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pro vyhledávání: '"John A. Christian"'
A Tutorial on Horizon-Based Optical Navigation and Attitude Determination With Space Imaging Systems
Autor:
John A. Christian
Publikováno v:
IEEE Access, Vol 9, Pp 19819-19853 (2021)
Images of a nearby celestial body collected by a camera on an exploration spacecraft contain a wealth of actionable information. This work considers how the apparent location of the observed body’s horizon in a digital image may be used to infer th
Externí odkaz:
https://doaj.org/article/ef37796ca7e24c9d86d64755c79f9f77
Autor:
John A. Christian, John L. Crassidis
Publikováno v:
IEEE Access, Vol 9, Pp 25768-25794 (2021)
Images of starfields collected by a projective camera are useful for a variety of scientific and engineering purposes. This utility is exemplified by star trackers, which are amongst the most commonly used sensors for determining the attitude of mode
Externí odkaz:
https://doaj.org/article/54a9021829084b8584771418dc5e8f06
Autor:
Devin T. Renshaw, John A. Christian
Publikováno v:
Journal of Imaging, Vol 6, Iss 5, p 33 (2020)
Many modern sensing systems rely on the accurate extraction of measurement data from digital images. The localization of edges and streaks in digital images is an important example of this type of measurement, with these techniques appearing in many
Externí odkaz:
https://doaj.org/article/8826fbf0377c4f6ab3e89b9cd44317c6
Publikováno v:
Algorithms, Vol 12, Iss 12, p 245 (2019)
Many scientific and engineering problems benefit from analytic expressions for eigenvalue and eigenvector derivatives with respect to the elements of the parent matrix. While there exists extensive literature on the calculation of these derivatives,
Externí odkaz:
https://doaj.org/article/cb62745ac5fd4ababf7aea1be30fef12
StarNAV: Autonomous Optical Navigation of a Spacecraft by the Relativistic Perturbation of Starlight
Autor:
John A. Christian
Publikováno v:
Sensors, Vol 19, Iss 19, p 4064 (2019)
Future space exploration missions require increased autonomy. This is especially true for navigation, where continued reliance on Earth-based resources is often a limiting factor in mission design and selection. In response to the need for autonomous
Externí odkaz:
https://doaj.org/article/43b70c8839b24f83944cfdb92b4c1883
Publikováno v:
Journal of Guidance, Control, and Dynamics. 46:277-285
Images from cameras are a common source of navigation information for a variety of vehicles. Such navigation often requires the matching of observed objects (e.g., landmarks, beacons, stars) in an image to a catalog (or map) of known objects. In many
Autor:
T. J. Fudge, Benjamin H. Hills, Annika N. Horlings, Nicholas Holschuh, John Erich Christian, Lindsey Davidge, Andrew Hoffman, Gemma K. O'Connor, Knut Christianson, Eric J. Steig
Publikováno v:
Journal of Glaciology. 69:538-550
Hercules Dome, Antarctica, has long been identified as a prospective deep ice core site due to the undisturbed internal layering, climatic setting and potential to obtain proxy records from the Last Interglacial (LIG) period when the West Antarctic i
Publikováno v:
Acta Astronautica. 197:220-234
Many marine-terminating outlet glaciers have retreated rapidly in recent decades, but these changes have not been formally attributed to anthropogenic climate change. A key challenge for such an attribution assessment is that if glacier termini are s
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::f428788b1f0aa6c2ec4177b1a3aa23eb
https://doi.org/10.5194/egusphere-egu23-11044
https://doi.org/10.5194/egusphere-egu23-11044
Publikováno v:
The Cryosphere. 16:2725-2743
Many marine-terminating outlet glaciers have retreated rapidly in recent decades, but these changes have not been formally attributed to anthropogenic climate change. A key challenge for such an attribution assessment is that if glacier termini are s