Electric-vehicle batteries

Electric vehicles that can't reach trolley wires need batteries. In the early 1900's electric cars disappeared when owners found that replacing the car's worn-out lead-acid battery costs more than a new gasoline-powered car. Most of today's electric cars are still propelled by lead-acid batteries. General Motors in their prototype Impact, for example, used starting-lighting-ignition batteries, which deliver lots of power for demonstrations, but have a life of less than 100 deep discharges. Now promising alternative technology has challenged the world-wide lead miners, refiners, and battery makers into forming a consortium that sponsors research into making better lead-acid batteries. Horizon's new bipolar battery delivered 50 watt-hours per kg (Wh/kg), compared with 20 for ordinary transport-vehicle batteries. The alternatives are delivering from 80 Wh/kg (nickel-metal hydride) up to 200 Wh/kg (zinc-bromine). A Fiat Panda traveled 260 km on a single charge of its zinc-bromine battery. A German 3.5-ton postal truck traveled 300 km with a single charge in its 650-kg (146 Wh/kg) zinc-air battery. Its top speed was 110 km per hour     

Automatic target recognition of time critical moving targets using1D high range resolution (HRR) radar

Synthetic Aperture Radar (SAR) imaging and Automatic Target Recognition (ATR) of moving targets pose a significant challenge due to the inherent difficulty of focusing moving targets. As a result, ATR of moving targets has recently received increased interest. High Range Resolution (HRR) radar mode offers an approach for recognizing moving targets by forming focused HRR profiles with significantly enhanced target-to-(clutter+noise) (T/(C+N)) via Doppler filtering and/or clutter cancellation. A goal of HRR ATR transition is the implementation and evaluation of algorithms exhibiting robustness under extended operating conditions (EOC). The public domain Moving and Stationary Target Acquisition and Recognition (MSTAR) data set was used to study 1D template-based ATR development and performance. Due to the unavailability of a statistically significant moving ground target data set, this approach was taken as an interim step in assessing the separability of ground targets when using range only discriminants. This report summarizes the data and algorithm methodology, simulated performance results, and recommendations     

Integrated CIS VLF/Omega receiver design

The design of an integrated Russian-VLF/Omega receiver implemented on a TMS320C30-microprocessor-based SPECTRUM plug-in board installed in a PC-compatible portable computer is presented. The system also requires an external antenna, pre-amp, and frequency reference. The SPECTRUM board digitizes the RF signal to 16 b and then digitally mixes with the sines and cosines of the three Russian frequencies plus 10.2, 11-1/3, and 13.6 kHz. The mixer outputs are low-pass filtered, and the comb filters are implemented for the respective epochs. The computer accesses and processes the comb filter outputs, calculating and logging signal phase and amplitude. The design allows for easy future expansion to include unique and VLF communication frequencies     

Active learning for advanced students: The Center for Integrated Space Weather Modeling graduate summer school

In recent years there has been considerable research in undergraduate physics education regarding the application to classroom instruction of techniques that are generally referred to as active engagement techniques. However, in very few cases have such pedagogical strategies been applied to graduate-level instruction. In this paper we describe an innovative application of a variety of active engagement techniques at the graduate summer school conducted by the Center for Integrated Space Weather Modeling, a Science and Technology Center funded by the National Science Foundation. We believe that the model presented here can serve as a valuable guide to other group contemplating space physics education at all levels, as well as graduate education generally.     

New generation of inertial clusters for standby instruments based on vibrating sensors

The robustness, reliability and low-cost of the Quapason present great advantages for a new type of application: integrated standby instruments used in military and commercial aircrafts. This paper deals with the specific requirements of these instruments and demonstrates the suitability of the Quapason for these applications where cheap sensors with good performance are essential.     

Application of time-variable process noise in terrestrial reference frames determined from VLBI data

In recent years, Kalman filtering has emerged as a suitable technique to determine terrestrial reference frames (TRFs), a prime example being JTRF2014. The time series approach allows variations of station coordinates that are neither reduced by observational corrections nor considered in the functional model to be taken into account. These variations are primarily due to non-tidal geophysical loading effects that are not reduced according to the current IERS Conventions (2010). It is standard practice that the process noise models applied in Kalman filter TRF solutions are derived from time series of loading displacements and account for station dependent differences. So far, it has been assumed that the parameters of these process noise models are constant over time. However, due to the presence of seasonal and irregular variations, this assumption does not truly reflect reality. In this study, we derive a station coordinate process noise model allowing for such temporal variations. This process noise model and one that is a parameterized version of the former are applied in the computation of TRF solutions based on very long baseline interferometry data. In comparison with a solution based on a constant process noise model, we find that the station coordinates are affected at the millimeter level.     

Beam Shape Loss and Surveillance Optimization for Pencil Beam Arrays

A radar in its surveillance mode requires the programming of the radar beam in fixed angular increments throughout the surveillance volume. Though radar coverage of the volume is complete, returns from possible targets differing only in angular position generally have unequal signal strengths. This is due to both beam shape and multiple beam coverage. The resulting nonuniformity in signal strength results in a loss factor termed beam shape loss (BSL). This correspondence contains the results of a valid computational procedure for determining this loss factor for the case of an electronically steerable array in a search mode. Results consist of curves showing BSL for a wide range of system parameters and for various target types. In addition, it is shown how optimum search beam locations can be determined from the BSL computations.