Browsing by Author "Hobbs, Stephen"

Browsing by Author "Hobbs, Stephen"

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  • Physics-based clutter model for geosynchronous synthetic aperture radar 
    Convenevole, Carlo; Hobbs, Stephen (IEEE, 2020-06-02)
    In this paper the land clutter literature is briefly discussed and a need for a new class of clutter models for the Geosynchronous Synthetic Aperture Radar System Performance Assessment is shown. A new physics-based clutter ...
  • PRIMA: Precursor Rendezvous for Impact Mitigation of Asteroids. Summary of the Group Design Project, MSc in Astronautics and Space Engineering 2006/07 
    Hobbs, Stephen (2007-01-01)
    Students of the MSc course in Astronautics and Space Engineering 2006/07 at Cranfeld University took the Precursor Rendezvous for Impact Mitigation of Asteroids (PRIMA) mission as one of their group projects. This report ...
  • Quantifying improvements in debris risk analysis using a constellation of spaceborne optical sensors 
    D'Anniballe, Antonio; Felicetti, Leonard; Hobbs, Stephen (International Astronautical Federation (IAF), 2023-10-06)
    As the number of resident space objects (RSO) increases, operators face growing pressure for more accurate surveillance and collision risk analysis systems. Most of the space situational awareness domain depends today on ...
  • A Quantitative study of kite performance in natural wind with application to kite anemometry 
    Hobbs, Stephen (Cranfield University, 1986-04)
    Although kites have been around for hundreds of years and put to many uses, there has so far been no systematic study of their performance. This research attempts to fill this need, and considers particularly the performance ...
  • Research progress on geosynchronous synthetic aperture radar 
    Hu, Cheng; Chen, Zhiyang; Li, Yuanhao; Dong, Xichao; Hobbs, Stephen (Elsevier, 2021-05-04)
    Based on its ability to obtain two-dimensional (2D) high-resolution images in all-time and all-weather conditions, spaceborne synthetic aperture radar (SAR) has become an important remote sensing technique and the study ...
  • Signal analysis for an entomological radar with a vertical nutating beam 
    Hobbs, Stephen; Allsopp, K.; Wolf, W. (2003-09-19)
    This report documents the signal analysis procedures developed at Cran- field University for ground based entomological radars. The radars use a nutating vertical beam, allowing target (individual insect) position and ...
  • Simulation of rigidly-linked nanosatellites 
    Lecuyot, Arnaud; Hobbs, Stephen; Honstvet, Ian (2004-12-18)
    Rigidly linked nanosatellites are simulated as part of a PhD research on a new concept of space structure. Applications include a 1D interferometer in Earth and Lagrange orbits and a 3D Solar concentrator in Earth and Moon ...
  • Space weather warning system 
    Hobbs, Stephen (Cranfield University, 2012-09-27)
    Students of the MSc course in Astronautics and Space Engineering 2011–12 at Cranfield University studied a space weather warning mission for their group project. The mission was inspired by the Space Weather Diamond ...
  • Surface layer profiles of air temperature and humidity measured from unmanned aircraft 
    Hobbs, Stephen; Dyer, David; Courault, Dominique; Olioso, Albert; Lagouarde, Jean-Pierre; Kerr, Yann; Mcaneney, John; Bonnefond, Jean (2002-09-01)
    The atmospheric surface layer couples processes in the atmosphere with those at the land surface, but is not fully understood for heterogeneous land surfaces. A small remotely piloted aircraft was flown during the ReSeDA ...
  • System design for geosynchronous synthetic aperture radar missions 
    Hobbs, Stephen; Mitchell, Cathryn; Forte, Biagio; Holley, Rachel; Snapir, Boris; Whittaker, Philip (IEEE, 2014-05-08)
    Geosynchronous synthetic aperture radar (GEO SAR) has been studied for several decades but has not yet been implemented. This paper provides an overview of mission design, describing significant constraints (atmosphere, ...
  • System design for geosynchronous synthetic aperture radar missions 
    Hobbs, Stephen; Mitchell, C.; Forte, B.; Holley, R.; Snapir, Boris; Whittaker, P. (Institute of Electrical and Electronics Engineers, 2014-06-12)
    Geosynchronous synthetic aperture radar (GEO SAR) has been studied for several decades but has not yet been implemented. This paper provides an overview of mission design, describing significant constraints (atmosphere, ...
  • Target position and trajectory measurements by videogrammetry 
    Hobbs, Stephen (2003-11-11)
    This report documents the algorithms, data processing and software for the video photogrammetry ("videogrammetry") system developed at Cranfield University. Cranfield's system has been used successfully since 1999 on a ...
  • Videogrammetry: A practical method for measuring vegetation motion in wind demonstrated on wheat. 
    Hobbs, Stephen; Seynat, Cedric; Matakidis, Panos (Elsevier Science B.V., Amsterdam., 2007-02-10)
    Plant motion in wind is a common phenomenon but has rarely been quantified. Among other effects, plant motion is known to affect the quality (or “coherence”) of interferometric radar images although the loss of quality is ...
  • What might sustainability of the GEO region look like? 
    Kingston, Jenny; Felicetti, Leonard; Hobbs, Stephen (Society of Photo-Optical Instrumentation Engineers (SPIE), 2021-10-12)
    Sustainability in space is often discussed, but as a community we are only gradually learning what it actually means. To inform this understanding, a set of three parallel projects ran at Cranfield University (Oct 2020 to ...
  • Wheat video experiments 2000 data archive 
    Hobbs, Stephen; Seynat, Cedric (2000)
    Observations of wheat motion in wind were made through the later part of the growing season (June - August) for wheat on Cranfield Airfield in 2000. The data collected include stereo videogrammetric measurements of the ...
  • Widespread occurrence of anomalous C-band backscatter signals in arid environments caused by subsurface scattering 
    Wagner, Wolfgang; Lindorfer, Roland; Melzer, Thomas; Hahn, Sebastian; Bauer-Marschallinger, Bernhard; Morrison, Keith; Calvet, Jean-Christophe; Hobbs, Stephen; Quast, Raphael; Greimeister-Pfeil, Isabella; Vreugdenhil, Mariette (Elsevier, 2022-04-22)
    Backscatter measured by scatterometers and Synthetic Aperture Radars is sensitive to the dielectric properties of the soil and normally increases with increasing soil moisture content. However, when the soil is dry, the ...