯位置和致动器位移的值。 将接收的电压与预选阈值进行比较。 当一个或多个电压超过阈值时，产生衰减器控制电压。 衰减器电路耦合在参考驱动器信号发生器和DC伺服放大器之间。 衰减器控制电压（如果存在）被施加到衰减器电路，并且根据误差信号电平降低参考驱动器信号，从而限制转矩电动机电流，从而限制主伺服阀芯和致动器轴的位移。

公开(公告)号：US4715020A

公开(公告)日：1987-12-22

申请号：US925810

申请日：1986-10-29

Applicant: Ralph A. Landrum, Jr.

Inventor： Ralph A. Landrum, Jr.

IPC: G01V1/00

CPC classification number: G01V1/003

Abstract: The invention is a method of performing a plurality of vibratory seismic surveys simultaneously. A plurality of vibratory sources transmit signals into the earth. Each vibratory source successively transmits the same signal, except that an offset phase of the signal is selectively shifted for successive transmissions. The offset phase of the signal transmitted by each vibratory source is selected to enable the signal from each of the vibratory sources to be recovered by data processing.

公开(公告)号：US4567583A

公开(公告)日：1986-01-28

申请号：US535215

申请日：1983-09-23

Applicant: Ralph A. Landrum, Jr.

Inventor： Ralph A. Landrum, Jr.

IPC: G01V1/04

CPC classification number: G01V1/04 ,  Y10S181/401

Abstract: A seismic vibrator for shaking the ground is driven by an input sweep signal. A control signal, which is a function of the output force level of the vibrator, modulates the sweep signal to limit the output force level to a value that will prevent ground decoupling. At the beginning of a sweep, an adaptive preset signal over-rides the control signal during a desired initial time portion of the sweep signal. The preset signal for a given sweep is derived from a sample of the control signal that existed during a specified portion of an immediately previous sweep.

Abstract translation: 用于摇动地面的地震振动器由输入扫描信号驱动。 作为振动器的输出力水平的函数的控制信号调制扫描信号以将输出力水平限制为将防止接地去耦的值。 在扫描开始时，自适应预设信号在扫描信号的期望的初始时间部分期间覆盖控制信号。 给定扫描的预设信号是从在紧接着的上一扫描的指定部分中存在的控制信号的采样导出的。

公开(公告)号：US4344158A

公开(公告)日：1982-08-10

申请号：US223447

申请日：1981-01-08

Applicant: Ralph A. Landrum, Jr. ,  Juan B. Vallhonrat ,  Paul M. Perry

Inventor： Ralph A. Landrum, Jr. ,  Juan B. Vallhonrat ,  Paul M. Perry

IPC: G01V1/28 ,  G01V1/36

CPC classification number: G01V1/364 ,  G01V1/288 ,  G01V2210/32

Abstract: A method is disclosed for improving the signal-to-noise ratio of low level seismic signals resulting from weak acoustic sources. The method has application to the summation of signals from swept-frequency sources. A reference model of the level of a valid seismic signal is built for each of a number of time windows during a seismic-data recording cycle. The model is selected by obtaining the average of the absolute magnitudes for each time window from a number of sweeps to form a set of averages. The median of each set is selected and is padded by a suitable coefficient to provide the reference model for each time window. Subsequently, a normal recording is made. Each data sample amplitude of the recording is compared with the reference model corresponding to the time window that includes the data sample. If the amplitude level of the data sample exceeds the reference model level, that sample is suppressed prior to summing.

Abstract translation: 公开了一种用于改善由弱声源产生的低电平地震信号的信噪比的方法。 该方法适用于扫频信号的求和。 在地震数据记录周期期间，为多个时间窗口中的每一个建立有效地震信号电平的参考模型。 通过从多个扫描获得每个时间窗口的绝对量值的平均值来选择该模型以形成一组平均值。 选择每组的中值，并用合适的系数填充以提供每个时间窗的参考模型。 随后，进行正常记录。 将记录的每个数据样本幅度与包括数据样本的时间窗对应的参考模型进行比较。 如果数据样本的幅度水平超过参考模型级别，则在求和之前抑制该样本。