The Global Positioning System (GPS) signals are very weak signal over wireless channels, so they are vulnerable to in-band interferences. Therefore, even a low-power interference can easily spoof GPS receivers. Among the variety of GPS signal interference, spoofing is considered as the most dangerous intentional interference. The spoofing effects can mitigate with an appropriate strategy in the...

Estimates of ambulance travel times on road networks are critical for effective ambulance base placement and real-time ambulance dispatching. We introduce new methods for estimating the distribution of travel times on each road segment in a city, using Global Positioning System (GPS) data recorded during ambulance trips. Our preferred method uses a Bayesian model of the ambulance trips and GPS ...

In a previous study we developed an elegant technique to compute the signal travel time delay due to the neutral atmosphere, also known as slant total delay (STD), between a Global Positioning System (GPS) satellite and a ground-based receiver utilizing data from a numerical weather model (NWM). Currently, we make use of NWM data from the Global Forecast System (GFS) because short-range forecas...

excessive cutting depth during leveling of agricultural land increases power needed by the tractor drawbar and will result in undesirable slippage and excessive strain on the tractor engine.  the result of sustained excess will be the break-down of the tractor. an auxiliary blade depth controller to prevent overloading during leveling was designed, fabricated and evaluated in this study. the sy...

In present study, using Least Squares (LS) method, we determine the position smoothing in GPS single-frequency receiver by means of pseudo-range and carrier phase measurements. The application of pseudo-range or carrier phase measurements in GPS receiver positioning separately can lead to defects. By means of pseudo-range data, we have position with less precision and more distortion. By use of...

This paper describes about the modeling of errors (like ionospheric delays, atmospheric delays, Troposphericelays, Multipath effects and dilution of precision etc.,) affecting the GPS signals as they travel from satellite to user on Earth. These errors degrade the accuracy of GPS position. An attempt is made to improve the accuracy in locating the GPS receiver by filtering the range measurement...

variable rate application (vra) based on site specific crop management (sscm) is an effective approach for optimizing the application of agricultural inputs and preventing the undesirable environmental impacts. design, construction and evaluation of a map-based vra system was the main objective followed in this research. for variable rate application based on the generated map, a direct injecti...