Andrew O'Brien

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Considering waves in the arteries as infinitesimal wave fronts rather than sinusoidal wavetrains, the change in pressure across the wave front, dP, is related to the change in velocity, dU, that it induces by the "water hammer" equation, dP=+/-rhocdU, where rho is the density of blood and c is the local wave speed. When only unidirectional waves are(More)
In this paper we describe the development of a low cost, high power coherent-on-receiver radar. The unit has a 25kW peak transmit power and is capable of accurately measuring velocity as well as range. The design of the radar is optimized for marine surveillance, although the techniques developed have general application. The radar system is validated(More)
Ramp metering is a dynamic traffic management tool used to eliminate or reduce the duration of congestion on motorways. A ramp metering implementation can present some problems to the adjacent arterial network. One source of these problems is the treatment of motorways and arterial network as two separate areas of control. This paper presents three novel(More)
The CubeSat Radiometer Radio Frequency Interference Technology Validation (CubeRRT) mission is developing a 6U CubeSat system to demonstrate radio frequency interference (RFI) detection and mitigation technologies for future microwave radiometer remote sensing missions. CubeRRT will perform observations of Earth brightness temperatures from 6-40 GHz using a(More)
Passive radars use transmissions from signals of opportunity in order to locate targets. The absence of a dedicated transmitter reduce the cost, complexity and detectability of the radar as compared to active radar systems. This paper investigates — for the first time — the use of signals of a metropolitan-wide terrestrial positioning system(More)
This presentation will include an overview of the recently launched NASA CYGNSS mission Level 1 calibration algorithms and their on-orbit validation [1], [2]. The validation of the Level 1 calibration will be performed in several steps, including a) a detailed noise floor analysis to assess the observed on-orbit noise power levels over the open ocean, b)(More)
CONCLUSION Our data showed high procedural success rate of early PCI strategy in pts with OHCA. OHCA caused by ACS may be missed if decision-making is based on ECG alone. The percentage of pts free of neurological impairment in the PCI group is high. Interventional cardiologist should become part of a “post-resuscitation team” in order to optimize(More)
This paper provides a comparison of scattering models for near-specular bistatic scattering from rough surfaces. While the Geometrical Optics (GO) approximation is widely accepted for surfaces having large roughness compared to the electromagnetic wavelength, small differences in the literature exist between GO formulations. The Physical Optics (PO) and(More)
  • Matthew Buchanan, Andrew O'Brien
  • 2017 IEEE International Geoscience and Remote…
  • 2017
GNSS-R (Global Navigation Satellite System Reflectometry) is being increasingly used in Earth remote sensing applications; however, up until now, dual-polarized data from spaceborne instruments has not been available. Recently, the radar aboard the SMAP satellite has provided raw received signal data on the GPS L2C frequency band. This data is(More)