Evaluation of LANDSAT-D Orbit Determination Using a Filter/Smoother (PREFER)

Simulated range and range rate data for five tracking stations were first generated using batch least squares orbit determination (GTDS). Then GTDS was used (in the differential correction mode) to produce a nominal trajectory which was input to PREFER. The GTDS differential correction (DC) run was made using models which differed from those used to produce the simulated data. These model differences were chosen to be fairly realistic approximations to the errors in the models actually used for operational orbit determination. Several different simulation runs were made with different types of model errors in order to determine the sensitivity to these errors. The nominal trajectory and the simulated measurement data were input to PREFER to produce a smoothed ephemeris file. Numerous runs of PREFER were made in which parameters describing the statistics of the model errors were varied. The likelihood function computed by the Kalman filter determined the ""best'' choice of input parameters. There was strong negative correlation between the likelihood function and the errors in the smoothed ephemeris

Resistant Self in Leadership: A Hermeneutical Conundrum

Autoethnography offers leadership study opportunities as it allows the texts to move between the self of the subject and the researcher who can themselves be a co-researched subject. In this sense texts moving between 'selves' represents a hermeneutical concern (or ‘language game’); that is it is possible to see the self as a text, in a context, and moving between selves, although not to gain access to the ‘original intent’ of the author; the text in this instance is in ‘our’ hands and as such transforming from the author in a new direction. As such, in this domain: “all understanding is interpretation, and all interpretation takes place in the medium of language which would allow the object to come into words and yet is at the same time the interpreter’s own language” (Gadamer, 1975: 350)

Computer program documentation user information for the RSO-tape print program (RSOPRNT)

A user's guide for the RSOPRNT, a TRASYS Master Restart Output Tape (RSO) reader is presented. Background information and sample runstreams, as well as, references, input requirements and options, are included

Pion Charge Exchange on Deuterium

We investigate quantum corrections to a classical intranuclear cascade simulation of pion single charge exchange on the deuteron. In order to separate various effects the orders of scattering need to be distinguished and, to that end, we develop signals for each order of scattering corresponding to quasi-free conditions. Quantum corrections are evaluated for double scattering and are found to be large. Global agreement with the data is good.Comment: 30 pages, 12 figure

Computer program documentation user information for the MPAD trajectory tape print program (TRJPR1)

The Trajectory Tape Print Program (TRJPR1) was developed to print applicable information from a Space Trajectory tape created by the Mission Planning and Analysis Division (MPAD) in the MPAD Common Format for the on-orbit phase of the Mission. Instructions for TRJPR1's use are given

Geomagnetic modeling by optimal recursive filtering

The results of a preliminary study to determine the feasibility of using Kalman filter techniques for geomagnetic field modeling are given. Specifically, five separate field models were computed using observatory annual means, satellite, survey and airborne data for the years 1950 to 1976. Each of the individual field models used approximately five years of data. These five models were combined using a recursive information filter (a Kalman filter written in terms of information matrices rather than covariance matrices.) The resulting estimate of the geomagnetic field and its secular variation was propogated four years past the data to the time of the MAGSAT data. The accuracy with which this field model matched the MAGSAT data was evaluated by comparisons with predictions from other pre-MAGSAT field models. The field estimate obtained by recursive estimation was found to be superior to all other models

Magnetoresistance and efficiency measurements of Alq(3)-based OLEDs

Copyright 2007 by the American Physical Society. Article is available at

Low-dose alum application trialled as a management tool for internal nutrient loads in Lake Okaro, New Zealand

Aluminium sulfate (alum) was applied to Lake Okaro, a eutrophic New Zealand lake with recurrent cyanobacterial blooms, to evaluate its suitability for reducing trophic status and bloom frequency. The dose yielded 0.6 g aluminium m–3 in the epilimnion. Before dosing, pH exceeded 8 in epilimnetic waters but was optimal for flocculation (6–8) below 4 m depth. After dosing, there was no significant change in water clarity, hypolimnetic pH decreased to 5.5, and soluble aluminium exceeded recommended guidelines for protection of freshwater organisms. Epilimnetic phosphate concentrations decreased from 40 to 5 mg m–3 and total nitrogen (TN):total phosphorus (TP) mass ratios increased from 7:1 to 37:1. The dominant phytoplankton species changed from Anabaena spp. before dosing, to Ceratium hirudinella , then Staurastrum sp. after dosing. Detection of effectiveness of dosing may have been limited by sampling duration and design, as well as the low alum dose. The decrease in hypolimnetic pH and epilimnetic TP, and increase in Al3+ and chlorophyll a, are attributed to the low alkalinity lake water and coincidence of alum dosing with a cyanobacterial bloom and high pH

The composition of phosphate granules in the digestive glands of marine prosobranch gastropods: variation in relation to taxonomy

The composition of some 1150 phosphate granules in the digestive glands of over 40 species of marine prosobranch gastropods has been surveyed using a simple preparation technique and semiquantitative SEM x-ray microanalysis. Spectral peaks for Mg, K, Ca, Mn, Fe and Zn were compared to that of P. Four major types of phosphate granule can be recognised, each generally characteristic of a taxonomic grouping: high Mg in archaeogastropods and littorinids, multiple metal in higher mesogastropods, and, in neogastropods, Mg-Ca in muricoideans and high Zn in buccinoideans. At least one Conus species (C. ventricosus) has high-Mg granules. Some causes of variation in granule composition are discussed: speculatively, it is suggested a palaeoenvironmental influence seems possible.info:eu-repo/semantics/publishedVersio