All roads lead to Rome: channelling inter-campus, interlibrary and off-campus requests through a single user interface

The message from remote library clients is clear and unequivocal - they want material quickly and easily. They would prefer not to have to differentiate between the three library services of intercampus, interlibrary, or off-campus requests - they just want a particular document or book forwarded to them as soon as possible. At the University of Southern Queensland Library, VDX software has been utilised to provide a single search and request interface for library material. Differentiating between individual clients,it displays and activates only those services for which a particular client is eligible. Remote undergraduates for example, have the ability to search and request from USQ catalogue only, while those students eligible for interlibrary loans can search and initiate requests across a range of catalogues. Whilst simplifying processes for clients, the challenge to Library staff has been to successfully manipulate the software and work processes to handle this complex arrangement. This paper will discuss the introduction of this new initiative focusing on the following issues: - Background - Client view - Dual services and associated challenges - Impact on staff - Improvements planned in the next six months - Marketing - Conclusio

Radar scatterometry - An active remote sensing tool

Radar scatterometer for measuring scattering coefficient variation with angle, wavelength, and polarizatio

Design data for radars based on 13.9 GHz Skylab scattering coefficient measurements

The author has identified the following significant results. Measurements made at 13.9 GHz with the radar scatterometer on Skylab have been combined to produce median curves of the variation of scattering coefficient with angle of incidence out to 45 deg. Because of the large number of observations, and the large area averaged for each measured data point, these curves may be used as a new design base for radars. A reasonably good fit at larger angles is obtained using the theoretical expression based on an exponential height correlation function and also using Lambert's law. For angles under 10 deg, a different fit based on the exponential correlation function, and a fit based on geometric optics expressions are both reasonably valid

RAWS: The spaceborne radar wind sounder

The concept of the Radar Wind Sounder (RAWS) is discussed. The goals of the RAWS is to estimate the following three qualities: the echo power, to determine rain rate and surface wind velocity; the mean Doppler frequency, to determine the wind velocity in hydrometers; and the spread of the Doppler frequency, to determine the turbulent spread of the wind velocity. Researchers made significant progress during the first year. The feasibility of the concept seems certain. Studies indicate that a reasonably sized system can measure in the presence of ice clouds and dense water clouds. No sensitivity problems exist in rainy environments. More research is needed on the application of the radar to the measurement of rain rates and winds at the sea surface

Skylab-4 radar scatterometer measurements over land

The author has identified the following significant results. Analysis of the SL4 S193 scatterometer observations shows that the winter measurements were reasonably consistent with summer measurements. The signals over land fall-off more rapidly in winter than in summer, probably because of the lack of vegetation return in winter; but the winter and summer results over land do not differ enough to cause changes in the general conclusions for the design of radars to be constructed for future space use. No consistent difference was found between snow-covered and snow-free terrain radar returns. The oceanic returns in winter were significantly different from those in summer, with a much less rapid fall-off with angle and a lower return at vertical. This is a true seasonal bias, for the winter seas tend to be much stormier than those in summer

Lattice-induced non-adiabatic frequency shifts in optical lattice clocks

We consider the frequency shift in optical lattice clocks which arises from the coupling of the electronic motion to the atomic motion within the lattice. For the simplest of 3-D lattice geometries this coupling is shown to only affect clocks based on blue-detuned lattices. We have estimated the size of this shift for the prospective strontium lattice clock operating at the 390 nm blue-detuned magic wavelength. The resulting fractional frequency shift is found to be on the order of $10^{-18}$ and is largely overshadowed by the electric quadrupole shift. For lattice clocks based on more complex geometries or other atomic systems, this shift could potentially be a limiting factor in clock accuracy.Comment: 5 page

Scanning wind-vector scatterometers with two pencil beams

A scanning pencil-beam scatterometer for ocean windvector determination has potential advantages over the fan-beam systems used and proposed heretofore. The pencil beam permits use of lower transmitter power, and at the same time allows concurrent use of the reflector by a radiometer to correct for atmospheric attenuation and other radiometers for other purposes. The use of dual beams based on the same scanning reflector permits four looks at each cell on the surface, thereby improving accuracy and allowing alias removal. Simulation results for a spaceborne dual-beam scanning scatterometer with a 1-watt radiated power at an orbital altitude of 900 km is described. Two novel algorithms for removing the aliases in the windvector are described, in addition to an adaptation of the conventional maximum likelihood algorithm. The new algorithms are more effective at alias removal than the conventional one. Measurement errors for the wind speed, assuming perfect alias removal, were found to be less than 10%

Large space antenna technology applied to radar-imaging, rain-rate measurements, and ocean wind sensing

During the last decade, the utility of spaceborne microwave remote sensing systems for ocean windspeed measurement, ocean wave imaging and sea ice studies was demonstrated. Development of large space antennas offers some interesting possibilities for rain rate measurements, ocean and ice studies, and radar imaging. The joint use of active and passive sensors using the 15 m antenna for ocean, ice, and soil moisture studies; rain rate measurements; and radar imaging is considered. Verification of the frequency agile rain radar concept with Shuttle offers the possibility of much needed rain rate statistics over the ocean