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Vanzandt, Thomas R.

Publications and source records attributed to Vanzandt, Thomas R..

Capacitive Position Sensor For Accelerometer

Capacitive position sensor measures displacement of proof mass in prototype accelerometer described in "Single-Crystal Springs for Accelerometers" (NPO-18795). Sensor is ultrasensitive, miniature device operating at ultra-high frequency and described in more detail in "Ultra-High-Frequency Capacitive Displacement Sensor," (NPO-18675). Advances in design and fabrication of prototype accelerometer also applicable to magnetometers and other sensors in which sensed quantities measured in terms of deflections of small springs.

Vanzandt, Thomas R.

Single-Crystal Springs For Accelerometers

Thermal noise reduced, enabling use of smaller proof masses. Spring-and-mass accelerometers in which springs made of single-crystal material being developed. In spring-and-mass accelerometer, proof mass attached to one end of spring, and acceleration of object at other end of spring measured in terms of deflection of spring, provided frequency spectrum of acceleration lies well below resonant frequency of spring-and-proof-mass system. Use of single-crystal spring materials instead of such polycrystalline spring materials as ordinary metals makes possible to construct highly sensitive accelerometers (including seismometers) with small proof masses.

Vanzandt, Thomas R.

Ultra-High-Frequency Capacitive Displacement Sensor

Improved class of compact, high-resolution capacitive displacement sensors operates at excitation frequency of 915 MHz and measures about 7.5 by 4 by 2 centimeters. Contains commercially available 915-MHz oscillator and transmission-line resonator. Resonator contains stripline inductor in addition to variable capacitor. Ultrahigh excitation frequency offers advantages of resolution and frequency response. Not deleteriously affected by mechanical overdriving, or contact between electrodes.

Vanzandt, Thomas R.

Micro-sensors for in-situ meteorological measurements

Improved in-situ meteorological measurements are needed for monitoring the weather and climate of the terrestrial and Martian atmospheres. We have initiated a program to assess the feasibility and utility of micro-sensors for precise in-situ meteorological measurements in these environments. Sensors are being developed for measuring pressure, temperature, wind velocity, humidity, and aerosol amounts. Silicon micro-machining and large scale integration technologies are being used to make sensors that are small, rugged, lightweight, and require very little power. Our long-term goal is to develop very accurate miniaturized sensors that can be incorporated into complete instrument packages or 'micro weather stations,' and deployed on a variety of platforms. If conventional commercially available silicon production techniques can be used to fabricate these sensor packages, it will eventually be possible to mass-produce them at low cost. For studies of the Earth's troposphere and stratosphere, they could be deployed on aircraft, dropsondes, radiosondes, or autonomous surface stations at remote sites. Improved sensor accuracy and reduced sensor cost are the primary challenges for these applications. For studies of the Martian atmosphere, these sensor packages could be incorporated into the small entry probes and surface landers that are being planned for the Mars Environmental SURvey (MESUR) Mission. That decade-long program will deploy a global network of small stations on the Martian surface for monitoring meteorological and geological processes. Low mass, low power, durability, large dynamic range and calibration stability are the principal challenges for this application. Our progress on each of these sensor types is presented.

Crisp, David

Micro-Sensors for in-situ Meteorological Measurements

Improved in-situ meteorological measurements are needed for monitoring the weather and climate of the terrestrial and martian atmospheres. We have initiated a program to assess the feasibility and utility of micro-sensors for precise in-situ meteorological measurements in these environments. Sensors are being developed for measuring pressure, temperature, wind velocity, humidity, and aerosol amounts.

Micro-Sensors