Abstract: A continuous-wavelength absorption detector adapted for continuous-flow detection is provided. The detector includes an electronics section, a bifurcated optical guide and a detector-cell. Each branch of the optical guide has a plurality of fibers, and at one end the branches are separated and connected to different portions of the electronics section. One of the branches is terminated next to a source for producing illumination to irradiate sample material and the other branch is terminated next to a detector for producing an absorption spectrum signal. At the opposite end of the optical guide the fibers of the two branches are combined to form a common end which is connected to the detector-cell. The detector-cell includes an approximately vertically aligned continuous-flow sample cell which is connected to a sample line and also includes a concave mirror.

Abstract: An apparatus and method for measuring the water level at the bottom of a storage tank, the water level being the product-water interface between product and water within the storage tank. The apparatus includes a sensor assembly which is located at the tank bottom. The assembly has a plurality of measurement sensors arranged in a housing having slots for product and water to enter and leave the housing. Each measurement sensor is an open-circuited co-axial transmission line with a probe at its open end which functions as a monopole antenna. In preferred embodiments, the transmission lines are quarter wavelength open-circuited coaxial transmission lines. Each probe is located at a different distance from the tank bottom to cover a measurement range. The transmission lines are excited with signals which are reflected by the probes.

Abstract: A method is provided to detect leakage from a conduit through which a stream of fluid flows and to indicate when there is a leakage condition or a no leakage condition. The method includes measuring at least one variable of a group consisting of fluid pressure and fluid flow rate over a period of time and at least one location of the stream to provide a data set representing the variable at the location and over the period of time. A statistical probability of obtaining the data set from the measurement under a first hypothesis that no leakage occurs is determined and a statistical probability of obtaining the data set from the measurement under a second hypothesis that leakage occurs is determined. One of the hypotheses is selected as being true if the probability of obtaining the data set from the measurement under the selected hypothesis is larger than the probability of obtaining the data set from the measurement under the other hypothesis.

Abstract: A remote sensing system is provided which operates as a bipolarized, differential mode, LDI (laser differential interferometry) system to detect an electrical signal produced at a remote location. The system is adapted to reduce the effects of turbulence induced frequency fluctuations by using an array retroreflector apparatus which converts a single sensing beam into a single return beam having two, overlapping, transversely polarized sensing signals; thus, turbulence induced noise will be common mode to both return signals and cancel at the receiver.In preferred embodiments, the system is used to remotely detect an amplified array signal from a plurality of seismic detectors (e.g., geophones or hydrophones) connected to form an array at the remote location. The target is coupled to common motions at the selected location and the amplified array signal is coupled to an optical component within the target.

Abstract: A multi-mode receiver sonde having individual receiver stations. The receiver stations have transducers which have a flat frequency response over a selected bandwidth so that there is an approximately constant ratio in amplitude and substantially little phase difference between the response signal and an input acoustic signal from a liquid containing borehole.The wide-band output response signals are combined to form composite signals which represent selected borehole propagation modes. Accurate comparisons can then be made between the composite signals obtained by separate receiver stations so that changes in phase and amplitude over distance and time can be determined.In one highly preferred embodiment, the receiver sonde has a semi-rigid receiver array. The semi-rigid receiver array is adapted to decouple noise (tool-mode noise and/or road-noise) in one location within the array from other locations within the array by using compliant spacers between the receiver stations to absorb and scatter the noise.

Abstract: A remote sensing system is provided which operates as a bipolarized, differential mode, LDI (laser differential interferometry) system to detect motion at a remote location. The system is adapted to reduce the effects of turbulence induced frequency fluctuations by using a retroreflector apparatus which converts a single sensing beam into a single return beam having two overlapping transversely polarized sensing signals; thus, turbulence induced noise will be common mode to both return signals and cancel at the receiver. In preferred embodiments, the system is used to detect seismic motions. The retroreflector apparatus is coupled to ground motions at a selected location where it separates the sensing beam into two polarized sensing signals, frequency modulates one of the polarized sensing signals to contain frequency components that represent selected ground motions, and combines the polarized sensing signals into the return beam. The return beam is detected.

Abstract: A marine cable retrieval apparatus for retrieving marine seismic cable on board a ship which reduces longitudinal tension force on the cable at the cable storage reel when the cable storage reel (drum) is winding up the cable. Marine cable is subject to a tension force which can damage the marine cable when it is placed on a storage reel. The apparatus of this application reduces the tension on a portion of marine cable so that the portion can be retrieved upon a storage reel. The apparatus includes a collar attached to the marine cable and a cable retrievel tool which is placed around the marine cable. The cable retrieval tool has a biasing mechanism which will allow the tool to pass over the collar attached to the marine cable when it is moving away from the ship, but when it is moving toward the ship the biasing mechanism will engage the collar. The cable retrieval tool exerts an opposing force on the collar to the longitudinal tension force on marine cable trailing behind the collar.

Abstract: A method is provided for adaptive minimum-phase deconvolution. The deconvolution method removes source and receiver wavelet variations in a surface-consistent manner from traces of a seismic survey which has the traces indexed by source and receiver locations. A plurality of source-pairs and a plurality of a receiver-pairs are selected from the traces. Each source-pair has two designated sources and each receiver-pair has two designated receivers. Cross-correlations are performed on traces in each source-pair which have common receivers to provide a source-pair cross-correlation signal for each common receiver. Cross-correlation are performed on traces in each receiver-pair which have common sources to provide a receiver-pair cross-correlation signal for each common source. The cross-correlation signals of each receiver-pair and each source-pair are stacked to provide stacked cross-correlation signals.

Abstract: A method to adjust a common subsurface feature on seismic traces associated with line misties is provided so that the seismic traces are consistent about the common subsurface feature. The method uses traces which are uniquely located in an x-y coordinate system to reflect the actual location of the traces with respect to an intersection. In this method traces can be associated with a line of seismic data or can be isolated traces such as well-log synthetics or vertical seismic profiles. The traces make up sets of data. An intersection is selected and representative traces from two sets of data are initially selected and form trace pairs. A time gate is determined about a common subsurface features of interest on the representative traces. The time gate isolates a trace gate about the common subsurface feature on each trace leaving only the trace gates in the trace pairs. A time delay is determined for each trace pair.