Browsing by Author "Urco, M."

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    Aperture-synthesis radar imaging with compressive sensing for ionospheric research
    (American Geophysical Union, 2019-06) Hysell, D. L.; Sharma, P.; Urco, M.; Milla, Marco
    Inverse methods involving compressive sensing are tested in the application of two-dimensional aperture-synthesis imaging of radar backscatter from field-aligned plasma density irregularities in the ionosphere. We consider basis pursuit denoising, implemented with the fast iterative shrinkage thresholding algorithm, and orthogonal matching pursuit (OMP) with a wavelet basis in the evaluation. These methods are compared with two more conventional optimization methods rooted in entropy maximization (MaxENT) and adaptive beamforming (linearly constrained minimum variance or often “Capon's Method.”) Synthetic data corresponding to an extended ionospheric radar target are considered. We find that MaxENT outperforms the other methods in terms of its ability to recover imagery of an extended target with broad dynamic range. Fast iterative shrinkage thresholding algorithm performs reasonably well but does not reproduce the full dynamic range of the target. It is also the most computationally expensive of the methods tested. OMP is very fast computationally but prone to a high degree of clutter in this application. We also point out that the formulation of MaxENT used here is very similar to OMP in some respects, the difference being that the former reconstructs the logarithm of the image rather than the image itself from basis vectors extracted from the observation matrix. MaxENT could in that regard be considered a form of compressive sensing.
    Palabras clave:Ionospheric irregularitiesImagingCompressive sensing
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    Madrigal database at Jicamarca: upgrading and unifictaing our databases
    (Instituto Geofísico del Perú, 2009) Urco, M.; Rideout, B.
    Several instruments utilized under different operation modes at the Jicamarca Radio Observatory (JRO) have allowed the study of the equatorial atmosphere and ionosphere for many years. Among others we have: the Incoherent Scatter Radar (ISR), the Jicamarca Bistatic Radar (JBR), Magnetometer, Ionosonda and JULIA radar. All instruments generate a huge amount of information, either raw or derived data. Each operation mode has its own database and it can be freely accessed through the Internet by their respective link at: http://jro.igp.gob.pe/database/; the search options, graphics and visualization are different depending on the experiment. JRO is under a process of data server upgrading, both software and hardware. This includes the unification of existing databases in Jicamarca, improving the search tools, access and visualization. The first stage of this process involves the transfer of Madrigal tools to the server: http://jro1.igp.gob.pe/madrigal which has a better performance and greater security, including the addition of new data and experiments to Madrigal. In this work we describe the main features of our new designed database, as well as the improvements and new options added to Madrigal.
    Palabras clave:Geophysical observatoryRadarIonosphere
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    Obtención de imágenes de "Spread F" usando multiprocesamiento
    (Instituto Geofísico del Perú, 2010) Urco, M.; Chau Chong Shing, Jorge Luis; Hysell, D.
    Diapositivas presentadas en el XIII Encuentro Científico Internacional, (ECI 2010v), realizado del 5 al 8 de enero de 2010 en la ciudad de Lima.
    Palabras clave:Procesamiento de imágenesAtmósferaIonósfera
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    SIMONe Peru: deployment and operations
    (Instituto Geofísico del Perú, 2020-06) Suclupe, J.; Kuyeng, K.; Milla, Marco; Chau, J.L.; Urco, M.; Pfeffer, N.; Clahsen, M.; Vierinen, J.; Erickson, P.
    SIMONe Peru is a modern multistatic specular meteor radar which allows measuring winds in the mesosphere and lower thermosphere (MLT) between 70 and 110 km in altitude. Its main objective is to study the atmospheric dynamic in this region. Moreover, the system provides a higher number of detections compared to other systems and gives good statistics from detections in this region. This system started operations on september 2019 in the central coast of Peru. This work presents a general outline of the SIMONe Peru system, as well as the some preliminary results that allow us to operate and monitor it.
    Palabras clave:Meteor radarAtmospheric dynamicsAeronomy