PHOTOGRAMMETRIC ENGINEERING & REMOTE SENSING
May 2020
265
FEATURE
B
ackground
The island of Alderney, a British crown possession
with its own government located 8 miles off the coast
of France in the Channel Islands, was once home to
a German SS concentration camp. Caroline Sturdy
Colls, a professor of Conflict Archaeology and Genocide
Investigation at Staffordshire University in the UK,
travelled with her team to the island to investigate the
camp as it was the only camp on British soil.
The investigation and the surprising results were the
subject of a documentary ‘Adolf Island’ produced by the
Smithsonian Channel. The documentary showcased
Routescene’s 3D mapping capability and demonstrated
how lidar technology is currently being used in fields
such as archaeology and forensics to create a bare earth
model that identifies structures without disturbing
protected land.
According to the documentary, the Nazis took over the
island because they had plans to invade Britain. They
used 4,000 slave laborers on Alderney to build a defence
system that included gun batteries, bunkers, tunnels and
massive fortifications.
Most of the structures were destroyed by the Germans
after they surrendered and the number of people who
were killed on the island remains a mystery. There
are 336 Russian prisoners buried in a cemetery, but
survivors claim that many more were killed.
However, the Alderney government prevented Professor
Sturdy Colls’ team from doing any excavation so she
sought the assistance of UAV lidar technology which uses
pulsed laser light to measure ranges to the ground under
the vegetation canopy.
R
econstruct
WWII C
oncentration
C
amp
under
H
eavy
C
anopy with
UAV L
idar
Gert Riemersma, CTO, Routescene
Professor Sturdy Colls contacted Routescene’s customer
and frequent collaborator, Flythru, to conduct a UAV
lidar survey of the sites at Alderney. Lager Sylt, the
concentration camp built and run by the SS, and Longis
Common, a graveyard, were chosen based on records
from a German War Graves Commission investigation
from 1960.
The task was to investigate the sites primarily focusing
on an area believed to contain mass graves adjacent
to the current airport runway. Stringent restrictions
placed by local residents and authorities prevented the
archaeologists from breaking ground and it was only very
reluctantly that permission was given for a non-intrusive
aerial survey.
The surveyed area was overgrown with meter-high
grasses, heathers and scrub and it was apparent from
initial photogrammetry that the RGB imagery (although
useful) was insufficient to fully establish where the
structures of the camp had been.
It was not until the UAV lidar system was used and
the data examined that the full extent of the camp and
surrounding features could be identified and located.
The use of UAV lidar allowed penetration of the dense
vegetation and enabled the team to reconstruct the
layout of the concentration camp.
Photogrammetric Engineering & Remote Sensing
Vol. 86, No. 5, May 2020, pp. 265–267.
0099-1112/20/265–267
© 2020 American Society for Photogrammetry
and Remote Sensing
doi: 10.14358/PERS.86.5.265
