Naslov
Aspects of terrestrial radio propagation in positioning systems

Autori
Virkes, Davor ; Kos, Tomislav ; Uljarević, Dijana

Vrsta, podvrsta i kategorija rada
Radovi u zbornicima skupova, cjeloviti rad (in extenso), znanstveni

Izvornik
Proceedings of 2nd GNSS Vulnerabilities and Solutions Conference. / - London : Delhi : Royal Institute of Navigation, 2009, 1-8

Skup
GNSS Vulnerabilities and Solutions Conference

Mjesto i datum
Baška, Hrvatska, 02.09.2009. - 05.09.2009

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
radio propagation ; GNSS ; indoor ; outdoor

Sažetak
The proposed paper will examine propagation of radio signals used for navigation purposes that originate from terrestrial sources, and solutions that have potential of extending satellite navigation systems coverage in secluded areas. Outdoors positioning by means of GNSS satellites is augmented by assistance of reference stations networks, such as CROPOS [1][2][3] in Croatia with reference stations set about 70km apart. Augmentation allows better positioning accuracy and integrity control. Augmentation system correction signal can be distributed using different networks. Signal availability of such augmentation system mostly depends upon the coverage of the used networks. Distribution over public GSM/GPRS/UMTS networks is very popular. VHF transmitters are also often used for distribution of correction signals. Geodetic precision positioning is impossible without reliable augmentation. Although the public cellular networks are declared to have coverage up to 99% of the territory, signal availability away from the communities becomes reduced, especially in forests and by terrain irregularities. The most restrictive situation in radio propagation is seclusion by barriers, present in underground environment or indoors. With advent of positioning receivers with improved reception it is now possible to maintain positioning to some degree even indoors. Because of signal diffraction and ducting, results of such positioning are imprecise. This mode of operation has a potential of maintaining a positioning receiver ready for outdoor measurements avoiding long time to the first fix problem. In deep indoor or underground situations even improved reception is inadequate for operation of positioning receivers, and possible solutions for this problem will be examined in this paper. Applications include tunnels, and perhaps shopping mall garages where vehicle navigation is highly desirable, even with reduced precision.

Izvorni jezik
Engleski

Znanstvena područja
Elektrotehnika

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