Surface Profilometry

As outlined in the previous chapter, existing technologies for surface profilometry show certain drawbacks in terms of resolution, dynamic measurement range, three-dimensional measurement capabilities and speed. The following chapter introduces a novel approach to surface profilometry which aims to provide solutions to the problems named. The basic setup for all experiments is centered around a two-beam interferometer of the Michelson type.

Metrological framework to support accurate, reliable, and reproducible nucleic acid measurements

Nucleic acid analysis is used in many areas of life sciences such as medicine, food safety, and environmental monitoring. Accurate, reliable measurements of nucleic acids are crucial for maximum impact, yet users are often unaware of the global metrological infrastructure that exists to support these measurements. In this work, we describe international efforts to improve nucleic acid analysis, with a focus on the Nucleic Acid Analysis Working Group (NAWG) of the Consultative Committee for Amount of Substance: Metrology in Chemistry and Biology (CCQM). The NAWG is an international group dedicated to improving the global comparability of nucleic acid measurements; its primary focus is to support the development and maintenance of measurement capabilities and the dissemination of measurement services from its members: the National Metrology Institutes (NMIs) and Designated Institutes (DIs). These NMIs and DIs provide DNA and RNA measurement services developed in response to the needs of their stakeholders. The NAWG members have conducted cutting edge work over the last 20 years, demonstrating the ability to support the reliability, comparability, and traceability of nucleic acid measurement results in a variety of sectors.

Instrumented Wave Gliders for Air-Sea Interaction and Upper Ocean Research

Over the last several years, the Air-Sea Interaction Laboratory at Scripps Institution of Oceanography has developed a fleet of wave-powered, uncrewed Wave Gliders (Liquid Robotics) specifically designed and instrumented for state-of-the-art air-sea interaction and upper ocean observations. In this study, measurement capabilities from these platforms are carefully described, compared, and validated against coincident measurements from well-established, independent data sources. Data collected from four major field programs from 2013 to 2020 are considered in the analysis. Case studies focusing on air-sea interaction, Langmuir circulations, and frontal processes are presented. We demonstrate here that these novel, instrumented platforms are capable of collecting observations with minimal flow-structure interaction in the air-sea boundary layer, a region of crucial current and future importance for models of weather and climate.

Problems of the measurement management systems evaluation for business entities on voluntary basis

Questions concerning evaluation and confirmation of measurement capabilities for business entities on a voluntary basis are considered. Existing problems in executing this kind of activity by enterprises, which are regulated by the Ministry of Economy of Ukraine (metrological centers) as well as other enterprises and organizations. Causes of impossibility to issue certificates on compliance of the measurement management systems with requirements of DSTU ISO 10012 as a result of providing the above-mentioned operations are determined. The ways of solving the determined questions for metrological centers are proposed.

Comparison of Submillinewton Thrust Measurements Between a Laser Interferometer and a Load Cell on a Pendulum Balance

Reliable measurements of thrust from systems to be flown on satellites are essential to ensure repeatable maneuvering capability of small nanosatellites. Thrusters can be used to vary spacecraft orientation, detumbling, and orbit change. Tests have been conducted in a low-pressure vacuum system using a cold gas prototype thruster and two independently calibrated methods: a four-point pendulum with a laser interferometer displacement sensor and a load cell, both of which have measurement capabilities from tens of micronewtons to tens of millinewtons. The agreement is very good, lending confidence in both methods. The advantages and disadvantages of both methods will be discussed. They include absolute accuracy, low thrust accuracy, temporal resolution, simplicity of operation, cost, and sensitivity to vibrations generated by laboratory equipment such as pumps, fans, bumps, and human movement.

EXPRESS: Design Considerations for Discrete Frequency Infrared Microscopy Systems

Discrete frequency infrared (DFIR) chemical imaging is transforming the practice of microspectroscopy by enabling a diversity of instrumentation and new measurement capabilities. While a variety of hardware implementations have been realized, considerations in the design of all-IR microscopes have not yet been compiled. Here we describe the evolution of IR microscopes, provide rationales for design choices, and the major considerations for each optical component that together comprise an imaging system. We analyze design choices in illustrative examples that use these components to optimize performance, under their particular constraints. We then summarize a framework to assess the factors that determine an instrument’s performance mathematically. Finally, we summarize the design and analysis approach by enumerating performance figures of merit for spectroscopic imaging data that can be used to evaluate the capabilities of imaging systems or suitability for specific intended applications. Together, the presented concepts and examples should aid in understanding available instrument configurations, while guiding innovations in design of the next generation of IR chemical imaging spectrometers.

Development of a Compound Speckle Interferometer for Precision Three-Degree-of-Freedom Displacement Measurement

In this study, a compound speckle interferometer for measuring three-degree-of-freedom (3-DOF) displacement is proposed. The system, which combines heterodyne interferometry, speckle interferometry and beam splitting techniques, can perform precision 3-DOF displacement measurements, while still having the advantages of high resolution and a relatively simple configuration. The incorporation of speckle interferometry allows for non-contact displacement measurements by detecting the phase of the speckle interference pattern formed from the convergence of laser beams on the measured rough surface. Experiments were conducted to verify the measurement capabilities of the system, and the results show that the proposed system has excellent measurement capabilities suitable for future real-world applications.

The electrodynamic influence of thermospheric winds in the daytime ionosphere.

<p>The electrodynamic influence of thermospheric winds is an effect thought to dominate the development of<span> </span>the daytime low-latitude ionosphere, through the generation of dynamo currents and associated vertical plasma drifts. Until recently, observations of the thermospheric and ionopsheric state variables have mainly been defined and compared on climatological time scales, due to their collection from separate observatories with disparate measurement capabilities.<span>  </span>These datasets are inadequate for investigation of the actual action of thermospheric drivers as they modify the ionospheric state, as the response clearly changes on 24-hour timescales, and shorter when viewed in the a constant-local-time frame<span> </span>of reference. New observatiions of thermospheric winds, uninterrupted over the 90-300 km altitude range, are now provided by the Ionospheric Connection Explorer along with simultaneous plasma velocity and density measurments. These observations are directly comparable to the wind measurements in crossings of the magnetic equator, where the winds are magnetically conjugate to the drift measurements. Investigation of the noon-sector drifts vs wind drivers is presented. We find that the local driver is clearly evident in the noon-time vertical plasma drifts under all conditions.</p><p> </p>