Using
Non‐Specular
Radar
Meteor
Echoes
to

Monitor
Lower
Thermosphere
Wind
Profiles‐

ABSTRACT

We
present
a
new
method
of
measuring
 lower
thermospheric
wind
velocity
profiles

by
 tracking
 non‐specular
 meteor
 echoes
 in
 Ame.
 This
 approach
 relies
 on
 having
 a

radar
 following
plasma
 irregulariAes
as
 they
are
dragged
by
 the
neutral
wind.
 
 This

requires
 a
 VHF
 radar
 with
 interferometric
 capability
 able
 to
 point
 close
 to

perpendicular
 to
 the
 geomagneAc
 field.
 
 Using
 a
 small
 sample
 of
 data
 from
 the

Jicamarca
Radio
Observatory,
we
calculated
wind
speeds
and
direcAons
between
90

and
110\,
km
with
a
range
resoluAon
of
a
few
hundred
meters.
 
The
measurements

taken
show
speeds
reaching
150m/s
and
someAmes
changing
by
as
much
as
100m/s

over
a
6km
alAtude
range.
With
some
refinement
of
the
data
collecAon
and
analysis

techniques,
 we
 expect
 that
 one
 could
 obtain
 high
 resoluAon
 images
 of
 lower

thermospheric
winds
as
they
change
in
both
alAtude
and
Ame.

We
will
discuss
these

results,
the
physics
underlying
these
measurements,
and
the
limitaAons.

Meers
Oppenheim1,
Glenn
Sugar1,

Elizabeth
Bass1,
Nick
Slowey1,
Jorge
Chau2
and
Sigrid
Close3

1
Center
for
Space
Physics,
Boston
University;
2:
Radio
Observatorio
de
Jicamarca
InsAtuto
Geofisico
del
Peru;
3:
Los
Alamos
NaAonal
Laboratories

Acknowledgments.
Work
was
supported
by
NaAonal
Science
FoundaAon
grants
ATM‐9986976,
ATM‐0332354,

ATM‐0334906,
ATM‐0432565,
and
DGE‐0221680
and
DOE
grant
DEFG02‐06ER54887.
The
authors
would
like
to

thank
the
JRO
(and
IGP)
staff
for
performing
the
observaAons,
parAcularly
F.
Galindo
for
help
processing
the

data,
as
well
as
M.
Mendillo,
D.
Hysell,
and
M.
Nicolls
for
useful
suggesAons.

Legend:


Red:
0‐0.5s


Blue:
10‐10.5s

Sample
Meteor
Echo

CapAon:
Long
trail
from
July
12,
’05
data
set.
 The
SNR
(leg)
in
dB
and
the
phase

difference
(right)
between
the
B
and
C
quarters
of
the
antenna
array

CapAon:
East‐west
and
north‐south
trail
posiAons
vs.
alAtude
at
0s–0.5s
(red)
and

again
at
10s–10.5s
(blue).
Phase
data
in
these
intervals
were
treated
as
staAsAcal

samples
and
converted
to
3‐D
posiAons.
The
central
point
at
alAtude
corresponds
to

the
mean
posiAon,
while
the
horizontal
bars
give
the
standard
deviaAon.

Using

trail
phase
differences
to
obtain
meteor
echo
posiAons
at
0.25s
and
10s

CapAon:
Difference
between
the
B

and
C
phase
angles
in
radians
at

96
km
alAtude.

Specular
Meteor
Radar
Winds

Buckland
Park
VHF
Meteor
Radar

New
Wind
Velocity
Profiles

Not to scale 
80 km 
130 km 
A

B

C

Rocket
Wind
Speeds

Larsen,
M.
F.
,
J.
Geophys.
Res.,
2002

Phase
differences
in
each
range
gate
has
a
disAnct
slope:
Gives
the
wind
speed

Determining
Winds
from
HPLA
data:
An
example