1 �� 0.8 m size with this explanation a grid step of 0.1 m). We do not focus on the performance of the descriptor but in the parameters of the filter to optimize the localization process. We test in a variety of environments, from small ones to larger ones, Inhibitors,Modulators,Libraries with a maximu
When a device wishes to determine its position, it does two things. First, the hardware uses an antenna and receiver to capture and record a location measurement. Second, the location measurement is converted into a global position in the form of longitude and latitude. Most often these two steps are conflated, and both are seen as necessary to enable location-based applications. In this paper we argue that for many security applications only the first step is needed: there is no need to accurately map the location measurement to an accurate global position.

Therefore, these location-based security applications can be implemented using a variety of radio frequency (RF) signals, including broadcast communication signals, such as AM/FM, cellular, DTV, Wi-Fi, etc., navigation signals, and an integration of various signals.While GPS provides accurate position data, other location services are far less accurate. Inhibitors,Modulators,Libraries LOng RAnge Navigation (Loran) [1], for example, uses a 3 km wavelength, and standalone Inhibitors,Modulators,Libraries Loran has an absolute accuracy of several hundred meters. Loran-C, the most recent version of Loran in use, is a terrestrial navigation system originally designed for naval applications and its operation is described in Appendix A. Its modernized version, called enhanced Inhibitors,Modulators,Libraries Loran (eLoran) [2], together with differential corrections can achieve an accuracy of 8 to 20 meters.

This paper uses standalone Loran-C, which has good repeatable accuracy, but low absolute accuracy, as a case study and shows that high absolute accuracy is not a requirement for a number of location-based Entinostat security applications. As with all radio-based systems, Loran-C radio signals are distorted by buildings and other objects, causing measurements to change greatly over short distances. Our main result shows that one can exploit these chaotic changes to obtain a precise and reproducible location tag with an accuracy of about 20 meters. Reproducibility means that selleck chemicals llc measurements at the same location at different times always produce the same tag. While there is no way to map location measurements to an accurate position, there are still many applications, primarily security applications, for which a reproducible and precise tag is sufficient.We build a reproducible and precise tag using recent results from biometric authentication for location-based security applications. In particular, we rely on fuzzy extractors [3,4] and secure sketches [5,6], originally designed for fingerprint-based authentication.