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The process of lock acquisition in a high-f inesse suspended Fabry–Perot cavity used in the LIGO 40-m interferometer is numerically simulated. The simulation, including a model of the cavity optical transient response as the mirrors swing through resonance, demonstrates that acquisition of lock by the controller depends on the relative velocity of the(More)
The latest coupled configuration of the Met Office Unified Model (Global Coupled configuration 2, GC2) is presented. This paper documents the model components which make up the configuration (although the scientific description of these components is detailed elsewhere) and provides a description of the coupling between the components. The performance of(More)
We report on a novel high-sensitivity method to characterize and improve mode matching into optical cavities. This method is based on heterodyne detection of cylindrical transverse cavity modes. A specially designed annular-segmented photodiode is used to measure the amplitude of nonresonant modes reflected by the cavity. Our measurements allow us to(More)
This article describes the UK Met Office Global Seasonal forecast system version 5 (GloSea5). GloSea5 upgrades include an increase in horizontal resolution in the atmosphere (N216–0.7◦) and the ocean (0.25◦), and implementation of a 3D-Var assimilation system for ocean and sea-ice conditions. GloSea5 shows improved year-to-year predictions of the major(More)
An optical-loss measurement system based on a resonant Fabry-Perot cavity at 1.06 microm in vacuum has been developed for independent monitoring of the cavity total loss and the optical absorption loss. Maintenance of cavity resonance over a one-month period allows the assessment of long-term degradation of the cavity optics in the presence of outgassing(More)
A nine-aperture, wide-field Fizeau imaging telescope has been built at the Lockheed-Martin Advanced Technology Center. The telescope consists of nine, 125 mm diameter collector telescopes coherently phased and combined to form a diffraction-limited image with a resolution that is consistent with the 610 mm diameter of the telescope. The phased field of view(More)
This paper details the construction of a sub-nanosecond pulse generator capable of delivering 250 kV into a high impedance load. The pulse width is approximately 600ps with a voltage rise of up to 1 MV/ns. The pulse rise-time can be adjusted by manipulation of a peaking gap, whereas the pulse-width can be changed by adjusting a novel tail-cut switch located(More)
Focusing Impulse Radiating Antennas allow the application of intense electric fields to biological tissue with centimeter spatial resolution. At low electric field strength, the scattered electromagnetic waves from the focal volume can be used to obtain information on the complex permittivity of the tissue at this location. Since the permittivity of tumor(More)
Star-9 is an experimental demonstration of distributed aperture imaging built at the Lockheed Martin Advanced Technology Center. White light from a scene generator enters an array of nine actively controlled telescopes, and is combined at a focused image plane. This paper describes the algorithms used to automatically bring each telescope's relative(More)
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