AVTIS - stacking the data
Who are we?
The workshop and exhibition
Resources and information
St Andrews <

Imaging <
The Basics

Applications <
The Universe
Brijot Imager
Car Radar
Debris Detection
Aircraft Landing
External links
Photo gallery

In this section:

> 1. Intro
> 2. The Instrument
> 3. The Antenna
> 4. As a Radar
> 5. Seeing the Volcano
> 6. Measuring
> 7. Data Stacking
> 8. A Scan
> 9. Colour Code
> 10. The Volcano
> 11. Pyroclastic Flows
> 12. Devastation
> 13. The Future

Once the beam has been scanned across the lava dome a map of the reflections can be made by colouring the strength of the radar reflections in the range spectrum. The reflections in the radar slice then trace out a contour line across the mountainside. Repeating this process pointing at different heights, AVTIS builds up a stack of slices each with a slightly different contour line.

All of the contour lines contained within this stack of data can then be turned into a 3D surface inside the computer giving an accurate measurement of the lava dome shape. The picture below shows the 3D surface reconstructed by AVTIS from a scan over the bottom part of the lava dome on Montserrat.

You can clearly see where the older part of the dome bulges out on the right hand side. Notice also how the radar can see straight through the steam belching from the flanks of the volcano in the picture. Steam, gas and ash are all made up of tiny particles, much smaller than a millimetre in size, so the mm-waves pass through and the bounce off of the surface of the volcano instead.

'Vision For The Future' is an EPSRC funded project run by the MMW group at the University of St Andrews
Copyright ©2006 by the University of St Andrews :: web, graphic and exhibition design by FifeX Ltd, www.fifex.co.uk