Altitude determination by Kalman filtering Third quarterly progress report

Mathematical background for dynamic, geometric, and statistical analyses and transformations for inertial attitude reference determination by Kalman filterin

Market Structure, Organizational Structure, and R&D Diversity

We examine the effects of market structure and the internal organization of firms on equilibrium R&D projects. We compare a monopolist's choice of R&D portfolio to that of a welfare maximizer. We next show that Sah and Stiglitz's finding that the market portfolio of R&D is independent of the number of firms under Bertrand competition extends to neither Cournot oligopoly nor a cartel. We also show that the ability of firms to pre-empt R&D by rivals along particular research paths can lead to socially excessive R&D diversification. Lastly, using Sah and Stiglitz's definition of hierarchy, we establish conditions under which larger hierarchies invest in smaller portfolios.

Attitude determination using a Kalman filter, volume II

Computer program for determining attitude of orbiting vehicle using Kalman filte

Attitude determination by Kalman filtering, volume I

Satellite attitude determination by simulation program using Monte Carlo sampling and Kalman-Schmidt filte

Max L. Friedersdorf and Michael J. Farrell to \u27Dear Senator,\u27 22 Spetember 1975

Typed letter signed dated 22 September 1975 from Max L. Friedersdorf & Michael J. Farrell, Director of Office of White House Visitors, to Dear Senator, re: White House tours, bicentennialhttps://egrove.olemiss.edu/joecorr_g/1048/thumbnail.jp

Data compression for the Cassini radio and plasma wave instrument

The Cassini Radio and Plasma Wave Science experiment will employ data compression to make effective use of the available data telemetry bandwidth. Some compression will be achieved by use of a lossless data compression chip and some by software in a dedicated 80C85 processor. A description of the instrument and data compression system are included in this report. Also, the selection of data compression systems and acceptability of data degradation is addressed

First-Order Vortex Lattice Melting and Magnetization of YBa2_2Cu3_3O$_{7-\delta}

We present the first non-mean-field calculation of the magnetization $M(T)$ of YBa$_2$Cu$_3$O$_{7-\delta}$ both above and below the flux-lattice melting temperature $T_m(H)$. The results are in good agreement with experiment as a function of transverse applied field $H$. The effects of fluctuations in both order parameter $\psi({\bf r})$ and magnetic induction $B$ are included in the Ginzburg-Landau free energy functional: $\psi({\bf r})$ fluctuates within the lowest Landau level in each layer, while $B$ fluctuates uniformly according to the appropriate Boltzmann factor. The second derivative $(\partial^2 M/\partial T^2)_H$ is predicted to be negative throughout the vortex liquid state and positive in the solid state. The discontinuities in entropy and magnetization at melting are calculated to be $\sim 0.034\, k_B$ per flux line per layer and $\sim 0.0014$~emu~cm$^{-3}$ at a field of 50 kOe.Comment: 11 pages, 4 PostScript figures in one uuencoded fil

Charging and Subsequent Dissipation of a Rover Wheel in the Lunar Polar Regions

As a roving vehicle moves along the lunar surface, electric charge will build up through tribo-charging. This charge collected by the roving object will have a dissipative path to either the surface or the ambient plasma, depending upon which path is most conductive. At the lunar terminator region and into nightside regions, the surface is very cold and becomes a very poor conductor. leaving the plasma as the dominant remediating current for dissipation. However, within lunar craters, even plasma currents become substantially reduced which then greatly increases electric 'dissipation times, This work will involve the advancement of the stepping astronaut charge model, by considering the charging and plasma dissipation of a rolling rover wheel, The objective of this work is to determine the nature of charging and discharging for a rover wheel as it rolls along the cold, plasma-starved lunar polar regions. The rotating wheel accumulates charge via contact electrification (tribo-charging) with the lunar regolith. This tribo-charging is dependent on the composition of the objects in contact, with insulators and conductors charging differently. Given the environmental plasma in the region, we then determine the dissipation time for the wheel to bleed off its excess charge into the surrounding plasma. A model of the rover wheel rotating continuously over a surface regolith within a polar crater has been applied. The environmental plasma has been described previously. We define a new tribo-charging term specifically for the rotating system, with charge levels defined as a function of the wheel size, area in contact with the regolith, regolith particle size distribution, as well as the velocity at which the wheel is turning. We recognize that as charged dust accumulates and sticks to the wheel, this behaves effectively as a new current. Hence, the overall charging of the system should no longer vary linearly. and begin to show signs of saturation, We are devising a dust current term to model this charge-limiting effect, and will present the results in discussion