change historic landscape software tools laser intensity cropmarks germany spain associated partner tara geopyhsics caa relief visualization vegetation removal digital elevation model dem roman germanic commission geophysics dtm aerial survey fli map 400 research infrared light europe digital surface model special interest group partner open source interpretation global positioning system gis hillforts roman glauberg italy landscape laser beam cultural heritage management inertial measurement unit resistance 3 dimensional model lidar survey relief mapping etruscan aerial photography remote sensing airborne laser scanning topographic survey german archaeological institute iron age micro topography resilience dam discovery programme digital terrain model archaeology historic environment ireland visualization high resolution conference culture 2007 aargnews northern ireland princely sites three dimnesional ground resolution dsm eu workshop 3d lidar methods