Techniques for Radiotracking and Biotelemetry of Coolwater Sport Fish in Norfork Reservoir, Arkansas

Sonic and radio transmitters were implanted in 19 fish in Norfork Reservoir (12 walleye and seven striped bass) to determine the better transmitter type for two coolwater fish species in riverine and deep basin habitats. Radio transmit ters were equipped with either internal or external antennas and both radio and sonic transmitters had thermistors. Sonic transmitters proved superior to radio transmitters forlocating tagged fish after stratification. Fish implanted with radk transmitters were not found after July while fish implanted with sonic transmitters were located 87% of the time. Walleyt remained in the spring-fed riverine portion ofthe reservoir where water temperatures never exceeded 22 C and dissolvec oxygen concentrations were greater than nine mg/L; an area not conducive to listen for sonic transmitters because o high extraneous noise from current velocity and boat traffic. Striped bass were confined to the large basin of the dam during critical minimal conditions in the summer; an area not favorable to listen for radio transmitters because of watei depths striped bass tended to occupy and thermal stratification. Heavy angler harvest ofimplanted fishes resulted in an exploitation study initiated by the Arkansas Game and Fish Commission and the Missouri Department ofConservation in 1995

Power density measurements in the near field of the DSS 13 26-meter antenna

Power density measurements were made at Deep Space Station (DSS) 13 in the near field of the 26-m antenna to determine if radio frequency (rf) fields generated by the 20-kW transmitters could be responsible for the failure of three solid state rf amplifiers. These amplifiers are used in the Search for Extraterrestrial Intelligence (SETI) Radio Spectrum Surveillance System, which is currently located at the site. Measurements were made independently for one transmitter at 7150 MHz, and both transmitters together. Measurement results are tabulated and compared with predicted power densities under the measurement conditions. The results agree with the predictions within a factor of two. The predictions appear to give worst case values. Measurements indicated that amplifier failures are not attributable to the transmitter

Fate and Survival of Radio-marked Montezuma Quail

Montezuma quail (Cyrtonyx montezumae) represent one of the least studied North American quail species, particularly in Texas. This lack of information may be partly due to their secretive nature and difficulty of capturing. We provide the first published report of fate of radio-marked Montezuma quail in Texas. We captured, radio-marked, and released 14 Montezuma quail on Elephant Mountain (n = 9) and Davis Mountain Preserve (n = 5) during 2000-2005. We used 2 methods of attachment for pendant style neck-loop radio transmitters. Body-loop transmitters were affixed to quail captured at the Davis Mountain Preserve whereas both body-loop and neck-loop were used at Elephant Mountain. All radio-marked Montezuma quail died within a relatively short period (1-16 days). Causes of mortality for most Montezuma quail were attributed to raptors (n = 9), mammals (n = 1), and miscellaneous (n = 4). Because this low survival rate would not sustain a natural population, we suspect trapping, handling, and/or radio-marking negatively affected survival. It is possible that transmitters potentially restricted escape movements or interfered with other behavior thereby making Montezuma quail more vulnerable to predation. Traditional techniques used to affix radio transmitters or transmitter design itself need to be refined if Montezuma quail are to be studied using radio telemetry

Radio Wavelength Transients: Current and Emerging Prospects

Known classes of radio wavelength transients range from the nearby--stellar flares and radio pulsars--to the distant Universe--\gamma-ray burst afterglows. Hypothesized classes of radio transients include analogs of known objects, e.g., extrasolar planets emitting Jovian-like radio bursts and giant-pulse emitting pulsars in other galaxies, to the exotic, prompt emission from \gamma-ray bursts, evaporating black holes, and transmitters from other civilizations. A number of instruments and facilities are either under construction or in early observational stages and are slated to become available in the next few years. With a combination of wide fields of view and wavelength agility, the detection and study of radio transients will improve immensely.Comment: to appear in proceedings of Hot-wiring the Transient Universe, 2008 March issue of Astronomische Nachrichte

A Polyphase Multipath Technique for Software-Defined Radio Transmitters

Transmitter circuits using large signal swings and hard-switched mixers are power-efficient, but also produce unwanted harmonics and sidebands, which are commonly removed using dedicated filters. This paper presents a polyphase multipath technique to relax or eliminate filters by canceling a multitude of harmonics and sidebands. Using this technique, a wideband and flexible power upconverter with a clean output spectrum is realized in 0.13-mum CMOS, aiming at a software-defined radio application. Prototype chips operate from DC to 2.4 GHz with spurs smaller than -40 dBc up to the 17th harmonic (18-path mode) or 5th harmonic (6-path mode) of the transmit frequency, without tuning or calibration. The transmitter delivers 8 mW of power to a 100-Omega load (2.54 Vpp-diff voltage swing) and the complete chip consumes 228 mW from a 1.2-V supply. It uses no filters, but only digital circuits and mixer

Capacity scaling law by multiuser diversity in cognitive radio systems

This paper analyzes the multiuser diversity gain in a cognitive radio (CR) system where secondary transmitters opportunistically utilize the spectrum licensed to primary users only when it is not occupied by the primary users. To protect the primary users from the interference caused by the missed detection of primary transmissions in the secondary network, minimum average throughput of the primary network is guaranteed by transmit power control at the secondary transmitters. The traffic dynamics of a primary network are also considered in our analysis. We derive the average achievable capacity of the secondary network and analyze its asymptotic behaviors to characterize the multiuser diversity gains in the CR system.Comment: 5 pages, 2 figures, ISIT2010 conferenc

Implantation of Subcutaneous Radio Transmitters in the Harbor Seal (\u3ci\u3ePhoca vitulina\u3c/i\u3e)

Radio telemetry has become a standard tool for studying the behavior, physiology, life history traits, and population dynamics of marine mammals. Radio transmitters typically are attached to the hind flippers of pinnipeds or glued to the fur using marine epoxy or other cyanocrylare adhesives (Fedak et al. 1983, Bengtson 1993, Jeffries et al. 1993). Longterm data acquisition is difficult, however, because radio-flipper transmitters commonly tear from the webbing of the flipper and instruments that are glued to the fur are shed during the seasonal molt