A method and system for determining concentricity of a multiple layer golf ball are disclosed herein. One or more images of a golf ball are generated using an X-ray source, a camera or a digital detector, and an image intensifier. An edge detection algorithm is preferably utilized. The method also includes calculating Y,Z center coordinates of the a best fit diameter or ellipse of the inner edge layer and outer edge layer of the multiple layer golf ball.

Provided is a rigidity characteristics measuring device that measures the rigidity characteristics of a golf club head. A head fixing jig holds the golf club head with a face surface facing upward. A linear bushing causes an impact rod to drop vertically toward the golf club head. The impact rod is equipped with an acceleration sensor. A computer calculates the rigidity characteristics, e.g., a CT value, of the golf club head, based on a detected value of the acceleration sensor.

An apparatus and method for inspection of at least one of grass, artificial turf, infill, or dirt, on a surface, using optical photographic images from a camera and three-dimensional (“3D”) depth scans using the camera and one or more laser, to create a mask to distinguish aspects of the surface, so that the surface can be measured and analyzed.

A golf ball comprising layers that have from 0.05% to 70% by weight of a radio-opaque filler, and wherein the concentration of the radio-opaque filler is measurably different in each layer is disclosed herein. The radio-opaque filler is preferably a compound based on barium, bismuth, tungsten, iodine, or reduced iron.

A system assesses activity and displays a unitless activity value. A detector senses activity of a user. A processor reads sensed activity data from the detector. A display displays the unitless activity value. An enclosure houses the detector and the processor. The processor periodically reads the sensed activity data from the detector and processes the data to generate an activity number, the number being used to generate the unitless activity value based upon a maximum number and a display range.

Described are methods of estimating a physical property associated with a region of a sports article. The method includes determining a plurality of structural features within the region, determining, for each structural feature, a feature value, mapping each feature value to a physical property, wherein the mapping is based on a machine learning algorithm from a limited plurality of samples, and wherein each sample associates a feature value with a value of the physical property, and using the mapping to estimate the physical property for the region.

A golf ball comprising layers that have from 0.05% to 70% by weight of a radio-opaque filler, and wherein the concentration of the radio-opaque filler is measurably different in each layer is disclosed herein. The radio-opaque filler is preferably a compound based on barium, bismuth, tungsten, iodine, or reduced iron.

A system assesses activity and displays a unitless activity value. A detector senses activity of a user. A processor reads sensed activity data from the detector. A display displays the unitless activity value. An enclosure houses the detector and the processor. The processor periodically reads the sensed activity data from the detector and processes the data to generate an activity number, the number being used to generate the unitless activity value based upon a maximum number and a display range.

A golf ball comprising layers that have from 0.05% to 70% by weight of a radio-opaque filler, and wherein the concentration of the radio-opaque filler is measurably different in each layer is disclosed herein. The radio-opaque filler is preferably a compound based on barium, bismuth, tungsten, iodine, or reduced iron.

A system for measuring rigidity characteristics that measures a CT value of a golf club head based on an acceleration occurring in an impactor when the impactor is caused to strike the golf club head. Correlation data is calculated by measuring a representative CT value of the golf club head, which is calculated based on CT values measured multiple times by changing the impact velocity of the impactor, and a test velocity CT value, which is a CT value when the impact velocity is set to a predetermined test velocity, for each of a plurality of the golf club heads of an identical model. A rigidity characteristic value measuring device measures the test velocity CT value for another golf club head of the model. A computer estimates the representative CT value of the other golf club head based on the test velocity CT value and the correlation data.