Abstract: A directional filter for processing full-tensor gradiometer data is described. The filter processes input data using a method comprising receiving geophysical data collected based on characteristics of geographic features in an environment, and applying a directional filter to the received geophysical data in a first instance so as to provide first filtered data. A filtering direction of the directional filter is determined based on properties in the received geophysical data. The method also includes updating the filtering direction based on properties in the first filtered data, applying the directional filter to the received geophysical data in a subsequent instance using the updated filtering direction so as to provide subsequent filtered data, and based on the updated filtering direction having a subsequent update less than a threshold, outputting directionally filtered data. The subsequent update is determined due to properties in the subsequent filtered data output from the subsequent instance.

Abstract: A directional filter for processing full-tensor gradiometer data is described. The filter processes input data using a method comprising receiving geophysical data collected based on characteristics of geographic features in an environment, and applying a directional filter to the received geophysical data in a first instance so as to provide first filtered data. A filtering direction of the directional filter is determined based on properties in the received geophysical data. The method also includes updating the filtering direction based on properties in the first filtered data, applying the directional filter to the received geophysical data in a subsequent instance using the updated filtering direction so as to provide subsequent filtered data, and based on the updated filtering direction having a subsequent update less than a threshold, outputting directionally filtered data. The subsequent update is determined due to properties in the subsequent filtered data output from the subsequent instance.

Abstract: An accelerometer and rate sensor package to aid gravity gradiometers is provided. The accelerometer and rate sensor package is mounted directly on or within a gravity gradiometer instrument (GGI). Outputs from the sensors can be used to reduce unwanted noise due to angular rotational rates, angular accelerations and linear accelerations that may be coupled to the GGI. Since the sensor assembly is directly mounted on or within the GGI, the sensor assembly is coupled to the GGI and senses the acceleration and angular rates as seen by the GGI. Thus, outputs from the GGI can be corrected more effectively using the sensor assembly's outputs.

Abstract: A method and system for synchronizing geophysical survey data is provided. Detection of geophysically significant subsurface anomalies potentially associated with ore bodies or hydrocarbon deposits can be made by vehicle mounted surface or airborne regional gravitational studies. Recorded geophysical survey data is processed to synchronize data collected by various sensors. Data from the various sensors is synchronized based on position coordinates corresponding to locations where the data was collected. In this manner, at one specific location on Earth, the electromagnetic reading, magnetometer reading, gravimeter reading, and altimeter reading can all be associated together so that many characteristics of the specific location can be identified.

Abstract: An accelerometer and rate sensor package to aid gravity gradiometers is provided. The accelerometer and rate sensor package is mounted directly on or within a gravity gradiometer instrument (GGI). Outputs from the sensors can be used to reduce unwanted noise due to angular rotational rates, angular accelerations and linear accelerations that may be coupled to the GGI. Since the sensor assembly is directly mounted on or within the GGI, the sensor assembly is coupled to the GGI and senses the acceleration and angular rates as seen by the GGI. Thus, outputs from the GGI can be corrected more effectively using the sensor assembly's outputs.

Abstract: An accelerometer and rate sensor package to aid gravity gradiometers is provided. The accelerometer and rate sensor package is mounted directly on or within a gravity gradiometer instrument (GGI). Outputs from the sensors can be used to reduce unwanted noise due to angular rotational rates, angular accelerations and linear accelerations that may be coupled to the GGI. Since the sensor assembly is directly mounted on or within the GGI, the sensor assembly is coupled to the GGI and senses the acceleration and angular rates as seen by the GGI. Thus, outputs from the GGI can be corrected more effectively using the sensor assembly's outputs.

Abstract: A geophysical survey is conducted, using specialized instruments, to measure the gravity field by flying over a terrain of interest. A series of nominally parallel survey lines can be flown until a total region to be surveyed has been covered. The geophysical survey data is collected using an airship or self-propelled lighter-than-air craft sometimes referred to as a dirigible or blimp. In particular, a rigid airship may be used, that includes all extensions, like fins and a control car, attached to a rigid frame.

Abstract: A method and system for processing geophysical survey data is provided. Gravity gradiometry data is processed by approximating density values of terrain signals to remove contributions of the terrain from the gravity gradiometry data. Initially, a predicted gravity gradient data set for a geographical area is calculated using terrain data with unit density. Next, a mathematical transformation is applied to recorded gravity gradiometer data of the geographical area and the predicted gravity gradiometry data. The transformation divides the data into component sub-functions so that each component function can be processed separately. The component sub-functions are processed to estimate densities of the geographical area. Then, using all the estimated densities, gravity gradients due to all of the terrain can be calculated, and subtracted from the recorded gravity gradient signals to reveal gravity gradients due to subsurface masses, for example.

Abstract: A method and system for evaluating geophysical survey data is provided. Two neighboring flight paths of a geophysical survey are likely to have geophysical characteristics in common because neighboring flight paths cover geographic areas in a close proximity to one another. As such, neighboring flight paths will likely have similar geophysical characteristics and similar recorded data. Therefore, errors in data can be estimated by comparing data recorded from neighboring flight paths. If data from a flight path differs significantly from data recorded from a neighboring flight path, then the data from one or both flight paths may be corrupted and at least one of the survey lines may need to be repeated. This auto evaluate method allows field personnel to judge data close to real time to determine whether to repeat a flight path while still out in the field.