High Crimes and Misdemeanors in Data Analysis
Invited talk going over some of the various data analysis problems that have occurred over the years including the most extreme example of falsifying data.
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Invited talk going over some of the various data analysis problems that have occurred over the years including the most extreme example of falsifying data.
This slide presentation reviews some of the problems of data analysis in analyzing pre and post data. Using as an example, ankle extensor strength (AES) experiments, to measure bone density loss during bed rest, the presentation discusses several questions: (1) How should we describe change? (2) Common analysis methods for comparing post to pre results. (3) What do we mean by "% change"? and (4) What are we testing when we compare % changes?
Required, recommended, and optional features are discussed that benefit preparation and evaluation of the load prediction equations in a strain-gage balance data analysis tool. First, milestones in the evolution of load prediction methods are reviewed so that suggested features can be put into a historical context. Afterwards, independent and dependent variable choices for the balance data analysis are discussed. Then, it is illustrated how three different metrics may be used for the identification of the root cause of an unwanted divergence of the load iterations that may be observed during an iterative load prediction. Finally, a list of features is provided to guide software development efforts.
Topics covered include: a) MTP temperature calibration and data analysis; b) Background for interpreting MTP data; c) Large amplitude temperature structure; d) Gravity waves (GWs) in MTP data; and e) Subsidence over hurricanes.
Progress under this grant has included identifying certain new radio emission components and determining the source location of both these and the two major Uranian radio emission (the SHF and bursty components) by a unique new statistical minimization technique. This new source location technique has subsequently also been applied at Neptune, with considerable success. New radio spectrograms have been prepared to clarify the behavior of such emissions, using both the usual 48-second, log-averaged data and the original 6-second PRA data, the latter showing a number of interesting new features. Also, a plasmasphere was discovered at Uranus, auroral plasma cavities were discovered at both Uranus and Neptune, and it was found that the currently-accepted rotation period for Uranus is in error by a small amount.
Computer program developed as structural-vibration-response data analysis tool for use in dynamic testing of Space Shuttle. Program provides fast and efficient time-domain least-squares curve-fitting procedure for reducing transient response data to obtain structural model frequencies and dampings from free-decay records. Procedure simultaneously identifies frequencies, damping values, and participation factors for noisy multiple-response records.
The objectives of the analysis of the Viking radio tracking data are: (1) the study of Mars, its rotation, topography, and internal structure; (2) the development of a general dynamical model of the solar system; and (3) tests of the fundamental laws of gravitation. The central element in the data analysis is the Planetary Ephemeris Program (PEP) which embodies the mathematical models of the solar system. The asteroid model in PEP is changed to better estimate the mass of a fictitious uniform ring and the masses of eight separate asteroids. A model of the rotation of Mars include a secular rate of change of the period and both annual and semiannual variations in the phase of rotation. Other modifications to this model are discussed.
I will discuss the need for accurate rainfall observations to improve our ability to model the earth's climate and improve short-range weather forecasts. I will give an overview of the recent progress in using of rainfall data provided by TRMM and other microwave instruments in data assimilation to improve global analyses and diagnose state-dependent systematic errors in physical parameterizations. I will outline the current and future research strategies in preparation for the Global Precipitation Mission.
Fundamental explosive testing was conducted by the NASA/MSFC Blast Team (N2L) to determine yields produced from cryogenic liquid mixtures of methane and oxygen for a range of oxygen-to-fuel ratios. The blast wave overpressure and high-speed video data were processed by the NASA led multi-agency data analysis team. This document serves to provide a summary of the optimized data analysis produced and the resulting conclusions regarding the yields achieved during this test program.
Although the STARLINK project was set up to provide image processing facilities to UK astronomers, it has grown over the last 12 years to the extent that it now provides most of the data analysis facilities for UK astronomers. One aspect of the growth of the STARLINK network is that it now has to cater for astronomers working in a diverse range of wavelengths. Since a given individual may be working with data obtained in a variety of wavelengths, it is most convenient if the data can be stored in a common format and the programs that analyze the data have a similar 'look and feel'. What is known as 'STARLINK software' is obtained from many sources: STARLINK funded programmers; astronomers; foreign projects such as AIPS; generally available shareware; and commercial sources when this proves cost effective. This means that the ideal situation of a completely integrated system cannot be realized in practice. Nevertheless, many of the major packages written by STARLINK application programmers and by astronomers do use a common data format, based on the Hierarchical Data System, so that interchange of data between packages designed separately from each other is simply a matter of using the same file names. For example, as astronomer might use KAPPA to read some optical spectra off a FITS tape, then use CCDPACK to debias and flat field the data (it is easy to set up an overnight batch job to do this if there is a lot of data), then use KAPPA to have a quick look at the data and then use Figaro to reduce the spectra. It is useful to divide data analysis packages into wavelength specific packages, or even instrument specific packages, and general purpose ones. Once the instrumental signature has been removed from some data, any appropriate general purpose package can be used to analyze te data. For example, the ASTERIX package deals with x-ray data reduction, but after dealing with all of the x-ray specific processing, an astronomer may well want to find the brightness of objects in a given frame. Since ASTERIX uses the standard STARLINK data format, the astronomer can use PHOTOM or DAOPHOT 2 to measure the brightness of the objects. Although DAOPHOT was written with optical astronomy in mind, it is useful for analyzing data from several wavelengths. The ability of DAOPHOT 2 to handle non-standard point spread functions can be especially useful in many areas of astronomy.
This paper presents an exploration into the development and validation of data analysis approaches for Phasor Measurement Units (PMUs) using open-source datasets and tools. Various methods for event detection, event classification, frequency response, and oscillation analysis were tested. We leverage the capabilities of Archive Walker (AW), the Frequency Response Analysis Tool (FRAT), and the Oscillation Baselining and Analysis Tool (OBAT), all open-source tools, for efficient processing and analysis of synchrophasor data. The open-source Transmission Signature Library (TSL) dataset was employed as a dataset for a comprehensive evaluation to assess the performance and reliability of the proposed methods.
Computer program for component quality control and reliability data analysis
A new multispectral data analysis procedure, based on LARSYS, has been developed which substantially reduces the influence of the analyst. The analysis is automated, including the interpretation of clustering results. The classification results obtained are repeatable and not biased by analyst subjectivity during the analysis.
Standards for Unmanned Aircraft System (UAS) Detect-and-Avoid (DAA) systems are currently being developed under the auspices of the RTCA Special Committee 228 (SC-228). To support the development of these standards, a series of flight tests has been conducted at NASAs Armstrong Flight Research Center (NASA-AFRC). The fourth in this series of flight test activities (Flight Test 4, or simply FT4) was conducted during the Spring and Summer of 2016. FT4 supported the objectives of numerous organizations working toward UAS DAA Minimum Operational Performance Standards (MOPS) and UAS DAA Radar MOPS. The summary provided herein is limited to the objectives, analysis and conclusions of the NASA Ames Research Center (NASA-ARC) SSI team toward the refinement of UAS DAA MOPS. This document provides a high-level overview of FT4 and the SSI-ARC objectives, a summary of the data analysis methodology and recommendations for UAS DAA MOPS refinements based on the data analysis results. A total of 72 encounters were flown to support SSI-ARC objectives. Test results were generally consistent with acceptable UAS DAA system performance and will be considered in broader SC-228 requirements validation efforts. Observed alert lead times indicated acceptable UAS DAA alerting performance. Effective interoperability between the UAS DAA system and the Traffic Alert and Collision Avoidance System (TCAS) was observed with one notable exception: TCAS Resolutions Advisories (RA) were observed in the absence of any DAA alert on two occasions, indicating the need for alert parameter refinement. Findings further indicated the need for continued work in the areas of DAA Well Clear Recovery logic and alert stability for Mode-C-only intruders. Finally, results demonstrated a high level of compliance with a set of evaluation criteria designed to provide anecdotal evidence of acceptable UAS DAA system performance.
Power spectral density (PSD) data for all of the flight points examined during the Phase 2 flight data analysis are presented in tabular form. Detailed descriptions of the aircraft, the flight instrumentation and the analysis techniques are given. Measured and calculated vibration mode frequencies are also presented to assist in further interpretation of the PSD data.
LISA Pathfinder (LPF) is an ESA-launched demonstration mission of key technologies required for the joint NASA-ESA gravitational wave observatory in space, LISA. As part of the LPF interferometry investigations, analytic models of noise sources and corresponding noise subtraction techniques have been developed to correct for effects like the coupling of test mass jitter into displacement readout, and fluctuations of the laser frequency or optical pathlength difference. Ground testing of pre-flight hardware of the Optical Metrology subsystem is currently ongoing at the Albert Einstein Institute Hannover. In collaboration with NASA Goddard Space Flight Center, the LPF mission data analysis tool LTPDA is being used to analyze the data product of these tests. Furthermore, the noise subtraction techniques and in-flight experiment runs for noise characterization are being defined as part of the mission experiment master plan. We will present the data analysis outcome of preflight hardware ground tests and possible noise subtraction strategies for in-flight instrument operations.
The focus of this paper is on the data analysis tools for the Mars Observer Attitude and Articulation Control Subsystem (AACS). Four different categories of analysis tools are presented, with details offered for specific tools. These same tools, and extensions thereof, have been adopted by the Galileo mission operations, and are being designed into Cassini and other future spacecraft mission operations.
Three separate tasks were proposed under this award. The first involved extending our continuing study of electrodynamical feedback between the thermosphere/ionosphere and the magnetosphere. The second was a model-experiment comparison study of global dynamics and the third was a 'spectral energetics' analysis of tidal dissipation and energy exchange mechanisms. The Earth's mesosphere and lower-thermosphere/ionosphere (MLTI), between approximately 60 and 180 km altitude, is the most poorly understood region of the Earth's atmosphere, primarily because of its relative inaccessibility. This lack of knowledge has been widely recognized and has provided important scientific rationale for the upcoming NASA TIMED mission. While the data gathered during the TIMED era will revolutionize our understanding of the MLTI region, much work can be done prior to the mission, both to develop data-analysis and modeling techniques and to study the more limited relevant experimental data from previous missions. The grant reported on here continues and extends an existing successful program of scientific research into the energetics, dynamics and electrodynamics of the MLTI, using available theoretical and data analysis tools.