2 results
Compact polarimetry for automotive applications
- Christian Erhart, Steffen Lutz, Marc A. Mutschler, Philipp A. Scharf, Thomas Walter, Hubert Mantz, Robert Weigel
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- Journal:
- International Journal of Microwave and Wireless Technologies / Volume 11 / Issue 2 / March 2019
- Published online by Cambridge University Press:
- 02 January 2019, pp. 114-120
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- Article
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Though compact polarimetric approaches have been developed and applied in space and geo researching systems they have not been taken into consideration in automotive applications, yet. A sensor system has been designed to conduct polarimetric measurements in the 77 GHz frequency band, which is permitted for automotive usage. This system is able to transceive linearly as well as circularly polarized electromagnetic continuous waves. Depending on the case of application, the frequency output can be set statically or modulated over time within adjustable parameters. Hence, a variety of compact polarimetric modes can be performed and compared with full polarimetric approaches. Two compact polarimetric modes, dual-circular polarimetric mode, and circular-transmit-linear-receive, will be introduced and applied in this contribution. Their operability in this frequency range will be investigated after the microstrip antennas as well as the beam focusing dielectrical lense are characterized. Finally, results of a realistical measurement set-up will confirm the practicability of compact polarimetric approaches for double bounce recognition.
3 - Written Capitals and Capital Topography: Berlin and Washington in Travel Literature
- Edited by Andreas Daum, State University of New York, Buffalo, Christof Mauch, Universität zu Köln
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- Book:
- Berlin - Washington, 1800–2000
- Published online:
- 05 January 2013
- Print publication:
- 26 December 2005, pp 51-78
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Summary
There is an old saying that cities can be perceived as books. The German author Ludwig Boerne wrote in the early nineteenth century: “Paris can be called an open book - wandering through its streets is reading.” Franz Hessel, wandering through Berlin in the 1920s, gives the same metaphor a more precise meaning: “Flanerie is a way of reading the streets, where people's faces, shops, window displays, outdoor cafes, cars, tracks and trees become a series of letters, which together form the words, sentences, and pages of a book that is always new.”
The metaphor of “reading cities like books” has always appealed to writers and readers because it turns the city experience into a refined intellectual activity. The world as an “open book” is among the most venerable metaphors in the Western literary tradition. Travel literature is thus not only something for a reader to experience but also source material for historians. This metaphor is especially appealing to literary critics, who are accustomed to reading texts and feel at home reading texts about texts. It offers them an account of what might be going on when one looks at and wanders through cities.
What does it mean to read a city? One might turn to semiotic theory. Roland Barthes, for example, suggests in his essay “Semiology and Urbanism” that to read a city like a script that has to be deciphered, you must have in mind the task of structuralism: breaking down the city text into discrete units, arranging them alongside their opposite meanings, and then looking for the signs and signifiers that actually load the city with meanings. And that is how a city is to be read. The signifiers point to signified meanings that might be changing – or, in modern cities, that change constantly. The signifiers may rise to new meanings, the order of signs may be disturbed, the signs may be ambiguous or contradictory. The signs may always be in danger of being transitory or of being destroyed, but while a city has an abundance of signs (buildings, streets, and squares, for example), the meanings of these signs change over time. “The signifieds pass, the signifiers remain.” Moreover, a city changes its meaning not only in the content of its signs, but also in the relation of its parts. There are more texts in a city than one reader may see, and there are cities within a city arising from travelers’ different readings. Taking the process and the phenomenology of reading into consideration, it is clear that readers (and travelers) always write their own texts. The book that a city is supposed to be depends on how its readers fill the pages. There is no city and no capital – apart from the actual and historical readings to which they are subject.