The estimation of pointing angle and normalized surface scattering cross section from GEOS-3 radar altimeter measurements

The statistical error of the pointing angle estimation technique is determined as a function of the effective receiver signal to noise ratio. Other sources of error are addressed and evaluated with inadequate calibration being of major concern. The impact of pointing error on the computation of normalized surface scattering cross section (sigma) from radar and the waveform attitude induced altitude bias is considered and quantitative results are presented. Pointing angle and sigma processing algorithms are presented along with some initial data. The intensive mode clean vs. clutter AGC calibration problem is analytically resolved. The use clutter AGC data in the intensive mode is confirmed as the correct calibration set for the sigma computations

In-flight total forces, moments and static aeroelastic characteristics of an oblique-wing research airplane

A low-speed flight investigation has provided total force and moment coefficients and aeroelastic effects for the AD-1 oblique-wing research airplane. The results were interpreted and compared with predictions that were based on wind tunnel data. An assessment has been made of the aeroelastic wing bending design criteria. Lateral-directional trim requirements caused by asymmetry were determined. At angles of attack near stall, flow visualization indicated viscous flow separation and spanwise vortex flow. These effects were also apparent in the force and moment data

Flight characteristics of the AD-1 oblique-wing research aircraft

The AD-1 is a low-speed oblique-wing research airplane. This report reviews the vehicle's basic flight characteristics, including many aerodynamic, stability, and control effects that are unique to an oblique-wing configuration. These effects include the change in sideforce with angle of attack, moment changes with angle of attack and load factor, initial stall on the trailing wing, and inertial coupling caused by a roll-pitch cross product of inertia. An assessment of the handling qualities includes pilot ratings and comments. Ratings were generally satisfactory through 30 deg of wing sweep but degraded with increased sweep. A piloted simulation study indicated that a basic rate feedback control system could be used to improve the handling qualities at higher wing sweeps

Flight-determined aerodynamic derivatives of the AD-1 oblique-wing research airplane

The AD-1 is a variable-sweep oblique-wing research airplane that exhibits unconventional stability and control characteristics. In this report, flight-determined and predicted stability and control derivatives for the AD-1 airplane are compared. The predictions are based on both wind tunnel and computational results. A final best estimate of derivatives is presented

Neutron scattering from some light: heavy rare earth alloys

Neutron scattering and susceptibility measurements as a function of temperature are reported on alloys between the light rare earths Pr and Nd and the heavy rare earths Tb, Dy and Ho over the entire composition range. It is clear from the results that the alloys form three distinct crystallographic and magnetic phases dependent upon composition. The heavy rare earth rich alloys remain in the h.c.p. phase like the parent heavy rare earth metal and the magnetic properties are essentially those of a magnetic dilution system. The ordering temperatures are shown to follow a 2/3 power law with reduced deGennes function in common with many other rare earth alloy systems. Alloys containing approximately equal proportions of light and heavy rare earth metals adopt the complicated Sm. structure and, as a result, display a complex magnetic structure. The light rare earth rich alloys display the d.h.c.p. crystallographic structure like Pr and Nd. The magnetic properties of the ferrimagnetic d.h.c.p, alloys are accounted for in terms of a two sublattice model of magnetism

HYDROBASE : a database of hydrographic stations and tools for climatological analysis

This report documents the organization, functionality, and algorithms of a software package which operates as a database manager and toolset for climatological analysis of hydrographic station data. It details the methods of quality control used in constrction of the small, but growing, database and discusses some of the improvements HydroBase methods offer over existing gridded databases, including a short comparison to Levitus's World Ocean Atlas 1994 package. A large porton of this technical reference is devoted to describing the software modules and providing examples for their use.Funding was provided by the National Science Foundation through Grant OCE91-03364 and the National Oceanic and Atmospheric Administration through Contract Nos. NA36GP0137 and NA46GP0303