Due to limited receiver bandwidth and tracking configuration differences, measurements made on a narrowband geostationary satellite signal may differ significantly from those made on GPS signals and result in relatively large range bias errors for users. Modeling and analysis of this net effect is complicated by several parameters including a wide range of allowed GEO signal correlator spacings...

The residual range delay error due to an incompletely modelled tropospheric propagation delay can usually be ignored by the average user of wide-area differential GPS. In general the atmosphere is “well behaved” and the use of standard range delay algorithms supplied with standard atmosphere parameter values will adequately model the “average” atmospheric conditions. It is possible however, for...

Autonomous fixed-wing UAV landing based on differential GPS is now a mainstream providing reliable and precise landing. But the task still remains challenging when GPS aviability is limited like for military UAV’s. We discuss a solution of this problem based on computer vision and dot markings along stationary or makeshift runway. We focus our attempts on using infrared beacons along with narro...

The ocean wave signatures within conventional noncoherent marine X-band radar (MR) image sequences can be used to derive near-surface current information. On ships, an accurate near-real-time record of the near-surface current could improve navigational safety. It could also advance understanding of air–sea interaction processes. The standard shipboard MR near-surface current estimates were fou...

This paper presents current and future uses of Differential Satellite Navigation Systems in Sierra Research’s Automatic Flight Inspection Systems (AFIS). The purpose of an Automatic Flight Inspection System is to inspect and calibrate ground-based aircraft navigation and landing aids. In Sierra’s inertial-based flight inspection system, a square root Kalman filter estimates the navigation error...

Georeferenced high-resolution satellite images can be used for acquisition of topographic information, navigation and visualisation for various environmental studies. The present study is part of the multidisciplinary EU project GEOWARN related to monitoring, warning and emergency planning for volcanic hazards in the island of Nisyros, Greece. Here, the main aim was the orthorectification of a ...

The application of custom classification techniques and posterior probability modeling (PPM) using Worldview-2 multispectral imagery to archaeological field survey is presented in this paper. Research is focused on the identification of Neolithic felsite stone tool workshops in the North Mavine region of the Shetland Islands in Northern Scotland. Sample data from known workshops surveyed using ...

This paper investigates the use of semantic information to link ground-level occupancy maps and aerial images. A ground-level semantic map is obtained by a mobile robot equipped with an omnidirectional camera, differential GPS and a laser range finder. The mobile robot uses a virtual sensor for building detection (based on omnidirectional images) to compute the ground-level semantic map, which ...

A 1.227 GHz low power single-ended input, differential output low noise amplifier (balun LNA) for GPS is proposed. A two stage structure with current-reused technique is adopted to achieve low power, low noise factor and high voltage gain simultaneously. The LNA is fabricated in 0.18 mm CMOS process, consuming only 2 mA current from a 1.8 V supply. The LNA is measured to exhibit a differential ...