Page 61 - World Airnews Magazine June 2020 Edition

NEWS DIGITAL

“This flooding potentially threatens a bridge that is
connected to the road system,” Wolken said. “And this is
the only road that would connect residents on the north
side to hospitals and other vital facilities, so if this bridge
was impacted it would cause some very serious issues for
a lot of people.”
In addition to helicopter-based photogrammetry,
Wolken and his team have conducted LIDAR surveys with
manned aircraft and have also used quad copters.
But when Wolken learned about WingtraOne during
a fellowship in Davos, he saw a solution that suited the
broad coverage these basin surveys demand and offered
the possibility of more frequent data capture missions.
The helicopter surveys they had been conducting cost
around 3500 USD and were only possible annually. The
nature of this study requires more frequent surveys of
the area to recognize elevation change patterns that
indicate water filling the basin under the glacier that is
responsible for the downstream flooding.
“We also used a Phantom 4 to do some of the photo-
grammetry, but it required a lot of effort to survey the
lake, with several battery changes just to cover the area,”
Wolken said.

"NO COMPARISON" IN TERMS OF SAFETY AND
EFFORT
In addition to the efficiency factor, anyone native to this
environment is well aware of the risk to those collecting
data in the basin, with aircraft or manually.
“This is an amazingly challenging terrain in which to
work. It’s so complex, with so many challenging wind
vectors that make it dangerous to be in an aircraft in this
area,” Wolken explained. “So simply staying out of an
aircraft is the greatest advance in safety that we could
have in this setting - it’s really important.”
WingtraOne takes the research another step forward
because of its well-integrated multi-frequency PPK
module. This enables high levels of location (absolute)
accuracy without the need for extensive ground control.
“On the ground, in terms of the workflow, absolutely,
compared to the other drones that we used in this
project, WingtraOne was really a game-changer in terms
of the amount of time that we saved by only having to
collect a handful of checkpoints to provide validation for
analyses.” Q

ALASKA-SIZED COVERAGE MEETS HIGH ACCURACY
Wolken and his team flew with the WingtraOne PPK and
RX1R II bundle to survey Suicide Basin at the time of year
when the water level peaks. He was more than pleased
with the resolution and accuracy of the data gathered,
especially considering the terrain and coverage.
“Alaska is a big place. There’s virtually nothing we
address that we consider small here. So if it’s going to be
a drone, we have to have something that can actually fly
for a long time, fly high enough to be able to handle the
complex terrain that we’re constantly dealing with and
provide the resolution that’s required for the analyses
that we’re doing. WingtraOne does this.”
For a single mission with 3 cm (1.2 in) / px GSD, cov-
ering 3 km2, it took 90 minutes from start to finish. The
1734 images stitched together provided an orthophoto
and a digital terrain model that the team used to analyze
levels and track changes over multiple missions.

World Airnews | June Extra 2020
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