GPS and GPR
GPS and GPR (Ground Penetrating Radar) measurements on the coastline

Links
- https://www.ifgeo.uni-bonn.de/en/sections/geophysics/news/geophysikalische-messungen-auf-der-nordseeinsel-spiekeroog/spieker4.jpg/image_view_fullscreen
- https://www.ifgeo.uni-bonn.de/en/sections/geophysics/news/geophysikalische-messungen-auf-der-nordseeinsel-spiekeroog/spieker4.jpg/@@download/image/spieker4.jpg