Deformation monitoring

Navigation Gps Use

GPS is now used in all aspects of navigation GPS voice navigation systems are standard with many models of car Simply typing the required destination into the unit results in a graphical display of the route , along with voiced directions 

Similar systems are used by private boats as digital charts and by aeroplanes, whilst handheld receivers are now standard equipment for many walkers and cyclists 

GPS has many applications for sports monitoring and provides the spatial and time element of the data for sports performance analysis 

GPS enabled wristwatches and mobile phones have been available for several years now 

GPS is used in fleet management for determining the vehicles positions and status so that they can be transmitted to a central control thereby permitting better management of the assets 

At the individual vehicle level the driver can use GPS as an aid to destination and route location 

GPS is used by surveying ships for major offishore hydrographic surveys 

Ocean going liners use it for navigation purposes , whilst most harbours have a DGPS system to enable precise docking 

Even recreational craft rely on it almost to the exclusion of traditional methods of navigation and pilotage 

At the present time , aircraft lading and navigation are controlled by a variety of disparate systems 

GPS is well used and may eventually provide a single system for all aircraft operations 

The uses to which GPS can be put are limited only by the imagination of the user 

They can range from the complexities of measuring tectonic movement to the simplicity of spreading fertilizer in precision farming and include many areas of scientific study , such as meteorology , oceanography , and geophysics 

As satellite systems continue to develop the applications will continue to grow 

The advantage of using GPS is that it enables near real  - time monitoring for deformation if data recorded and processed online

There are a number of such projects currently operational and are described at their respective websites 

Examples include monitoring by Nottingham University of the number Bridge and a bridge in Nottingham for movement 

natural disasters such as landslides volcanoes and earthquakes

Although GPS can give three dimensional time tagged positions at the rate of 10 - 20 Hz this means that oscillations of more than half this value cannot be easily detected 

Since information about actual vibration is of use to engineers the output of other technologies such as accelerometers may be incorporated with that of GPS through mathematical techniques like Kalman filtering 

Kalman filtering is a predictor corrector process that enables solutions of position and velocity of greater precision than those obtainable with either GPS or the accelrometers alone 

The GPS based online Control and System ( GOCA ) developed at Fachochschule Karlsruhe University of Applied Sciences , Germany , can be used for the online monitoring of movements associated with , and preceding , natural disasters such as landslides , volcanoes and earthquakes 

The system may be entirely GPS based or use total stations as well as in Figure 9.29 

The system can also be used to monitor safety critical movement of buildings or dams 

The online modelling of a classical deformation network loads to the computation and visualization of time series data of individual receivers 

With filtering and analysis of the data it is possible to detect movements that are significant , but much smaller than the precision of individual GPS measurements 

These movements may trigger an automatic alarm and give warning of an impending disaster