Inte
rnat
iona
l Sum
mer
Sch
ool f
or Io
nosp
heric
Phy
sics
, Eric
e, 2
4-29
Sep
tem
ber 2
004
R. L
eitin
ger,
Uni
v. G
raz,
I. o
f Phy
sics
, I. f
or G
eoph
ysic
s, A
stro
phys
ics
and
Met
eoro
logy
Tran
siono
sphe
ric p
ropa
gatio
n of
radi
o wa
ves
Plas
ma
effe
cts
on tr
ansi
onos
pher
icpr
opag
atio
n of
radi
o w
aves
Plas
ma
effe
cts
on
Plas
ma
effe
cts
on tr
ansi
onos
pher
ictr
ansi
onos
pher
icpr
opag
atio
n of
radi
o w
aves
prop
agat
ion
of ra
dio
wav
es
R. L
eitin
ger
Inte
rnat
iona
l Sum
mer
Sch
ool f
or Io
nosp
heric
Phy
sics
, Eric
e, 2
4-29
Sep
tem
ber 2
004
R. L
eitin
ger,
Uni
v. G
raz,
I. o
f Phy
sics
, I. f
or G
eoph
ysic
s, A
stro
phys
ics
and
Met
eoro
logy
Tran
siono
sphe
ric p
ropa
gatio
n of
radi
o wa
ves
•G
ener
al re
mar
ks
•R
emin
der o
n (tr
ansi
onos
pher
ic) w
ave
prop
agat
ion
•R
emin
der o
f pro
paga
tion
effe
cts
•G
PS a
s a
data
sou
rce
•So
me
elec
tron
con
tent
exa
mpl
es
Seco
nd le
ctur
e:
Mod
ern
appl
icat
ions
Inte
rnat
iona
l Sum
mer
Sch
ool f
or Io
nosp
heric
Phy
sics
, Eric
e, 2
4-29
Sep
tem
ber 2
004
R. L
eitin
ger,
Uni
v. G
raz,
I. o
f Phy
sics
, I. f
or G
eoph
ysic
s, A
stro
phys
ics
and
Met
eoro
logy
Tran
siono
sphe
ric p
ropa
gatio
n of
radi
o wa
ves
Gen
eral
rem
arks
We
have
two
type
s of
dat
a
•El
ectr
on c
onte
nt
•Sc
intil
latio
n pa
ram
eter
s
For s
cien
ce (g
eoph
ysic
s) th
e pr
opag
atio
n ef
fect
s ar
e ve
ry im
port
ant
data
sou
rces
,
for a
pplic
atio
ns th
ey a
re “
prop
agat
ion
erro
rs”
Inte
rnat
iona
l Sum
mer
Sch
ool f
or Io
nosp
heric
Phy
sics
, Eric
e, 2
4-29
Sep
tem
ber 2
004
R. L
eitin
ger,
Uni
v. G
raz,
I. o
f Phy
sics
, I. f
or G
eoph
ysic
s, A
stro
phys
ics
and
Met
eoro
logy
Tran
siono
sphe
ric p
ropa
gatio
n of
radi
o wa
ves
Wav
es, w
ave
prop
agat
ion
The
sim
ples
t mat
hem
atic
al m
odel
for a
wav
e is
a C
osin
e fu
nctio
n:u
= U
cos
[ 2 π
( x / λ
– f
t ) ]
= U
cos
[ 2 π
f ( x
/ v
– t )
] =
U c
os [ ϕ
]U
: am
plitu
de,
ϕ : p
hase
λ: w
ave
leng
th,
f: f
requ
ency
,x:
spa
tial c
oord
inat
e,
t: t
ime.
Con
stan
t U :
plan
ar w
ave
with
no
atte
nuat
ion,
pro
paga
tion
velo
city
v
= f λ
( p
hase
vel
ocity
)pr
opag
atio
n in
the
dire
ctio
n of
x.
Com
paris
on o
f v
with
a c
onst
ant
c g
ives
the
refr
activ
e in
dex
n =
c / v
.El
ectro
mag
netic
wav
es:
c is
the
free
spac
e ve
loci
ty o
f lig
ht
Inte
rnat
iona
l Sum
mer
Sch
ool f
or Io
nosp
heric
Phy
sics
, Eric
e, 2
4-29
Sep
tem
ber 2
004
R. L
eitin
ger,
Uni
v. G
raz,
I. o
f Phy
sics
, I. f
or G
eoph
ysic
s, A
stro
phys
ics
and
Met
eoro
logy
Tran
siono
sphe
ric p
ropa
gatio
n of
radi
o wa
ves
The
conc
ept o
f pla
nar w
aves
is n
ot re
alis
tic.
In g
ener
al s
pher
ical
wav
es w
hich
orig
inat
e at
a c
entra
l poi
nt o
r
conv
erge
into
a c
entra
l poi
nt a
re a
bet
ter c
once
pt.
r:
dis
tanc
e fro
m th
e ce
ntra
l poi
nt.
In
cosi
ne a
rgum
ent (
“pha
se”)
repl
ace
x b
y r
Am
plitu
de: r
epla
ce U
by
Uo (
r o /
r)
(„ge
omet
ric d
ilutio
n“).
Inte
rnat
iona
l Sum
mer
Sch
ool f
or Io
nosp
heric
Phy
sics
, Eric
e, 2
4-29
Sep
tem
ber 2
004
R. L
eitin
ger,
Uni
v. G
raz,
I. o
f Phy
sics
, I. f
or G
eoph
ysic
s, A
stro
phys
ics
and
Met
eoro
logy
Tran
siono
sphe
ric p
ropa
gatio
n of
radi
o wa
ves
The
refr
activ
e in
dex
desc
ribes
the
prop
ertie
s of
the
prop
agat
ion
med
ium
.It
also
con
tain
s th
e in
fluen
ce o
f w
ave
abso
rptio
n (lo
ss o
f wav
e en
ergy
).In
nat
ural
med
ia (e
.g.,
plan
etar
y at
mos
pher
es,
iono
sphe
res,
ther
mal
plas
ma
in th
e su
rroun
ding
s of
bod
ies
of th
e so
lar s
yste
m ,
inin
terp
lane
tary
spa
ce, e
tc.,
the
refr
activ
e in
dice
s ar
esp
ace
(and
tim
e) d
epen
dent
(inh
omog
eneo
us p
ropa
gatio
n co
nditi
ons)
.If
the
refr
activ
e in
dex
depe
nds
on fr
eque
ncy
we
have
dis
pers
ion,
ifth
ey d
epen
d on
the
dire
ctio
n of
pro
paga
tion
we
have
ani
sotr
opy.
Inte
rnat
iona
l. Su
mm
er S
choo
l for
Iono
sphe
ric P
hysi
cs, E
rice,
24-
29 S
epte
mbe
r 200
4
R. L
eitin
ger,
Uni
v. G
raz,
I. o
f Phy
sics
, I. f
or G
eoph
ysic
s, A
stro
phys
ics
and
Met
eoro
logy
Tran
siono
sphe
ric p
ropa
gatio
n of
radi
o wa
ves
We
shou
ld d
istin
guis
h be
twee
n th
e re
gula
rly la
yere
d st
ruct
ure
of th
em
ediu
m (i
n ca
se o
f the
atm
osph
ere
of th
e Ea
rth w
e as
sum
e ho
rizon
tal
scal
es in
the
orde
r of m
agni
tude
of a
few
100
km
), su
perp
osed
sm
alle
rsc
ale
stru
ctur
es (e
.g.,
wav
elik
e on
es, t
roug
hs, r
idge
s, e
tc.),
and
sm
all
scal
e irr
egul
ariti
es.
The
regu
larly
laye
red
stru
ctur
e gi
ves
amon
g ot
her e
ffect
s co
ntin
uous
refra
ctio
n an
d ph
ase
shift
, the
sm
all s
cale
fluc
tuat
ions
are
resp
onsi
ble
for
“sci
ntilla
tions
" of s
igna
l par
amet
ers,
esp
ecia
lly o
f am
plitu
de a
nd p
hase
.
We
have
to c
ompa
re s
truct
ure
scal
e(s)
with
wav
e le
ngth
.
Inte
rnat
iona
l. Su
mm
er S
choo
l for
Iono
sphe
ric P
hysi
cs, E
rice,
24-
29 S
epte
mbe
r 200
4
R. L
eitin
ger,
Uni
v. G
raz,
I. o
f Phy
sics
, I. f
or G
eoph
ysic
s, A
stro
phys
ics
and
Met
eoro
logy
Tran
siono
sphe
ric p
ropa
gatio
n of
radi
o wa
ves
The
atm
osph
ere
(neu
tral
gas
and
pla
sma)
influ
ence
s al
l sig
nal
para
met
ers,
like
am
plitu
de, p
hase
, ang
le o
f arr
ival
, etc
.R
egul
ar la
yerin
g: re
frac
tion
(ray
ben
ding
), ph
ases
hift,
ang
le o
f arr
ival
cha
nge,
etc
.
(sm
all s
cale
) Irr
egul
ariti
es: s
catte
ring
(irre
gula
r [„s
toch
astic
“] flu
ctua
tions
of (
all)
sign
alpa
ram
eter
s
„Sc
intil
latio
ns“ (
if th
ere
is a
n [a
ppar
ent]
rela
tive
mov
emen
t bet
wee
n ra
ypa
th a
nd ir
regu
larit
ies)
Inte
rnat
iona
l Sum
mer
Sch
ool f
or Io
nosp
heric
Phy
sics
, Eric
e, 2
4-29
Sep
tem
ber 2
004
R. L
eitin
ger,
Uni
v. G
raz,
I. o
f Phy
sics
, I. f
or G
eoph
ysic
s, A
stro
phys
ics
and
Met
eoro
logy
Tran
siono
sphe
ric p
ropa
gatio
n of
radi
o wa
ves
Ref
ract
ion
(Sne
ll´s
law
):
n 1 si
n α
= n
2 sin
β …
(dis
cret
e la
yers
)
n s
in α
= c
onst
.(c
ontin
uous
)α
Inte
rnat
iona
l Sum
mer
Sch
ool f
or Io
nosp
heric
Phy
sics
, Eric
e, 2
4-29
Sep
tem
ber 2
004
R. L
eitin
ger,
Uni
v. G
raz,
I. o
f Phy
sics
, I. f
or G
eoph
ysic
s, A
stro
phys
ics
and
Met
eoro
logy
Tran
siono
sphe
ric p
ropa
gatio
n of
radi
o wa
ves
Inte
rnat
iona
l Sum
mer
Sch
ool f
or Io
nosp
heric
Phy
sics
, Eric
e, 2
4-29
Sep
tem
ber 2
004
R. L
eitin
ger,
Uni
v. G
raz,
I. o
f Phy
sics
, I. f
or G
eoph
ysic
s, A
stro
phys
ics
and
Met
eoro
logy
Tran
siono
sphe
ric p
ropa
gatio
n of
radi
o wa
ves
Inte
rnat
iona
l Sum
mer
Sch
ool f
or Io
nosp
heric
Phy
sics
, Eric
e, 2
4-29
Sep
tem
ber 2
004
R. L
eitin
ger,
Uni
v. G
raz,
I. o
f Phy
sics
, I. f
or G
eoph
ysic
s, A
stro
phys
ics
and
Met
eoro
logy
Tran
siono
sphe
ric p
ropa
gatio
n of
radi
o wa
ves
Inte
rnat
iona
l Sum
mer
Sch
ool f
or Io
nosp
heric
Phy
sics
, Eric
e, 2
4-29
Sep
tem
ber 2
004
R. L
eitin
ger,
Uni
v. G
raz,
I. o
f Phy
sics
, I. f
or G
eoph
ysic
s, A
stro
phys
ics
and
Met
eoro
logy
Tran
siono
sphe
ric p
ropa
gatio
n of
radi
o wa
ves
Inte
rnat
iona
l Sum
mer
Sch
ool f
or Io
nosp
heric
Phy
sics
, Eric
e, 2
4-29
Sep
tem
ber 2
004
R. L
eitin
ger,
Uni
v. G
raz,
I. o
f Phy
sics
, I. f
or G
eoph
ysic
s, A
stro
phys
ics
and
Met
eoro
logy
Tran
siono
sphe
ric p
ropa
gatio
n of
radi
o wa
ves
Inte
rnat
iona
l Sum
mer
Sch
ool f
or Io
nosp
heric
Phy
sics
, Eric
e, 2
4-29
Sep
tem
ber 2
004
R. L
eitin
ger,
Uni
v. G
raz,
I. o
f Phy
sics
, I. f
or G
eoph
ysic
s, A
stro
phys
ics
and
Met
eoro
logy
Tran
siono
sphe
ric p
ropa
gatio
n of
radi
o wa
ves
Inte
rnat
iona
l Sum
mer
Sch
ool f
or Io
nosp
heric
Phy
sics
, Eric
e, 2
4-29
Sep
tem
ber 2
004
R. L
eitin
ger,
Uni
v. G
raz,
I. o
f Phy
sics
, I. f
or G
eoph
ysic
s, A
stro
phys
ics
and
Met
eoro
logy
Tran
siono
sphe
ric p
ropa
gatio
n of
radi
o wa
ves
Inte
rnat
iona
l Sum
mer
Sch
ool f
or Io
nosp
heric
Phy
sics
, Eric
e, 2
4-29
Sep
tem
ber 2
004
R. L
eitin
ger,
Uni
v. G
raz,
I. o
f Phy
sics
, I. f
or G
eoph
ysic
s, A
stro
phys
ics
and
Met
eoro
logy
Tran
siono
sphe
ric p
ropa
gatio
n of
radi
o wa
ves
Inte
rnat
iona
l Sum
mer
Sch
ool f
or Io
nosp
heric
Phy
sics
, Eric
e, 2
4-29
Sep
tem
ber 2
004
R. L
eitin
ger,
Uni
v. G
raz,
I. o
f Phy
sics
, I. f
or G
eoph
ysic
s, A
stro
phys
ics
and
Met
eoro
logy
Tran
siono
sphe
ric p
ropa
gatio
n of
radi
o wa
ves
Inte
rnat
iona
l Sum
mer
Sch
ool f
or Io
nosp
heric
Phy
sics
, Eric
e, 2
4-29
Sep
tem
ber 2
004
R. L
eitin
ger,
Uni
v. G
raz,
I. o
f Phy
sics
, I. f
or G
eoph
ysic
s, A
stro
phys
ics
and
Met
eoro
logy
Tran
siono
sphe
ric p
ropa
gatio
n of
radi
o wa
ves
Inte
rnat
iona
l Sum
mer
Sch
ool f
or Io
nosp
heric
Phy
sics
, Eric
e, 2
4-29
Sep
tem
ber 2
004
R. L
eitin
ger,
Uni
v. G
raz,
I. o
f Phy
sics
, I. f
or G
eoph
ysic
s, A
stro
phys
ics
and
Met
eoro
logy
Tran
siono
sphe
ric p
ropa
gatio
n of
radi
o wa
ves
GPS
as
a da
ta s
ourc
eTh
e “c
lass
ical
” TEC
sou
rces
pro
vide
dor
fixe
d ge
omet
ry a
nd h
igh
tem
pora
l res
olut
ion
(GEO
Far
aday
bea
cons
)or
nea
rly c
onst
ant L
ocal
Tim
e an
d hi
gh s
patia
l (la
titud
inal
) res
olut
ion
(LEO
Diff
.D
oppl
er b
eaco
ns)
true
sign
al a
mpl
itude
and
pha
seG
PS (M
EO o
rbit;
12
hour
per
iod,
incl
inat
ion
53 d
egre
es)
mix
es te
mpo
ral a
nd s
patia
l dep
ende
nce
(diu
rnal
cur
ves
of T
EC fo
r a g
iven
loca
tion
are
alw
ays
com
posi
tes,
etc
.)N
eeds
com
plic
ated
“cal
ibra
tion”
pro
cedu
res
(CO
DE
= G
roup
Del
ay n
eeds
kno
wle
dge
of tr
ansm
itter
and
rece
iver
del
ays
and
cann
otpr
ovid
e su
ffici
ent r
esol
utio
n fo
r sci
ence
app
licat
ions
, PH
ASE
= D
iff. D
oppl
er s
uffe
rsfro
m 2
am
bigu
ity
CO
DE
and
PHAS
E co
mbi
natio
n ne
eded
for a
ll sc
ienc
eap
plic
atio
ns)
Am
plitu
de a
nd p
hase
are
“re
cons
truc
ted”
in th
e re
ceiv
erTh
eref
ore:
TEC
map
ping
, ada
ptiv
e m
odel
ling,
dat
a in
gest
ion
into
mod
els,
…
Inte
rnat
iona
l Sum
mer
Sch
ool f
or Io
nosp
heric
Phy
sics
, Eric
e, 2
4-29
Sep
tem
ber 2
004
R. L
eitin
ger,
Uni
v. G
raz,
I. o
f Phy
sics
, I. f
or G
eoph
ysic
s, A
stro
phys
ics
and
Met
eoro
logy
Tran
siono
sphe
ric p
ropa
gatio
n of
radi
o wa
ves
Diu
rnal
cur
ves
of io
nosp
heric
ele
ctro
n co
nten
t in
units
of
1015
m-2
der
ived
from
the
Fara
day
effe
ct o
n th
e 13
7M
Hz
beac
on o
f the
geo
stat
iona
ry s
atel
lite
SIR
IO (a
tab
out 6
5°E)
. Rec
eivi
ng s
tatio
n G
raz,
Aus
tria
(47.
1°N
,15
.5°E
). Io
nosp
heric
poi
nt (4
00 k
m):
42.2
°N, 2
5.0°
E).
Cro
sses
: act
ual e
lect
ron
cont
ent o
f Oct
ober
5, 1
984,
age
omag
netic
ally
qui
et d
ay (A
p=7)
. Unm
arke
d cu
rves
from
bot
tom
to to
p: m
inim
a, lo
wer
qua
rtile
s, m
edan
s,up
per q
uarti
les,
max
ima
for O
ctob
er, 1
984,
a lo
w s
olar
activ
ity m
onth
(mon
thly
mea
n su
nspo
t num
ber R
=12,
mon
thly
mea
n 10
.7cm
sol
ar ra
dio
flux:
73.
5 un
its).
Absc
issa
: zon
al ti
me
15°E
(=U
T +
1 ho
ur).
Inte
rnat
iona
l Sum
mer
Sch
ool f
or Io
nosp
heric
Phy
sics
, Eric
e, 2
4-29
Sep
tem
ber 2
004
R. L
eitin
ger,
Uni
v. G
raz,
I. o
f Phy
sics
, I. f
or G
eoph
ysic
s, A
stro
phys
ics
and
Met
eoro
logy
Tran
siono
sphe
ric p
ropa
gatio
n of
radi
o wa
ves
Exam
ple
for F
arad
ay o
bser
vatio
ns o
n th
e si
gnal
s of
the
geos
tatio
nary
sat
ellit
e SI
RIO
mad
e at
the
Fire
nze
field
stat
ion
Mor
telic
cio
(dot
s; o
ne d
atum
per
min
ute)
and
Gra
z(c
ross
es; h
ourly
val
ues)
. TEC
in u
nits
of 1
015 m
− 2 v
s.U
nive
rsal
Tim
e in
hou
rs. D
iurn
al c
urve
; day
to d
ayva
riatio
ns; s
ome
TID
act
ivity
.
Inte
rnat
iona
l Sum
mer
Sch
ool f
or Io
nosp
heric
Phy
sics
, Eric
e, 2
4-29
Sep
tem
ber 2
004
R. L
eitin
ger,
Uni
v. G
raz,
I. o
f Phy
sics
, I. f
or G
eoph
ysic
s, A
stro
phys
ics
and
Met
eoro
logy
Tran
siono
sphe
ric p
ropa
gatio
n of
radi
o wa
ves
Exam
ple
for F
arad
ay o
bser
vatio
ns o
n th
e si
gnal
s of
the
geos
tatio
nary
sat
ellit
e M
ETEO
SAT-
2 m
ade
at F
irenz
e on
25 a
nd 2
6 M
ay, 1
991.
TEC
in u
nits
of 1
015 m
− 2 v
s.U
nive
rsal
Tim
e in
hou
rs. D
iurn
al c
urve
; str
ong
day
toda
y va
riatio
ns; v
ery
stro
ng T
ID a
ctiv
ity o
n 25
May
.
Inte
rnat
iona
l Sum
mer
Sch
ool f
or Io
nosp
heric
Phy
sics
, Eric
e, 2
4-29
Sep
tem
ber 2
004
R. L
eitin
ger,
Uni
v. G
raz,
I. o
f Phy
sics
, I. f
or G
eoph
ysic
s, A
stro
phys
ics
and
Met
eoro
logy
Tran
siono
sphe
ric p
ropa
gatio
n of
radi
o wa
ves
Exam
ple
for a
str
ong
posi
tive
stor
m e
ffect
in io
nosp
heric
ele
ctro
n co
nten
t: Su
dden
Com
men
cem
ent o
f the
geo
mag
netic
stor
m (S
SC) o
n 4
Febr
urar
y, 1
983,
16:
15 U
T, D
st-m
inim
a: -1
59 n
T on
4 F
eb.,
20 U
T, -1
69 n
T on
5 F
eb.,
11 U
T. F
arad
ay e
ffect
on g
eost
atio
nary
sat
ellit
e si
gnal
rece
ived
at H
amilt
on, M
A, U
SA (4
00 k
m io
nosp
h. p
oint
: 39°
N, 2
89°E
; geo
mag
n. la
t. 50
°).
Ord
inat
e: e
lect
ron
cont
ent i
n un
its o
f 1015
m− 2
, abs
ciss
a: U
nive
rsal
Tim
e (U
T). 3
Feb
ruar
y; q
uiet
refe
renc
e da
y (A
p=7)
.In
term
edia
te le
vel o
f sol
ar a
ctiv
ity (m
onth
ly m
ean
suns
pot n
umbe
r R=5
1).
Inte
rnat
iona
l Sum
mer
Sch
ool f
or Io
nosp
heric
Phy
sics
, Eric
e, 2
4-29
Sep
tem
ber 2
004
R. L
eitin
ger,
Uni
v. G
raz,
I. o
f Phy
sics
, I. f
or G
eoph
ysic
s, A
stro
phys
ics
and
Met
eoro
logy
Tran
siono
sphe
ric p
ropa
gatio
n of
radi
o wa
ves
Exam
ple
for a
str
ong
nega
tive
stor
m e
ffect
in io
nosp
heric
ele
ctro
n co
nten
t: Su
dden
Com
men
cem
ent o
f the
geo
mag
netic
stor
m (S
SC) o
n 11
Apr
il, 1
981,
13:
39 U
T, D
st-m
inim
a: -1
67 n
T on
12
April
, 6 U
T, -2
91 n
T on
13
April
, 7 U
T. F
arad
ay e
ffect
on
geos
tatio
nary
sat
ellit
e si
gnal
rece
ived
at M
adrid
, Spa
in (4
00 k
m io
nosp
h. p
oint
: 37°
N, -
4°E;
geo
mag
n. la
t. 41
°). O
rdin
ate:
elec
tron
cont
ent i
n un
its o
f 1015
m− 2
, abs
ciss
a: U
nive
rsal
Tim
e (U
T). 1
1 Ap
ril w
as a
slig
htly
dis
turb
ed d
ay (A
p=39
). Th
e ne
gativ
est
orm
effe
ct w
as p
rono
unce
d in
the
long
itude
zon
e ar
ound
0° o
nly.
Hig
h so
lar a
ctiv
ity (m
onth
ly m
ean
R=1
56).
Inte
rnat
iona
l Sum
mer
Sch
ool f
or Io
nosp
heric
Phy
sics
, Eric
e, 2
4-29
Sep
tem
ber 2
004
R. L
eitin
ger,
Uni
v. G
raz,
I. o
f Phy
sics
, I. f
or G
eoph
ysic
s, A
stro
phys
ics
and
Met
eoro
logy
Tran
siono
sphe
ric p
ropa
gatio
n of
radi
o wa
ves
Com
paris
on o
f pea
k el
ectro
n de
nsity
Nm
from
foF2
with
ele
ctro
n co
nten
t fro
m F
arad
ay o
bser
vatio
nsm
ade
at G
raz
on th
e VH
F be
acon
of S
IRIO
(lat
itude
of th
e io
noph
eric
poi
nt: 4
2.5°
N).
Dat
a fro
m 1
981.
Mon
thly
qua
ntile
s (lo
wer
dec
iles,
low
er q
uarti
les,
med
ians
, upp
er q
uarti
les,
upp
er d
ecile
s) fo
r 0 L
Tan
d 12
LT.
Inte
rnat
iona
l Sum
mer
Sch
ool f
or Io
nosp
heric
Phy
sics
, Eric
e, 2
4-29
Sep
tem
ber 2
004
R. L
eitin
ger,
Uni
v. G
raz,
I. o
f Phy
sics
, I. f
or G
eoph
ysic
s, A
stro
phys
ics
and
Met
eoro
logy
Tran
siono
sphe
ric p
ropa
gatio
n of
radi
o wa
ves
Annu
al v
aria
tion
of e
quiv
alen
t sla
b th
ickn
ess
for 1
981
from
the
com
bina
tion
of v
ertic
al e
lect
ron
cont
ent (
TEC
)m
easu
red
by m
eans
of t
he F
arad
ay e
ffect
on
the
VHF
sign
al o
f SIR
IO re
ceiv
ed a
t Gra
z (la
titud
e of
iono
sphe
ricpo
int:
42.5
°N) a
nd p
eak
elec
tron
dens
ity N
m fr
om th
eio
noso
nde
data
of R
oma
(41.
9°N
, 12.
5°E)
. Upp
er p
anel
:0L
T, lo
wer
pan
el: 1
2 LT
Inte
rnat
iona
l Sum
mer
Sch
ool f
or Io
nosp
heric
Phy
sics
, Eric
e, 2
4-29
Sep
tem
ber 2
004
R. L
eitin
ger,
Uni
v. G
raz,
I. o
f Phy
sics
, I. f
or G
eoph
ysic
s, A
stro
phys
ics
and
Met
eoro
logy
Tran
siono
sphe
ric p
ropa
gatio
n of
radi
o wa
ves
Exam
ple
for l
atitu
dina
l pro
files
of v
ertic
al e
lect
ron
cont
ent f
rom
NN
SS o
bser
vatio
ns m
ade
at G
raz
dem
onst
ratin
g th
e po
tent
ial
of c
ombi
ned
obse
rvat
ions
for t
imes
of h
igh
sola
r act
ivity
. Dat
aof
1 N
ovem
ber,
1990
. Ele
ctro
n co
nten
t in
units
of 1
015 m
− 2 v
s.ge
ogr,
latit
ude
in d
eg. N
(N to
S).
Upp
er p
anel
: tra
ces
of th
eio
nosp
heric
poi
nts
(in 4
00 k
m h
eigh
t) in
a g
eogr
aphi
c sy
stem
.Ev
en fo
r mid
latit
udes
the
equa
toria
l ano
mal
y is
impo
rtan
t!
Inte
rnat
iona
l Sum
mer
Sch
ool f
or Io
nosp
heric
Phy
sics
, Eric
e, 2
4-29
Sep
tem
ber 2
004
R. L
eitin
ger,
Uni
v. G
raz,
I. o
f Phy
sics
, I. f
or G
eoph
ysic
s, A
stro
phys
ics
and
Met
eoro
logy
Tran
siono
sphe
ric p
ropa
gatio
n of
radi
o wa
ves
Exam
ple
for l
atitu
dina
l pro
files
of v
ertic
al e
lect
ron
cont
ent f
rom
NN
SS o
bser
vatio
ns m
ade
at G
raz
dem
onst
ratin
g th
e po
tent
ial
of c
ombi
ned
obse
rvat
ions
for t
imes
of h
igh
sola
r act
ivity
.Af
tern
oon/
even
ing
of 2
Nov
embe
r, 19
90. E
lect
ron
cont
ent i
nun
its o
f 1015
m− 2
vs.
geo
gr, l
atitu
de in
deg
. N (N
to S
). U
pper
pane
l: tra
ces
of th
e io
nosp
heric
poi
nts
(in 4
00 k
m h
eigh
t) in
age
ogra
phic
sys
tem
. In
the
early
eve
ning
the
effe
ct o
f the
equa
toria
l ano
mal
y is
eve
n m
ore
pron
ounc
ed!
Inte
rnat
iona
l Sum
mer
Sch
ool f
or Io
nosp
heric
Phy
sics
, Eric
e, 2
4-29
Sep
tem
ber 2
004
R. L
eitin
ger,
Uni
v. G
raz,
I. o
f Phy
sics
, I. f
or G
eoph
ysic
s, A
stro
phys
ics
and
Met
eoro
logy
Tran
siono
sphe
ric p
ropa
gatio
n of
radi
o wa
ves
Latit
ude
depe
nden
ce o
f TEC
from
Diff
. Dop
pler
on
the
150/
400
MH
z si
gnal
s of
NN
SS. R
ecei
ving
sta
tions
Gra
z(4
7.1°
N, 1
5.5°
E) a
nd U
ppsa
la (5
9.8°
N, 1
7.6°
E). T
ypic
aleq
ujin
ox/w
inte
r nig
ht p
rofil
e. M
ain
troug
h w
ith m
inim
umar
ound
60°
N. I
ndic
atio
n of
TEC
incr
ease
tow
ards
the
equa
toria
l ano
mal
y in
the
Sout
h. 1
8 O
ctob
er, 1
989
arou
nd 2
1:10
UT.
TEC
in u
nits
of 1
015 m
− 2 v
s ge
ogra
phic
latit
ude.
Upp
er p
anel
: tra
ces
of th
e io
nosp
heric
poi
nts
(in40
0 km
hei
ght)
in a
geo
grap
hic
syst
em. H
igh
sola
r act
ivity
(mon
thly
mea
n R
=159
, mon
thly
mea
n 10
.7 c
m s
olar
radi
oflu
x: 2
09 u
nits
).
Inte
rnat
iona
l Sum
mer
Sch
ool f
or Io
nosp
heric
Phy
sics
, Eric
e, 2
4-29
Sep
tem
ber 2
004
R. L
eitin
ger,
Uni
v. G
raz,
I. o
f Phy
sics
, I. f
or G
eoph
ysic
s, A
stro
phys
ics
and
Met
eoro
logy
Tran
siono
sphe
ric p
ropa
gatio
n of
radi
o wa
ves
Latit
ude
depe
nden
ce o
f TEC
from
Diff
. Dop
pler
on
the
150
/ 400
MH
z si
gnal
s of
NN
SS. R
ecei
ving
sta
tion
Dio
nyso
s (3
8.1°
N,
23.0
°E) a
nd U
ppsa
la (5
9.8°
N, 1
7.6°
E). T
EC in
uni
ts o
f 1016
m− 2
vs
geog
raph
ic la
titud
e. 8
Apr
il, 1
981,
aro
und
11:4
0 U
T.M
onth
ly m
ean
R=1
56, m
onth
ly m
ean
10.7
cm
sol
ar ra
dio
flux:
223
uni
ts).
Geo
mag
netic
ally
nea
rly q
uiet
(Ap=
11).
Very
hig
h va
lues
of
TEC
Inte
rnat
iona
l Sum
mer
Sch
ool f
or Io
nosp
heric
Phy
sics
, Eric
e, 2
4-29
Sep
tem
ber 2
004
R. L
eitin
ger,
Uni
v. G
raz,
I. o
f Phy
sics
, I. f
or G
eoph
ysic
s, A
stro
phys
ics
and
Met
eoro
logy
Tran
siono
sphe
ric p
ropa
gatio
n of
radi
o wa
ves
Exam
ple
for l
atitu
dina
l pro
files
of v
ertic
al e
lect
ron
cont
ent f
rom
NN
SS o
bser
vatio
ns m
ade
from
the
stat
ions
GIB
ilman
na,
L’A
QU
ila, G
RA
z an
d LI
Nda
u. F
ebru
ary
21, 1
995,
aro
und
03:1
9 U
T (to
p) a
nd 0
7:00
UT
(bot
tom
). El
ectro
n co
nten
t in
units
of 1
015 m
− 2 v
s. g
eogr
, lat
itude
in d
eg. N
(N to
S).
The
exam
ple
in th
e to
p sh
ows
a m
idla
titud
e m
axim
um o
f ele
ctro
nco
nten
t, po
ssib
ly th
e si
gnat
ure
of a
“nig
httim
e in
crea
se”.
The
min
imum
of t
he m
ain
troug
h is
not
see
n be
caus
e of
a c
ut o
ff in
the
data
from
Lin
dau.
It is
indi
cate
d in
the
botto
m e
xam
ple.
The
max
imum
has
now
flat
tene
d ou
t.
Com
bina
tion
of F
arad
ayw
ith D
iff. D
oppl
erda
ta.R
ecei
ving
sta
tions
Gra
z (4
7.1°
N, 1
5,5°
E)an
d Li
ndau
/Har
z (5
1.6°
N,
10.1
°E).
Con
tour
line
s of
vTEC
in u
nits
of 1
015 m
− 2
in a
geo
grap
hic
latit
ude
vs. l
ocal
tim
e sy
stem
. 10,
11, 1
2 an
d 13
Dec
embe
r,19
75. L
ow s
olar
act
ivity
(mon
thly
mea
n 10
.7 c
mso
lar r
adio
flux
: 75
units
),ge
omag
netic
ally
qui
et(A
p=8,
5, 3
, 3).
Geo
stat
iona
ry s
atel
lite
ATS-
6 an
d N
NSS
.
Inte
rnat
iona
l Sum
mer
Sch
ool f
or Io
nosp
heric
Phy
sics
, Eric
e, 2
4-29
Sep
tem
ber 2
004
R. L
eitin
ger,
Uni
v. G
raz,
I. o
f Phy
sics
, I. f
or G
eoph
ysic
s, A
stro
phys
ics
and
Met
eoro
logy
Tran
siono
sphe
ric p
ropa
gatio
n of
radi
o wa
ves
Than
k yo
u fo
r you
r atte
ntio
n Th
ank
you
for y
our a
ttent
ion
––
part
part
II II fo
llow
s to
mor
row
follo
ws
tom
orro
w
Inte
rnat
iona
l Sum
mer
Sch
ool f
or Io
nosp
heric
Phy
sics
, Eric
e, 2
4-29
Sep
tem
ber 2
004
R. L
eitin
ger,
Uni
v. G
raz,
I. o
f Phy
sics
, I. f
or G
eoph
ysic
s, A
stro
phys
ics
and
Met
eoro
logy
Tran
siono
sphe
ric p
ropa
gatio
n of
radi
o wa
ves
