Abstract: A multispectral selective reflection Lidar system generates alternating pulses of at least two wavelengths and senses returns for determining the presence of a predetermined material absorbing and reradiating one wavelength as selective reflections, but not the other. A detector can readily determine the presence or absence or an absorbing and reradiating return. The system is for preferred use as an orbiter sensor about a planetary body, such as a Jupiter moon, for determining the presence of organic material and for the relay of information back to earth.

Abstract: A multispectral selective reflection Lidar system generates alternating pulses of at least two wavelengths and senses returns for determining the presence of a predetermined material absorbing and reradiating one wavelength as selective reflections, but not the other. A detector can readily determine the presence or absence or an absorbing and reradiating return. The system is for preferred use as an orbiter sensor about a planetary body, such as a Jupiter moon, for determining the presence of organic material and for the relay of information back to earth.

Abstract: A high altitude lidar system propagates a beam of laser pulses through clearings in a cloud formation which reflects off the surface of the earth thereby providing first earth surface returns and reflections towards the base of a cloud that again reflects the pulses back towards the earth surface to be reflected again to provide cloud base returns. The time differential between the earth surface returns and the cloud base returns are used to determine the altitude of the base of the cloud.

Abstract: The present system and method employs Differential Absorption Lidar (DIAL) system and method to measure gas concentration within a plume, for example, ozone density with a rocket exhaust plume when large quantities of chlorine and alumina particles are injected directly into the stratosphere by the current fleet of launch vehicles, the system generate on-resonance and off-resonance pulses prior to plume formation for measuring beyond-plume ambient return and on-resonance and off-resonance pulse during plume formation for measuring beyond-plume returns which are normalized to the ambient returns and then ratioed to indicate the absorption effect within-plume to indicate changes in gas concentrations, being well suited for analysis of environmental affect of the exhaust plumes upon the atmosphere, and particularly, for remote sensing of ozone density within the plume of Titan IV launch vehicles, but can be extended to measure other gas concentration from other types of exhaust plumes.

Abstract: A lidar sensing apparatus having a laser generating alternating pulses at two respective wavelengths, 372 nm and 374 nm, an optical beam transmitter, a receiver telescope for collecting backscattered returns, a band pass optical filter for isolating the returns at 372 nm and 374 nm wavelengths, a photodetector for converting the returns into electronic counts and a data processor for relating the electronic counts into temperature, is used for mesospheric temperature sensing of the iron layer in the 80 to 100 Km altitude regions by collecting fluorescence returns which are related to temperature using a Fe Boltzmann technique. The apparatus also captures backscattered returns from the middle atmosphere between 30 and 80 km for temperature sensing using the Rayleigh technique, providing a complete temperature profile from 30 to 100 km altitudes.

Abstract: Two new passive atomic filters that operate at 422.67 nm and 460.73 nm respectively are disclosed. The filter wavelengths overlap Fraunhofer lines, thereby providing outstanding sunlight rejection. The new calcium filter utilizes collisional energy transfer with Xenon to wavelength shift the violet light to 657.28 nm. An internal photon conversion efficiency of 25% was recorded. The new strontium filter utilizes collisions with noble gases to produce emission at 689.26 nm. An internal photon conversion efficiency of 45% was recorded.

Abstract: An optical atomic resonance filter using a pump laser, a buffer gas and calcium as an atomic vapor converts signals at the g Fraunhofer wavelength (422.674 nm) to UV light which is readily detectable by high sensitivity, large area, low noise, conventional photomultiplier tubes.

Abstract: An optical atomic resonance filter using two pump lasers, a buffer gas and magnesium as an atomic vapor converts underwater signals in the Fraunhofer wavelengths in the green portion of the spectrum to UV light which is readily detectable by conventional photomultiplier tubes.

Abstract: A multiple site laser excited pollution monitoring system having a single laser located at a central location capable of providing a laser output beam, deflected in timed sequence, in a plurality of distinct different directions. Transmitting means, preferably in the form of a plurality of optical fibers, transmit the laser output beam in timed sequence to a plurality of remotely located laser excited pollution detectors (photoacoustic detector heads). Signals from the pollution detectors are transmitted to a signal processor and display unit also located at the central location. As a consequence thereof, a single laser can provide power for a plurality of laser excited detectors at a multiplicity of remote sites and thereby greatly reduce the expense involved in detecting the presence of pollutants at each of the plurality remote locations.

Abstract: An arrangement for detecting low concentrations of atoms. A gaseous sample containing the atoms to be detected is provided and the atoms have a plurality of energy levels with photon inducible transitions between a first energy level and a second level and collision inducible transitions between the second energy level and a third energy level. The atoms undergo spontaneous energy emitting transitions from the third energy level to either the first energy level or to a fourth energy level which is collision coupled to the first energy level. A beam of photons which may be generated, for example, by a laser, having photons with a wave length corresponding to the wave length separation between the first energy level and the second level is provided to irradiate the gaseous sample. A buffer gas is provided in order to collide with the atoms at the second energy level thereby inducing transitions to the third energy level.