Investigation of synchronous satellites for geodesy Quarterly progress report

Orbit calculations for synchronous geodetic satellites to observe continental drift and Chandler wobbl

Study of the global positioning system for maritime concepts/applications: Study of the feasibility of replacing maritime shipborne navigation systems with NAVSTAR

A geostationary reference satellite (REFSAT) that broadcasts every four seconds updated GPS satellite coordinates was developed. This procedure reduces the complexity of the GPS receiver. The economic and performance payoffs associated with replacing maritime stripborne navigation systems with NAVSTAR was quantified and the use of NAVSTAR for measurements of ocean currents in the broad ocean areas of the world was evaluated

Applications of remote sensing to stream discharge predictions

A feasibility study has been initiated on the use of remote earth observations for augmenting stream discharge prediction for the design and/or operation of major reservoir systems, pumping systems and irrigation systems. The near-term objectives are the interpolation of sparsely instrumented precipitation surveillance networks and the direct measurement of water loss by evaporation. The first steps of the study covered a survey of existing reservoir systems, stream discharge prediction methods, gage networks and the development of a self-adaptive variation of the Kentucky Watershed model, SNOPSET, that includes snowmelt. As a result of these studies, a special three channel scanner is being built for a small aircraft, which should provide snow, temperature and water vapor maps for the spatial and temporal interpolation of stream gages

Assessment of geophysical flows for zero-gravity simulation

The results of research relating to the feasibility of using a low gravity environment to model geophysical flows are presented. Atmospheric and solid earth flows are considered. Possible experiments and their required apparatus are suggested

Modern control concepts in hydrology

Two approaches to an identification problem in hydrology are presented based upon concepts from modern control and estimation theory. The first approach treats the identification of unknown parameters in a hydrologic system subject to noisy inputs as an adaptive linear stochastic control problem; the second approach alters the model equation to account for the random part in the inputs, and then uses a nonlinear estimation scheme to estimate the unknown parameters. Both approaches use state-space concepts. The identification schemes are sequential and adaptive and can handle either time invariant or time dependent parameters. They are used to identify parameters in the Prasad model of rainfall-runoff. The results obtained are encouraging and conform with results from two previous studies; the first using numerical integration of the model equation along with a trial-and-error procedure, and the second, by using a quasi-linearization technique. The proposed approaches offer a systematic way of analyzing the rainfall-runoff process when the input data are imbedded in noise

The Benchmark satellite Final report

Methods for satellite measurement of continental drift with earth rotation and mathematical logic for active attitude control of spin stabilized spacecraf

MONTE CARLO SIMULATIONS OF MUON PRODUCTION

Muon production requirements for a muon collider are presented. Production of muons from pion decay is studied. Lithium lenses and solenoids are considered for focussing pions from a target, and for matching the pions into a decay channel. Pion decay channels of alternating quadrupoles and long solenoids are compared. Monte Carlo simulations are presented for production of $\pi \rightarrow \mu$ by protons over a wide energy range, and criteria for choosing the best proton energy are discussed.Comment: Latex uses mu95.sty, 19 pages, 5 postscript figures. A postscript file can be seen at URL http://www.cap.bnl.gov/~cap/mumu/important.html Search for Publication

Vaginal-rectal colonization with group A streptococci in late pregnancy.

OBJECTIVE: To determine the vaginal-rectal colonization rate with group A streptococci in late pregnancy. METHODS: All patients delivering at a northern New England hospital over a 38 month period had 35-37 week vaginal-rectal swabs cultured for group A and group B streptococci, using selective media and slide agglutination. RESULTS: Six thousand nine hundred forty-four screening cultures were obtained. Among these 1,393 were positive for group B streptococci and 2 for group A streptococci, yielding colonization rates of 20.1% and 0.03%, respectively. CONCLUSIONS: Vaginal-rectal colonization with group A streptococci is rare, arguing against the need for establishing group A streptococcal screening programs in pregnancy. An approach for managing this uncommon finding is presented

HATS-1b: The First Transiting Planet Discovered by the HATSouth Survey

We report the discovery of HATS-1b, a transiting extrasolar planet orbiting the moderately bright V=12.05 G dwarf star GSC 6652-00186, and the first planet discovered by HATSouth, a global network of autonomous wide-field telescopes. HATS-1b has a period P~3.4465 d, mass Mp~1.86MJ, and radius Rp~1.30RJ. The host star has a mass of 0.99Msun, and radius of 1.04Rsun. The discovery light curve of HATS-1b has near continuous coverage over several multi-day periods, demonstrating the power of using a global network of telescopes to discover transiting planets.Comment: Submitted to AJ 10 pages, 5 figures, 6 table

Analytic Approximations for Transit Light Curve Observables, Uncertainties, and Covariances

The light curve of an exoplanetary transit can be used to estimate the planetary radius and other parameters of interest. Because accurate parameter estimation is a non-analytic and computationally intensive problem, it is often useful to have analytic approximations for the parameters as well as their uncertainties and covariances. Here we give such formulas, for the case of an exoplanet transiting a star with a uniform brightness distribution. We also assess the advantages of some relatively uncorrelated parameter sets for fitting actual data. When limb darkening is significant, our parameter sets are still useful, although our analytic formulas underpredict the covariances and uncertainties.Comment: 33 pages, 14 figure