Physical Sciences

Twin Head Efficient Oscillator Development for the ACE Multi- Beam Lidar and 3D-Winds

This technology is applicable to atmospheric lidar, Doppler wind measurements, interplanetary laser communications, and materials processing. The Twin Head Efficient Oscillator (THEO) concept uses a pair of smaller, identical laser pump modules, oriented to remove asymmetrical thermo-optical effects typical in single-slab lasers such as HOMER (High Output Maximum Efficiency Resonator), MLA (Mercury Laser Altimeter), LOLA Lunar Orbiter Laser Altimeter, and GLAS (Geoscience Laser Altimeter), while simultaneously increasing efficiency and lifetime. This creates 100+ mJ pulses in an oscillator-only design, with reduced risk of optical damage, record efficiency, high stability, long life, and high TEM00 beam quality typical of much smaller rod-based cavities. Near-field-beam quality is critical to efficient second harmonic generation (SHG 532 nm), which is typically poor in slab-based Nd:YAG lasers.

Posted in: Briefs, TSP, Photonics, Physical Sciences, Altimeters, Spacecraft


Planetary Polarization Nephelometer

Instrument provides more detailed information on aerosols encountered in a planetary environment. Aerosols in planetary atmospheres have a significant impact on the energy balance of the planets, yet are often poorly characterized. An in situ instrument was developed that would provide more diagnostic information on the nature of aerosols it encountered if deployed on a planetary descent probe. Previous probe instruments only measured intensity phase functions, but much particle ambiguity remains with only this information. Adding the polarization phase function greatly reduces particle characteristic ambiguities, but also adds more challenges in designing a measurement approach. Laboratory instrumentation to measure intensity and polarization phase functions have existed since the early 1970s, but these instruments employed quarter-wave plates and Pockels cells to modulate the illuminating beam and the scattered light to isolate the intensity and polarization phase functions. Both of these components are unstable except under tightly controlled thermal conditions. This solution avoids the use of thermally sensitive components such as quarter- wave plates or Pockels cells, and avoids requiring the detectors to be placed around the sensing volume.

Posted in: Briefs, TSP, Photonics, Physical Sciences, Diagnostics, Test equipment and instrumentation


Optical Tunable-Based Transmitter for Multiple High-Frequency Bands

Applications include satellite communications, optical communications networks, and RF antenna applications. The purpose of this innovation is to be able to deliver, individually or simultaneously, multiple microwave high-frequency bands including, but not limited to, L (1.5 GHz), C (7 GHz), X (8.4 GHz), Ku (14.5 GHz), Ka (32 GHz), and Q (38 GHz) frequencies at high data rates and with minimal hardware, particularly for use in satellite-to-satellite communications applications. Additionally, this innovation would be a satellite-based transmitter with a significant reduction in weight, mass, and power when compared to current, conventional technologies.

Posted in: Briefs, Photonics, Physical Sciences, Antennas, Satellite communications


Scatter-Reducing Sounding Filtration Using a Genetic Algorithm and Mean Monthly Standard Deviation

Retrieval algorithms like that used by the Orbiting Carbon Observatory (OCO)-2 mission generate massive quantities of data of varying quality and reliability. A computationally efficient, simple method of labeling problematic datapoints or predicting soundings that will fail is required for basic operation, given that only 6% of the retrieved data may be operationally processed. This method automatically obtains a filter designed to reduce scatter based on a small number of input features.

Posted in: Briefs, TSP, Physical Sciences, Software, Mathematical models, Data acquisition and handling


GPS Estimates of Integrated Precipitable Water Aid Weather Forecasters

This technique improves weather-forecasting operations. Global Positioning System (GPS) meteorology provides enhanced density, low-latency (30-min resolution), integrated precipitable water (IPW) estimates to NOAA NWS (National Oceanic and Atmospheric Administration National Weather Service) Weather Forecast Offices (WFOs) to provide improved model and satellite data verification capability and more accurate forecasts of extreme weather such as flooding. An early activity of this project was to increase the number of stations contributing to the NOAA Earth System Research Laboratory (ESRL) GPS meteorology observing network in Southern California by about 27 stations. Following this, the Los Angeles/Oxnard and San Diego WFOs began using the enhanced GPS-based IPW measurements provided by ESRL in the 2012 and 2013 monsoon seasons. Forecasters found GPS IPW to be an effective tool in evaluating model performance, and in monitoring monsoon development between weather model runs for improved flood forecasting.

Posted in: Briefs, TSP, Physical Sciences, Data Acquisition, Global positioning systems, Global positioning systems (GPS), Water, Weather and climate, Satellites


Cryogenic Liquid Sample Acquisition System for Remote Space Applications

There is a need to acquire autonomously cryogenic hydrocarbon liquid sample from remote planetary locations such as the lakes of Titan for instruments such as mass spectrometers. There are several problems that had to be solved relative to collecting the right amount of cryogenic liquid sample into a warmer spacecraft, such as not allowing the sample to boil off or fractionate too early; controlling the intermediate and final pressures within carefully designed volumes; designing for various particulates and viscosities; designing to thermal, mass, and power-limited spacecraft interfaces; and reducing risk. Prior art inlets for similar instruments in spaceflight were designed primarily for atmospheric gas sampling and are not useful for this front-end application.

Posted in: Briefs, TSP, Physical Sciences, Data Acquisition, Hydrocarbons, Test equipment and instrumentation, Test procedures, Spacecraft


Integrating a Microwave Radiometer into Radar Hardware for Simultaneous Data Collection Between the Instruments

Electronics are shared between the instruments. The conventional method for integrating a radiometer into radar hardware is to share the RF front end between the instruments, and to have separate IF receivers that take data at separate times. Alternatively, the radar and radiometer could share the antenna through the use of a diplexer, but have completely independent receivers. This novel method shares the radar’s RF electronics and digital receiver with t he radiometer, while allowing for simultaneous operation of the ra da r and radiometer.

Posted in: Briefs, TSP, Physical Sciences, Data Acquisition, Antennas, Data acquisition and handling, Radar, Radio equipment


The U.S. Government does not endorse any commercial product, process, or activity identified on this web site.