Engineering topics

Ruck, G. T.

Publications and source records attributed to Ruck, G. T..

8 records

NASA NTRS1983

An Assessment of Potential Detectors to Monitor the Man-made Orbital Debris Environment

Observations using NORAD radar showed that man made debris exceeds the natural environment for large objects. For short times (a few days to a few weeks) after solid rocket motor (SRM) firings in LEO, man made debris in the microparticle size range also appears to exceed the meteoroid environment. The properties of the debris population between these size regimes is currently unknown as there has been no detector system able to perform the required observations. The alternatives for obtaining data on this currently unobserved segment of the population are assessed.

Reynolds, R. C.↗

NASA NTRS1979

Satellite interferometer as an advanced navigation/communication system

An orthogonal system of interferometry baselines aboard a geostationary satellite is proposed to be used for navigation, surveillance, and traffic control. Position determination is based on the relationship between the measured phase differences, the known and unknown transmitter locations, and other systematic error model parameters using a generalized least-squares estimation procedure. It is shown that position accuracy is critically dependent on the baseline length and on the magnitude of the random component of the measuring errors. Several trade-offs with respect to the system accuracies, the number of users, data rates, hardware costs, etc., are examined. Simultaneous use of the same channels for navigation and data transfer is found feasible and five candidate or 'strawman' interferometer system proposals are presented. It is concluded that the system's performance is excellent in comparison with present or planned systems, and that it is viable in meeting potential user's requirements.

Gopalapillai, G. S.↗

NASA NTRS1977

Applications of a High-Altitude Powered Platform (HAPP)

A list of potential uses for the (HAPP) and conceptual system designs for a small subset of the most promising applications were investigated. The method was to postulate a scenario for each application specifying a user, a set of system requirements and the most likely competitor among conventional aircraft and satellite systems. As part of the study of remote sensing applications, a parametric cost comparison was done between aircraft and HAPPS. For most remote sensing applications, aircraft can supply the same data as HAPPs at substantially lower cost. The critical parameters in determining the relative costs of the two systems are the sensor field of view and the required frequency of the observations being made. The HAPP is only competitive with an airplane when sensors having a very wide field of view are appropriate and when the phenomenon being observed must be viewed at least once per day. This eliminates the majority of remote sensing applications from any further consideration.

Kuhner, M. B.↗

NASA NTRS1976

Feasibility of satellite interferometry for surveillance, navigation, and traffic control

The feasibility of using a satellite borne interferometry system for surveillance, navigation, and traffic control applications was investigated. The evaluation was comprised of: (1) a two part systems analysis (software and hardware); (2) a survey of competitive navigation systems (both experimental and planned); (3) a comparison of their characteristics and capabilities with those of an interferometry system; and (4) a limited survey of potential users to determine the variety of possible applications for the interferometry system and the requirements which it would have to meet. Five candidate or "strawman" interferometry systems for various applications with various capabilities were configured (on a preliminary basis) and were evaluated. It is concluded that interferometry in conjunction with a geostationary satellite has an inherent ability to provide both a means for navigation/position location and communication. It offers a very high potential for meeting a large number of user applications and requirements for navigation and related functions.

Gopalapillai, S.↗

NASA NTRS1975

Bistatic radar sea state monitoring system design

Remote measurement of the two-dimensional surface wave height spectrum of the ocean by the use of bistatic radar techniques was examined. Potential feasibility and experimental verification by field experiment are suggested. The required experimental hardware is defined along with the designing, assembling, and testing of several required experimental hardware components.

Ruck, G. T.↗

NASA NTRS1975

Bistatic radar sea state monitoring field test

Recent advances in understanding the physical phenomena controlling the interaction of electromagnetic energy with the ocean surface have revealed the possiblity of remote measurement of the two-dimensional surface wave height spectrum of the ocean using bistatic radar techniques. The basic feasibility of such a technique operating at frequencies in the HF region (3 to 30 MHz) was examined during previous studies and hardware for an experimental verification experiment was specified. The activities have resulted in a determination of the required hardware and system parameters for both satellite and aircraft systems, the development, assembly, and testing of hardware for an experimental aircraft system, the development and initial testing of data processing procedures, and the conduct of an initial flight test experiment. Activities were devoted to completing the assembly and testing of the experimental hardware, completing the experiment planning, conducting a field test experiment, and the processing and analysis of the experimental data. Even though directional spectrum maps of the test area cannot be generated from the measured data, the hardware concept employed appears viable, and solutions to the problems encountered have been identified.

Ruck, G. T.↗

NASA NTRS1974

Bistatic sea state radar monitoring system and applications to marine geodesy

The bistatic scattering of high frequency radio waves can be used to observe directional ocean-wave spectra. This makes it possible to measure RMS wave heights. An experimental aircraft system for such measurements is discussed. The system utilizes a surface transmitter and an airborne receiver. Questions of high frequency scattering from the ocean surface are considered along with surface spectrum measurements.

Ruck, G. T.↗

NASA NTRS1972

Bistatic radar sea state monitoring

Bistatic radar techniques were examined for remote measurement of the two-dimensional surface wave height spectrum of the ocean. One technique operates at high frequencies (HF), 3-30 MHz, and the other at ultrahigh frequencies (UHF), approximately 1 GHz. Only a preliminary theoretical examination of the UHF technique was performed; however the principle underlying the HF technique was demonstrated experimentally with results indicating that an HF bistatic system using a surface transmitter and an orbital receiver would be capable of measuring the two-dimensional wave height spectrum in the vicinity of the transmitter. An HF bistatic system could also be used with an airborne receiver for ground truth ocean wave spectrum measurements. Preliminary system requirements and hardware configurations are discussed for both an orbital system and an aircraft verification experiment.

Ruck, G. T.↗