Frequency domain laser velocimeter signal processor

A new scheme for processing signals from laser velocimeter systems is described. The technique utilizes the capabilities of advanced digital electronics to yield a signal processor capable of operating in the frequency domain maximizing the information obtainable from each signal burst. This allows a sophisticated approach to signal detection and processing, with a more accurate measurement of the chirp frequency resulting in an eight-fold increase in measurable signals over the present high-speed burst counter technology. Further, the required signal-to-noise ratio is reduced by a factor of 32, allowing measurements within boundary layers of wind tunnel models. Measurement accuracy is also increased up to a factor of five

Mars' Atmosphere: Comparison of Entry Profiles with Numerical Models

This presentation was part of the session : Poster SessionsSixth International Planetary Probe WorkshopAs planetary probes enter an atmosphere, they capture measurements which provide thermodynamic information about the atmosphere, but only within a narrow vertical column within that atmosphere over a limited extent of time. In order to place this in situ information into context, it needs to be correlated with other less spatially resolved but more temporally extensive measurements, which can be provided by orbiters as well as numerical models. Before the entry probe is designed and developed, there needs to be some foreknowledge of conditions the probe will experience. Data from previous probes and orbiters can help, and models can aid by permitting investigation of conditions the orbiters may not have observed. Focusing on Mars, there are now six entry profiles available for analysis and interpretation, as well as a decade's worth of remotely sensed atmospheric thermal and aerosol characterization from orbiting platforms. Additionally, there are one-dimensional (vertical) and three-dimensional numerical models of the atmosphere available to provide predictions for entry probes [1,2,3] (and aerobraking spacecraft [4]) and to aid in interpretations of entry probe measurements. This presentation focuses upon the atmospheric variability that can be experienced by a probe, which has a dependency on atmospheric dust load, season, location (latitude and longitude), and "weather" (baroclinic waves, thermal tides, dust storms, etc.) The primary tool is a numerical model of the Martian atmosphere with significant heritage (NASA AMES GCM), with additional comparison to a new model in development with collaboration with the University of Michigan. Haberle, R. M., J.R. Barnes, J.R. Murphy, M. M Joshi, and J. Schaeffer, Meteorological Predictions for the Mars Pathfinder Lander. J. Geophys. Res., 102, 13301-13311, 1997. Tyler Jr., D., J.R. Barnes, E.D. Skyllingstad, Mesoscale and LES Model Studies of the Martian Atmosphere in Support of Phoenix, Submitted, J. Geophys. Res., Spring 2008. Michaels, T. I., and S.C.R. Rafkin, (2008), Meteorological Predictions for Candidate 2007 Phoenix Mars Lander Sites using MRAMS, Submitted, J. Geophys. Res., Spring 2008. Bougher, S.W., J.R. Murphy, J.M. Bell, R.W. Zurek, Prediction of the Structure of the Martian Upper Atmosphere for the Mars Reconnaissance Orbiter (MRO) Mission, Mars, 2, 10-20, 2006.NASA ; New Mexico Space Grant Fellowship ; NSF Atmospheres Program ; International Planetary Probe Worksho

Understanding Community Needs and Desires

This panel exchange is focused on the Integration Test phase within the development lifecycle with special emphasis and dedicated discussion on integration and testing of complex systems. Layout and scheduling of integration tasks come from the verification of interface and performance requirements. However, planning for integration activities of complex systems is inherently different from traditional systems engineering integration planning activities. Decisions about the systems under development have to consider not only the technical and programmatic viewpoints but also the political, societal, operational, and economic viewpoints. Definition of performance measures, found intrinsic in the plan, with trans-disciplinary implications will be discussed. A scenario of integration of UAS in the NAS will be used as a benchmark of current views and lifecycle challenges

Dust-dynamic feedbacks in the Martian atmosphere: Surface dust lifting

Numerical models have been developed to study surface dust lifting in the Martian atmosphere. The present model is comprised of interactively coupled 3-D dynamical and aerosol transport/microphysical models. The nature of possible feedbacks between surface dust lifting and the amplification/damping of near-surface wind and thermal fields and their implications for additional lifting is investigated. These studies have examined large scale Martian topography for its impact upon the ability of the atmospheric circulation to lift dust from the surface, and the particular component(s) responsible for the lifting (e.g. overturning circulation, thermal tides, baroclinic waves). Analogous experiments in which the lifted dust is radiatively inactive (passive tracer) have been conducted to act as a control against which feedbacks are defined

User Centered, Application Independent Visualization of National Airspace Data

This paper describes an application independent software tool, IV4D, built to visualize animated and still 3D National Airspace System (NAS) data specifically for aeronautics engineers who research aggregate, as well as single, flight efficiencies and behavior. IV4D was origin ally developed in a joint effort between the National Aeronautics and Space Administration (NASA) and the Air Force Research Laboratory (A FRL) to support the visualization of air traffic data from the Airspa ce Concept Evaluation System (ACES) simulation program. The three mai n challenges tackled by IV4D developers were: 1) determining how to d istill multiple NASA data formats into a few minimal dataset types; 2 ) creating an environment, consisting of a user interface, heuristic algorithms, and retained metadata, that facilitates easy setup and fa st visualization; and 3) maximizing the user?s ability to utilize the extended range of visualization available with AFRL?s existing 3D te chnologies. IV4D is currently being used by air traffic management re searchers at NASA?s Ames and Langley Research Centers to support data visualizations

Revisiting logistical friendliness: perspectives of international freight forwarders

Logistical friendliness (unfriendliness) refers to the ease (difficulty) of arranging international freight operations to/from a particular country. The present paper builds upon previous research by 1) examininglogistical friendliness and unfriendliness as two different constructs (rather than as opposite ends of the same continuum), and 2) linking the delineation of logistically friendly and unfriendly countries with the reasons for friendliness (unfriendliness). The study results could be quite valuable with corporate decisions as to which countries to do business in, as well as with the appropriate organizational strategies for entering the chosen countries

Student Perceptions of WebCT in a Web-Supported Instructional Environment: Distance Education Technologies for the Classroom

Web-supported instruction is becoming more commonplace in today\u27s colleges and universities (Lindner, Dooley, & Murphy, 2001). This paper explores student perceptions of the use of WebCT to support instructional objectives in a Web-supported environment. Data for the study were collected with a survey instrument using WebCT on-line testing tools. The results show WebCT contributed to students\u27 ability to accomplish the course objectives. Students, however, continued to rely on print-based course materials and did not create student-centered on-line learning environments

Examining international freight forwarder services: the perspectives of current providers and users

The service quality literature indicates a variety of gaps between expected and perceived quality, and that service quality is a key determinant of customer satisfaction. As such, the present paper examines international freight forwarders (IFFs) and IFF customers with respect to various services which might be provided by IFFs; the paper also reports on user satisfaction with their IFFs. The study results identified several mismatches between what the forwarders are currently providing and what services the users view as important. In addition, the satisfaction ratings suggest that forwarders’ performance has room for improvement

Some propositions regarding rail-truck intermodal: an empirical analysis

Using data compiled from a recent of businesses located in a major metropolitan area, the present paper evaluates a series of propositions concerning rail-truck intermodal. In general, the study results tend to support the various propositions, and key findings suggest that users and nonusers of intermodal transportation have different perceptions about the quality of, and barriers to, intermodal service