Data from three continuously operating GPS sites located in the interior of the Greenland ice sheet are analyzed. Traditionally these kinds of GPS installations (where the GPS antenna is placed on a pole deployed into the firn) are used to estimate the local horizontal speed and direction of the ice sheet. However, these data are also sensitive to the vertical displacement of the pole as it mov...

Among the available technologies such as cables and lasers, the Global Positioning System (GPS) is being increasingly used for automated continuous monitoring of landslides and avalanches. The timely identification of precursory movements of landslides could save lives and minimise collateral damage. Carrier-phase observations from four or more GPS satellites allow relative displacements to be ...

Having combined the advantages of ground-based interferometric radar and Global Position System (GPS), a microwave radar with transponder for three-dimensional displacement monitoring method has been proposed. In this system, the active reflector ensures the long measurement distance at low antenna radiation power; the transponder provides the total solutions to antenna microwave leakage and mu...

In order to estimate the speed of a moving vehicle with side view camera images, velocity vectors of a sufficient number of reference points identified on the vehicle must be found using frame images. This procedure involves two main steps. In the first step, a sufficient number of points from the vehicle is selected, and these points must be accurately tracked on at least two successive video ...

Precise orbit determination (POD) of low earth orbiters (LEOs) with GPS is becoming a standard practice in the space science community. The need for such information has been growing rapidly due to such scientific applications as radio occultation and ever increasing demands from engineering applications such as spacebased earth sensor positioning. The conventional GPSbased POD strategies rely ...