Drone Testing
AEROSPACETESTINGINTERNATIONAL.COM // DECEMBER 21
that can manipulate electromagnetic waves. Echodyne is
a four-year old startup based in the Seattle area backed
by Bill Gates and other investors.
The radar can detect a Cessna at three kilometers
and a small drone at nearly a kilometer. And then while
tracking a target, or as many as 15, it can scan
for other targets using multiple beams. The
1.25kg unit measures 20.3 x 16.3 x 4cm
and provides coverage of 120° in
azimuth and 80° in elevation.
Echodyne is marketing the ground
version for infrastructure security
applications. It has also developed a
smaller airborne version that can see
weather as well as aircraft.
Drones can also be equipped with
small ADS-B In receivers to detect any
manned aircraft broadcasting on ADS-B Out. Or
they can be equipped with ADS-B Out so the flight test
team on the ground can easily track the whereabouts of
the drones. These ADS-B components are becoming
smaller. Montana, USA-based startup uAvionix makes
ADS-B equipment the size of a US postage stamp, 63cm
thick. The miniaturization of drone avionics and sensors
is being driven in part by the military, which wants to
put increasingly advanced
capabilities on drones,
including electronic warfare
tasks. The founder of uAvionix
has lots of electronics
miniaturization experience from his
time as a chief technology at a Silicon Valley
chip manufacturer.
DRONE SENSING
Each drone expert interviewed for this article agreed
that an effective detect and avoid system in a UAV
requires more than one sensor and that there will be no
single solution.
“We know the FAA likes redundancy,” says Cathy
Cahill from UAF, who directed the research team that
conducted the recent BVLOS pipeline flight test. The test
team deployed eight Echodyne radars on the ground,
four of them owned by the university. Everybody knows
that safety is paramount and flight test organizations
cannot afford to have drones interfere with or collide
with manned aircraft if the BVLOS tests are to continue.
The drone in the pipeline test had to stay just 400ft
above the pipeline and flew up and down hills
maintaining the correct altitude. When it
took off at the start, the drone
immediately disappeared over the lip of
a ridge to follow the pipeline
descending a hillside. One additional
challenge of testing in Alaska is that
pilots often fly below 400ft and think
pipelines are something to follow. In
addition, pilots, such as hunters may also
choose to not turn ADS-B Out on when
they are scouting. According to Cahill, scud
running at low level below clouds is a problem
and is why a lot of accidents occur in Alaska. “Up here,
IFR stands for ‘I Follow Rivers’ not for ‘Instrument Flight
Rules’,” she says.
The university is also part of the FAA’s UAS Center
for Excellence program. The university’s Alaska Center
for Unmanned Aircraft Systems Integration (ACUASI),
which is run by Cahill, was also picked for a new FAA-led
1
project called the Integration Pilot
Program (IPP). The IPP was formed
in 2017 to help the FAA devise new
rules, policy and guidance for lowaltitude
UAV operations. ACUASI also
leads the Pan-Pacific UAS Test Range
Complex (PPUTRC), a partnership of test
ranges and experts in the USA, including
sites in Oregon and Hawaii also known as
the Pan-Pacific Partnership.
ALASKAN APPLICATIONS
Alaska has one of the greatest needs for
drone operations to take over hazardous
duty from manned aircraft in the USA.
As is the case elsewhere in the USA. there
is a pilot shortage in Alaska as older,
experienced pilots in the state retire. And
Cahill notes, every now and then Alaska
loses a pilot and a wildlife biologist on a
wildlife counting mission that could just
as easily be done by a drone – if only the
BVLOS problem is solved. The FAA has
not established rules and regulations yet
for BVLOS even though it allows a few
programs with waivers. Every test of
D&A technology and techniques in
Alaska and at the other FAA sites and
tests contribute data to understanding
what suite of sensors can do the job to
help drones avoid collisions.
The ultimate goal in Alaska that may
take a decade or more to solve is for
drones to serve remote villages with
deliveries rather than manned aircraft.
More than 80% of Alaska’s communities
can’t be reached by road and 169 of them
depend entirely on aircraft for the
delivery of goods and services. Many of
these communities are poor, but the cost
of air shipment on manned aircraft
means a gallon of milk costs US$12.
Jimmy Parrish, business director for
3km
maximum distance
at which an Echodyne
phased array radar can
detect a Cessna
95%
amount of time the
Iris Automation Casia
electro-optical sensor
spotted a Cessna
before a human eye
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