Ophir Corporation

Radiometrics Corporation

Loren Dean Nelson

Martin Joseph O'Brien

Carl Scott Weimer

Loren M Caldwell

Randolph H Ware

David C MacPherson

Lee A Erb

Fredrick S Solheim

Paula R Wamsley

Todd A Cerni

Stuart Paul Beaton

Donald Rottner

Systems and methods for sensing air outside a moving aircraft are presented. In one embodiment, a system includes a laser for generating laser energy. The system also includes one or more transceivers for projecting the laser energy as laser radiation to the air. Subsequently, each transceiver receives laser energy as it is backscattered from the air. A computer processes signals from the transceivers to distinguish molecular scattered laser radiation from aerosol scattered laser radiation and determines one or more air parameters based on the scattered laser radiation. Such air parameters may include air speed, air pressure, air temperature and aircraft orientation angle, such as yaw, angle of attack and sideslip.

Optical air data systems and methods

A method optimizes gas correlation radiometer response to trace amounts of target gas in the free atmosphere in competition with interfering gas. Operations identify spectral regions of a first absorption spectrum of the target gas, and of a second absorption spectrum of the interfering gas. A set of similarity data is determined as a function of overlap regions within the spectral region, and a set of contrast data is determined as a function of non-overlap regions within the spectral region, including a plurality of data items within each of a plurality of bandwidths, and a data item corresponding to a center wavelength within each bandwidth. Graphs correspond to each bandwidth. From one graph a center wavelength of an infrared filter is selected, and from another graph there is selected a bandwidth of the infrared filter, to configure an infrared filter for use with the gas correlation radiometer.

Method of optimizing a response of a gas correlation radiometer to a trace amount of a target gas

A source directs broadband modulated light into a region the free atmosphere in which target gas may be present. A gas correlation radiometer responds to light transmitted through the region. Separate radiometer channels respond to a single beam of light after transmission through the region. A beam splitter separates the beam into two beams, one directed into each of the channels. The two channels separately and simultaneously respond to a respective one of the light beams for separately and simultaneously generating signals that together indicate whether the target gas is in the free atmosphere. A method provides an optimal bandpass of an IR filter that filters the light before transmission to the radiometers. Another method uses a null factor in computing an output that determines the concentration of the target gas in the free atmosphere. Long distance detection embodiments may be borne by vehicles such as trucks or aircraft.

Methods of and apparatus for detecting low concentrations of target gases in the free atmosphere

An oil and gas exploration system and method for land and airborne operations, the system and method used for locating subsurface hydrocarbon deposits based upon a remote detection of trace amounts of gases in the atmosphere. The detection of one or more target gases in the atmosphere is used to indicate a possible subsurface oil and gas deposit. By mapping a plurality of gas targets over a selected survey area, the survey area can be analyzed for measurable concentration anomalies. The anomalies are interpreted along with other exploration data to evaluate the value of an underground deposit. The system includes a differential absorption lidar (DIAL) system with a spectroscopic grade laser light and a light detector. The laser light is continuously tunable in a mid-infrared range, 2 to 5 micrometers, for choosing appropriate wavelengths to measure different gases and avoid absorption bands of interference gases. The laser light has sufficient optical energy to measure atmospheric concentrations of a gas over a path as long as a mile and greater. The detection of the gas is based on optical absorption measurements at specific wavelengths in the open atmosphere. Light that is detected using the light detector contains an absorption signature acquired as the light travels through the atmosphere from the laser source and back to the light detector. The absorption signature of each gas is processed and then analyzed to determine if a potential anomaly exists.

Oil and gas exploration system and method for detecting trace amounts of hydrocarbon gases in the atmosphere

An advance in a passive, remote sensing device for measurement of atmospheric temperature utilizes an actuated modulator for periodically alternating the radiation detected by a detector at a selected infrared wavelength between the infrared radiation from the atmosphere and that from the infrared reference radiation emitted from a reference material such that the detector compares the radiation emitted from the atmosphere to that emitted by the reference material at the selected infrared wavelength in order to determine the atmosphere temperature. Preferably, the modulator is a MEMS based modulator having a movable grating formed by MEMS based fabrication techniques.

Method and apparatus for measuring atmospheric temperature

Apparatus performs a method of generating one or more output laser pulses in a range of 2 to 6 microns. When a plurality of the output laser pulses are generated, a first output pulse has any selected wavelength within the range and a second output pulse is temporally closely spaced relative to the first output pulse and has a chosen wavelength differing from the selected wavelength. An oscillator laser cavity is provided with a tunable oscillator rod capable of generating initial laser pulses within a range of from 750 to 1000 nm, and a tuning element is coupled to the rod. A flashlamp is operable to pump the rod. For two pulse operation, the flashlamp has a given duration. A Q-switch provides the initial laser pulses upon operation of the tuning element and the flashlamp. A Raman device coupled to the rod shifts the wavelength of such initial laser pulse into the range of from 2 to 6 microns to form the output laser pulse having a wavelength within the range. For multiple pulses, a controller causes the Q-switch to provide first and second ones of the initial laser pulses, spaced by a time interval less than the given duration. Also, a selector coupled to the tuning element is operable within such duration to successively select the wavelength of the first output pulse and the chosen wavelength of the second initial pulse. The Raman device is responsive to each of the initial light pulses to generate radiation at first and second Stokes wavelengths, each of said the output laser pulses being radiation at the second Stokes wavelength.

Method and apparatus for generating high power laser pulses in the two

Apparatus and methods for profiling atmospheric temperature, water vapor and/or cloud liquid content utilizing passive microwave remote sensing are disclosed. The apparatus includes an antenna for receiving atmospheric microwave emissions having frequencies of interest, a highly stable, tunable frequency synthesizer, and downconverting system receiving selected frequency outputs from the synthesizer and the received emissions and, responsive thereto, providing output signals indicative of the frequencies of interest and representing the profile.

Profiling of selected atmospheric characteristics utilizing passive

Contrail detection aft of an aircraft is provided by a rear-looking ranging system carried by the aircraft. A randomly modulated laser beam is directed into a detection volume aft of the aircraft for scatter back toward a detector on the aircraft. Bistatic mounting of a laser and a telescope of the detector preclude sensing of the scattered beam forward of the detection volume. Processing of the detected scattered beam includes cross correlation and analysis to indicate the formation of the contrail aft of the aircraft.

Rear-looking apparatus and method for detecting contrails

Apparatus and method determine the concentration of an individual component, such as water vapor, of a multi-component mixture, such as a gaseous mixture for cooling a nuclear reactor. A hygrometer apparatus includes an infrared source for producing a broadband infrared energy beam that includes a strong water vapor absorption band and a weak water vapor absorption region. The beam is chopped to select infrared pulses. A temporally first pulse has a wavelength in the weakly absorbing region, a temporally second pulse has a wavelength in the strong band and a temporally third pulse has a wavlength in the weakly absorbing region. A fourth reference pulse representing background radiation is interposed in such chopped pulses. An indium arsenide infrared sensor is responsive to the pulses for generating an output signal in proportion to: ##EQU1## where N1 is proportional to the transmission through the sample of the first signal, N4 is related to the background radiation, and [K2 (N2-N4)+K3 (N3-N4)] is the time-weighted average of the transmission through the sample of the second and third pulses applicable at the time of the second pulse, with the reference pulse N4 being subtracted in each case to render the ratio independent of variations in the background radiation.

Method of and apparatus for measuring vapor density

A passive, multi-channel microwave radiometer includes an antenna-lens assembly for receiving, and a first waveguide designed to provide a common path for propagating, 23.8 GHz and 31.4 GHZ atmospheric signals. The 23.8 GHz signal is above the frequency of relative maximum water vapor absorption and the 31.4 GHz signal is near a relative minimum in the water vapor absorption spectrum. Circuitry is responsive to the atmospheric signals for generating output signals representing the respective water vapor and liquid content in and the temperature of the atmosphere. For realtime calibration a blackbody assembly is mounted in the near field of the antenna-lens assembly. The blackbody assembly emits known blackbody microwave signals at 23.8 GHz, 31.4 GHz and in the V band. The radiometer is calibrated during its normal operation by causing a mirror to select the blackbody signals for propagation along the common path. The circuitry responds to the blackbody signals to represent them as first blackbody reference signals. A factory calibrated noise diode assembly adds a known noisy microwave signal to the first waveguide when a blackbody signal is being processed. The circuitry separately responds to such combined blackbody and noisy signals to separately generate a second blackbody reference signal. These first and second blackbody reference signals and the known temperature of the blackbody assembly are used to provide realtime calibration data that is used in realtime to obtain the output signals in response to the atmospheric signals.

Microwave radiometer and methods for sensing atmospheric moisture and

An apparatus for measuring vapor density and saturation ratio of individual chemical species in multi-component, multi-phase systems includes means to permit measurement in supersaturated vapor and in the presence of liquid, solid and dispersed aerosol phases of the sampled gas component and of other chemical species. Active narrowband differential measurements of broad band radiation passed through the sampled environment and then isolated to a plurality of narrow wavelength bands whose wavelength is related to the gaseous absorption spectra of the sampled species permit the measurement of vapor density of individual chemical components. A concurrent passive radiometric measurement of gas temperature in a strong absorption band of a relatively constant gaseous component enables the conversion of component vapor density to component saturation ratio even in the presence of component or system supersaturation.

Growing community of inventors

Evergreen, CO, United States of America

Loren Dean Nelson