ABSTRACT.A Digital Elevation Model (DEM) is a digital representation of ground surface topography or terrain with different accuracies for different application fields. DEM have been applied to a wide range of civil engineering and military planning tasks. DEM is obtained using a number of techniques such as photogrammetry, digitizing, laser scanning, radar interferometry, classical survey and GPS techniques. This paper presents an assessment study of DEM using GPS (Stop&Go) and kinematic techniques comparing with classical survey. The results show that a DEM generated from (Stop&Go) GPS technique has the highest accuracy with a RMS error of 9.70 cm. The RMS error of DEM derived by kinematic GPS is 12.00 cm.

A method is presented for calculation of the ultrasonic from NXN ultrasound phased array transducers to treat cancer in liver using hyperthermia treatment The analysis uses the bioheat transfer equation with tissue properties to get the temperature distribution. The synthesize method consists of simultaneously focusing of the ultrasound beam at different points uniformly distributed along the tumor periphery. It is demonstrates that by combining the multiple focusing features with the Esoudo inverse method and the new field phasing concept, typical undesired hot spots can be eliminated Temperature distribution associated with two methods will be simulated and discussed.

1) assistan professor,radiology department ,faculty of medicine fayoum university.(2) lecturer,radiology department,faculty of medicine ,fayoum university.(3) Master degree