Articles in the Positioning Category

Jan 2012 | No Comment

GPS was offi cially declared to have achieved full operational capability (FOC) on July 17, 1995, ensuring the availability of at least 24 operational, non-experimental, GPS satellites. To meet the future requirements, the GPS decision makers have studied several options to adequately modify the signal structure and system architecture of the future GPS constellation. The modernization program aims to, among other things, provide signal redundancy and improve positioning accuracy, signal availability, and system integrity (El- Rabbany 2006 ). Unfortunately, even with the modernized system, there exist situations where the GPS signal may be partially obstructed, e.g. in urban canyons, which in turn affect the availability and reliability of the PPP solution

Oct 2011 | No Comment

Positioning with GPS can be realized two main ways: i-Single Point Positioning (SPP), ii- relative positioning. When the high accuracy is required, the accuracy obtained from SPP is not enough and for those applications relative positioning method have to be considered. However in this method, there should be at least two receivers to collect the data and software to process these data.

Aug 2011 | No Comment

This paper is going to provide a concept of a new system for positioning the target bees. The biologists eagerly wish to collect the bodies of the bees in order to find the causes of the colony collapse disorder (CCD) of bees. As we know it, there are several ways used to find out and trace animals. For example, the scientists set up the transponders or the GPS trackers on the top of shells of thalassians or on the feet of migrant birds by ringing. These methods make great contributions for tracking and studying in the field of the biological research. However, how to track or position small insects, like cicadas, butterflies, or bees, is still a problem needed to be solved. The obvious crux of the problem is the size and the weight of the devices which are not suitable for fitting on such a small insects.

May 2011 | No Comment

Li-Ta Hsu, Wen-Ming Tsai and Shau-Shiun Jan
This section conducts the static and dynamic experiments of the indoor positioning algorithms mentioned above, and these results are used to find the best indoor positioning algorithm for the RTIPS. To implement the indoor positioning tests, the classroom 5834 of the DAA building of NCKU is chosen as the experiment place. In this paper, the fingerprinting method based on the RSS is utilized to estimate the user location.

Mar 2011 | One Comment

The year 1978 saw the launch of the first Global Positioning System (GPS) satellite. Today, GPS, as the first and currently only operational global navigation satellite system (GNSS), is widely used and is a vital technology for many of society’s economic, scientific and social activities. Applications can be found everywhere, such as spacecraft navigation, geodesy, surveying and mapping, precision navigation, machine guidance, vehicle fleet management and “intelligent transport systems” (ITS), emergency services and “location based services” (LBS). Clearly the development of GPS has revolutionised what are now termed “positioning, navigation and timing” (PNT) activities.

Feb 2011 | No Comment

Around the transit area between the indoor and outdoor environments of buildings, it is anticipated that the number of available measurements may not be sufficient for localization and the undesirable non-line-of-sight (NLOS) and multipath errors would severely deteriorate the localization accuracy. To estimate user location reliably where measurements from global positioning system (GPS) receivers are corrupted or not available, network-based methods have been actively investigated.

Feb 2011 | No Comment

Nowadays, a growing number of GNSS users demand highly-accurate positioning with minimal latency. PPP is a new positioning technique providing centimeter-level error. Precise Point Positioning (PPP) processes measurements from a single user receiver, using detailed physical models and corrections, and precise GNSS orbit and clock products computed beforehand.

Jan 2011 | No Comment

GPS receivers are able to be employed in the survey field as low cost sensors or for applications where it is necessary to have a good ratio between cost and benefits. Nowadays, there are several low cost GPS receivers able to provide both pseudorange and carrier phase measurements in the L1band, that allow to have good real-time performances in outdoor condition. The present paper describes a set of dedicated tests in order to evaluate the positioning accuracy in static conditions.

Jan 2011 | No Comment

A very interesting feature of the transmitter approach is the possibility to locate transmitters underneath the receiver. The transmitter-based approach is an indoor positioning method, based on the use of a local infrastructure, aiming to provide accuracies of 1 to 2 meters. The GNSS signals are received by an outdoor antenna located in a place with an unobstructed view of the satellites. Note that another possibility is to use a GNSS signal generator (generating one or 4 satellites) instead of the outdoor antenna.

Oct 2010 | No Comment

The Arctic ice is receding at a faster pace than expected a few years ago, and is quickly opening for increased human activities beyond the Arctic Circle (66.56° N). This drives a growing demand for navigation in the Arctic area, which is mainly composed of marine expanses and the land masses of Norway, Iceland, Greenland (Denmark), Northern Canada, Alaska (USA), and the Northern parts of Russia…