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From YouTube: Space and Satellite Symposium 2021 Courtney Duncan
Description
Space and Satellite Symposium Courtney Duncan N5BF "Amateur Radio as Testbed"
A
For
many
radio
amateurs,
the
communications
technology
is
not
just
a
black
box
for
some
in
purpose.
Hams
are
interested
in
all
aspects
of
the
technology
itself,
from
power
sources
to
digital
control
and
processing
systems,
to
mixing
and
amplification
to
electromagnetic
transducers,
that
is
antennas
to
electromagnetic
fields
and
their
propagation
properties.
A
Amateur
radio
is
a
non-commercial
by
definition,
but
radio
amateurs
are
licensed
to
operate
on
a
broad
range
of
different
bands
from
a
few
hundred
kilohertz
to
microwaves
to
lasers
and
are
therefore
exposed
to
broad
spectrum
of
variation
in
propagation
equipment
and
usage.
It's
worth
pointing
out
that
this
is
relatively
unique
within
the
practice
of
radio.
If
ram
radio
amateurs
want
to
create
a
satellite
based
communication
system
with
uplinks
in
their
5.8
gigahertz
and
downlinks
in
their
10
gigahertz
bands
or
any
of
the
other
mini
bands
authorized
for
amateur
satellite
use.
A
The
process
of
licensing
and
coordinating
is
relatively
straightforward.
Amateurs
can
and
have
put
satellites
on
seven
megahertz
29
megahertz,
144
megahertz
and
1.26
gigahertz.
For
example,
amateur
radio
contains
many
diverse
sub-communities
and
therefore
styles
and
motivations
of
operation
and
experimentation
among
the
experimenters.
A
It
is
usually
more
important
to
develop
approaches
and
technologies
that
work
over
challenging
and
challenging
is
usually
defined
as
long
distance
paths
at
all,
rather
than
deliver
a
certain
volume
of
low
latency
bandwidth
for
revenue.
This
allows
for
trials
sub,
optimization
and
even
failures,
lending
leading
to
improvements
without
the
risk
of
commercially
unacceptable
consequences.
A
Even
though
one
of
many
features
of
amateur
radio
is
low,
bandwidth,
unreliable
communication
to
destinations
chosen
largely
at
random
by,
for
instance,
the
propagation
medium,
even
these
properties
have
led
to
some
interesting
and
useful
capabilities,
which
are
often
picked
up
by
the
broader
communication
community
in
favor
of
the
amateur
approach
to
technology
development.
Is
this
great
diversity
of
purpose
and
the
variability
to
take
long
shot
risks?
A
Historically,
radio
amateurs
have
used
modulation
techniques
to
send
information
by
voice
and
morse
code
using
on
off
keying
the
technology
pioneered
in
the
19th
century,
when
all
the
brains
of
a
communication
system
were
the
human
brains
involved.
Amateurs
refer
to
this
use
of
on
off
keying
as
cw
for
a
continuous
wave.
A
These
nominally
fit
into
bandwidths
of
about
three
kilohertz
and
and
400
hertz,
respectively,
where
the
lower
bandwidth
cw
link
can
be
closed
with
10
to
15
db.
More
reliability
are
equivalently
5
to
7
db,
more
distance
other
things
being
the
same
at
the
cost
of
10
to
15
db
of
reduced
information
rate.
A
Amateurs
who
attempt
this
over
the
most
challenging
paths
are
called
weak
signal
operators
because
they're
trying
to
recover
information
from
a
low
or
marginal
signal
to
noise
ratio.
In
a
clear
in
a
cleverly
devised
machine,
brain
collaboration,
at
the
dawn
of
the
21st
century,
a
team
of
software
developers
led
by
nobel
laureate
joe
taylor,
k1jt
begin
development
of
a
set
of
modulation
techniques
tailored
to
a
certain
amateur
radio
communication
situation
that
uses
the
popular
three
kilohertz
bandwidth
channels,
supported
by
lots
of
amateur
equipment,
to
much
greater
effectiveness
by
subdividing.
A
A
The
station
can
be
and
is
used
for
direct
communication
line
of
sight
with
other
stations
in
the
region,
but
its
design
intent
is
to
transmit
signals
focused
on
the
moon,
have
them
scattered
by
the
moon
and
detect
the
weak
signal
returns
back
on
earth,
a
process
that
a
23
centimeter
wavelength
suffers
about.
291
db
of
loss.
A
A
station
like
this
is
just
barely
able
to
work
in
other,
just
like
it
with
difficulty
on
cw
low
bandwidth,
morse
code
with
a
skilled
operator
voice.
Communication
is
only
possible
when
partnered
with
another
much
larger
station,
such
as
a
10
meter
dish
running
a
thousand
watts
using
the
k1
jt
digital
modes.
However,
I'm
able
to
easily
work
those
stations
plus
others
that
are
much
smaller
down
to
around
1
meter
dish
or
equivalent
yagi's
in
size
and
100
watts.
A
A
Perhaps
another
10
db
or
more
successful
contacts
currently
take
a
few
minutes
to
a
few
tens
of
minutes
when
they
get
to
where
they
take
a
few
hours.
Other
limitations,
not
just
the
physics
of
radio
itself,
will
apply
within
the
confines
of
the
requirements
of
weak
signal
radio
operators.
Astounding
progress
has
been
made
in
optimizing,
very
powerful
modulations
codes
and
protocols
for
information
recovery.
A
The
stereotype
of
amateur
radio
is
that
it
is
mostly
shortwave
that
is
wavelengths
of
tens
of
meters
and
antennas
of
corresponding
size,
as
these
waves
are
refracted
back
to
earth
by
the
ionosphere
worldwide
communication.
Yes,
that
is
unreliable.
Low
bandwidth
to
destinations
chosen
largely
at
random,
is
supported
under
some
conditions,
which
are
analyzed
and
predicted
thoroughly,
just
like
the
weather,
a
shorter
wavelengths,
just
above
the
short
waves
up
to
about
a
thousand
megahertz
amateurs,
have
our
share
allocations
in
the
highly
popular
vhf
and
uhf
regions
that
are
used
for
local,
near
line
of
sight,
communication.
A
A
Sometimes
hams
are
the
professionals
who
are
implementing
systems
for
very
exciting
applications,
such
as
the
recent
mars
helicopter
ingenuity,
which
is
partnered
with
the
latest
mars
rover
perseverance
doing
the
investigations
on
mars.
Right
now,
due
to
the
very
thin
air
on
mars,
the
helicopter
had
to
be
as
light
as
possible,
and
the
designers
would
have
liked
nothing
better
than
a
communication
system
that
had
zero
mass
as
it
was.
We
were
able
to
deliver
a
system
at
13.3
grams,
which
was
acceptable
and
had
a
target
operating
range
of
up
to
one
kilometer.
A
So
here's
the
60
dollar
zigbee
part
used
on
both
ingenuity
and
perseverance
to
implement
the
communication
link,
it's
a
small
system
on
a
module
that
weighs
3.3
grams
on
earth.
After
we
were
finished
modifying
it,
the
proprietary
offshoot
of
zigbee
was
implemented
in
the
part
family
as
delivered,
and
this
is
a
one
watt,
914
megahertz
psalm,
with
the
capability
for
diversity,
reception.
A
Requirements
such
as
the
need
for
the
helicopter
to
maintain
radio
silence
and
for
the
rover
base
station
to
control
the
link
at
all
times,
the
physical
layer
was
not
modified.
All
transmissions
are
single
packets
with
their
own
synchronization
and
they
have
payloads
up
to
about
a
thousand
bits.
Each.
A
A
Although
you
can
see
here
that
some
of
the
parts
would
do
better
than
that
at
some
temperatures,
also,
the
ability
to
use
retries
increases
the
recovery
rate
near
the
cliffs
of
the
performance
edges.
This
information
was
used
along
with
data
about
the
terrain
and
relative
vehicle
orientations,
with
respect
to
the
antennas
to
predict
and
analyze
link
performance
on
mars.
A
A
A
The
parameter
of
interest
to
me
is
the
green
line
at
the
bottom,
which
maps
directly
into
received
signal
level.
You
can
see
the
signal
improved
when
the
helicopter
is
airborne,
varying
as
it
flies
along
through
the
rover,
antenna,
azimuth
pattern,
sometimes
changing
orientation
itself
and
then
going
going
back
down
on
landing
to
a
slightly
lower
level
at
its
new
ground
location.
A
This
flight
path
was
630
meters
over
hazardous
terrain
and
the
beginning
and
ending
points
were
several
hundred
meters
from
the
rover.
The
landed
signal
level
shows
here
is
about
minus
85
dbm,
which
leaves
about
10
db
margin
at
the
data
rate
being
used.
The
blue
line
is
the
one
of
interest
to
the
customer.
A
The
amount
of
data
transferred
per
unit
time
in-flight
telemetry
is
throttled
to
about
55
kilobits
per
second,
so
as
not
to
bump
the
limits
of
the
80
kilobit
per
second
effective
throughput
link,
but
you
can
see
peaks
near
that
level
in
the
file
transfers.
At
the
end,
the
orange
line
is
a
link
quality
indicator
which
is
not
particularly
meaningful
in
this
particular
mode,
but
no
data
was
dropped,
lost
skipped
or
necked
in
this
session
and
just
for
fun.
This
is
one
of
my
favorite
aerial
photos
from
the
helicopter
mission.
A
A
A
Not
only
was
an
impressive
task
accomplished
with
an
inexpensive
off-the-shelf
part
and
protocol,
but
it
was
extended
and
amended
as
appropriate
to
the
task
at
hand
by
engineers
who
had
first-hand
knowledge
of
practical
ways
to
achieve
the
goal
to
radio
amateurs.
A
communication
system
is
not
a
mathematical
abstraction.
A
It
is
a
visceral
reality
for
which
they
have
well-developed
seat
of
the
pants
instincts
engineers
with
extensive
amateur
radio.
Avocational
experience
were
chosen
for
this
particular
job.
For
that
reason,
so,
looking
forward
into
the
large
larger,
worldwide
telecommunications,
community
and
industry,
amateur
radio
continues
to
make
significant
contributions
and
remains
relevant
into
the
second
century.
A
It's
also
necessary
for
us,
like
all
science
and
technology
developers,
to
get
the
word
out
there
by
publishing
and
participating
in
conferences
like
this,
and,
of
course,
we
must
all
cooperate
and
coordinate
with
each
other
within
the
avocation
to
keep
it
relevant
and
vibrant
hams
are
busy
doing
all
these
things.
As
we
speak.