ILR

S W

orks

hop

2003

, Oct

ober

28-3

1, 2

003,

Köt

ztin

g, G

erm

any

The

Spec

ial R

ole

of S

LR fo

rIn

ter-

Tech

niqu

eC

ombi

natio

ns

Mar

kus

Rot

hach

erFo

rsch

ungs

einr

icht

ung

Sat

ellit

enge

odäs

ie, T

U M

ünch

en(F

ES

G)

ILR

S W

orks

hop

2003

Oct

ober

28-3

1, 2

003

Koe

tztin

g, G

erm

any

ILR

S W

orks

hop

2003

, Oct

ober

28-3

1, 2

003,

Köt

ztin

g, G

erm

any

•In

trodu

ctio

n

•S

&S

:So

lutio

ns a

nd S

tatis

tics

•W

&W

:W

avel

engt

h an

d W

ater

Vap

or

•C

&C

:C

lock

s an

d C

orre

latio

ns

•A

&A

:A

nten

nas

and

Abs

olut

e S

cale

•G

&G

:G

eom

etry

and

Gra

vity

•O

&O

:O

rbits

and

“O-C

”

•C

oncl

usio

ns

Con

tent

ILR

S W

orks

hop

2003

, Oct

ober

28-3

1, 2

003,

Köt

ztin

g, G

erm

any

Intr

oduc

tion:

Vis

ion

of a

Rig

orou

s C

ombi

natio

n

•M

ake

use

of th

e st

reng

ths

of th

e in

divi

dual

ob

serv

atio

n te

chni

ques

•P

rofit

from

co-

loca

tion

of in

stru

men

ts

(site

s an

d sa

telli

tes)

•E

nsur

e co

nsis

tenc

ybe

twee

n al

l te

chni

ques

•D

iffer

bet

wee

n te

chni

que-

spec

ific

syst

emat

ic b

iase

san

d ge

nuin

e ge

odet

ic/g

eoph

ysic

al s

igna

ls

•Fi

nal g

oal:

All

com

mon

par

amet

ers

of a

ll ob

serv

ing

tech

niqu

es a

re ri

goro

usly

co

mbi

ned

as c

onsi

sten

t inp

ut to

the

IGG

OS

pr

ojec

t

ILR

S W

orks

hop

2003

, Oct

ober

28-3

1, 2

003,

Köt

ztin

g, G

erm

any

Para

met

er S

pace

forC

ombi

natio

n

Para

met

er T

ype

VL

BI

GPS

/G

LO

N.

DO

RIS

/PR

AR

ESL

RL

LR

Alti

-m

etry

Qua

sar C

oord

. (IC

RF)

XN

utat

ion

X(X

)X

Pola

r Mot

ion

XX

XX

XU

T1X

Leng

thof

Day

(LO

D)

XX

XX

Sub-

Dai

lyER

PsX

XER

P O

cean

Tid

eA

mpl

itude

sX

XX

X

Coo

rd.+

Vel

oc.(I

TRF)

XX

XX

X(X

)G

eoce

nter

X

XX

XG

ravi

tyFi

eld

XX

X(X

)X

Orb

itsX

XX

XX

LEO

Orb

itsX

XX

XIo

nosp

here

XX

XX

Trop

osph

ere

XX

XX

Tim

e/Fr

eq. T

rans

fer

(X)

X(X

)

Major SLR Contributions

(X)

ILR

S W

orks

hop

2003

, Oct

ober

28-3

1, 2

003,

Köt

ztin

g, G

erm

any

Solu

tions

and

Stat

istic

s(S

&S)

CO

NT‘

02SL

R

VLB

I G

PS

# O

bs.

5’19

546

’682

5’93

5’76

0 #

Coo

rd.

8124

459

# E

OP

75

7575

#

Trop

os.

01’

554

26’7

26

# O

rbits

30

03’

770

# A

mbi

g.

00

43’2

38

# C

lock

s 0

1’16

4--

- #

Par

am.

186

2’81

774

’268

CO

NT‘

02 V

LBI C

ampa

ign

•D

GFI

: VLB

Isol

utio

ns•

TUM

: G

PSso

lutio

ns•

TUM

: SL

Rso

lutio

ns(L

1+L2

)

Oct

ober

17-3

0, 2

003,

con

tinuo

usV

LBI

SLR

: few

obse

rvat

ions

buta

lso

few

para

met

ers

(no

cloc

ks, n

o tro

posp

here

, no

ambi

guiti

es,…

)

ILR

S W

orks

hop

2003

, Oct

ober

28-3

1, 2

003,

Köt

ztin

g, G

erm

any

Wav

elen

gth

and

Wat

erVa

por(

W&

W)

SLR

is th

e on

ly te

chni

que

obse

rvin

g at

opt

ical

wav

elen

gths

:

•S

LR is

in a

uni

que

situ

atio

nco

ncer

ning

atm

osph

eric

refra

ctio

n•

Trop

osph

ere

disp

ersi

vefo

r SLR

, but

not

for m

icro

wav

es•

Two-

frequ

ency

lase

r ran

ging

(mai

nly

valid

atio

n to

ol ?

)•

Dry

del

ay c

an b

e m

odel

ed w

ith p

ress

ure

data

at t

he s

ite•

Wet

del

ay is

qui

te s

mal

l

All

othe

r tec

hniq

ues

(GPS

, VLB

I, D

OR

IS, a

ltim

etry

, InS

AR

, …):

•S

uffe

r fro

m th

e sa

me

trop

osph

eric

refr

actio

n ef

fect

s•

Suf

fer f

rom

sim

ilar i

onos

pher

icre

frac

tion

effe

cts

•H

ave

tropo

sphe

ricre

fract

ion

as th

e or

a m

ajor

err

or s

ourc

e

Onl

y SL

R c

an h

elp

to d

etec

t bia

ses

(e.g

. due

to a

tmos

pher

e m

ism

odel

ing)

com

mon

to a

ll ot

her t

echn

ique

s

ILR

S W

orks

hop

2003

, Oct

ober

28-3

1, 2

003,

Köt

ztin

g, G

erm

any

Wav

elen

gth

and

Wat

erVa

por(

W&

W)

Influ

ence

of

wat

er v

apor

eon

SLR

/LLR

(Mar

ini-M

urra

y):

ez

SLR wet

trp

⋅≈

=00

0141

.0)0

(,

δρIn

fluen

ce o

f w

ater

vap

or o

n G

PS/V

LBI/D

OR

IS (S

aast

amoi

nen)

:

Rat

io o

f Mic

row

ave/

SLR

:

ee

Tz

Micro wet

trp

⋅≈

⋅

+⋅

≈=

0096

.005.0

1225

0022

77.0

)0(

,δρ Wet

del

ay: G

PS/V

LBI/D

OR

IS u

p to

40

cm; S

LR u

p to

6 m

m

Trop

osph

ere

zeni

th d

elay

par

amet

ers ―

wea

keni

ng th

e so

lutio

ns ―

have

to b

e es

timat

ed fo

r mic

row

ave

tech

niqu

es, b

ut n

ot fo

r SLR

68)0

()0

(

,,≈

==zz

SLR wet

trpMicro wet

trp

δρδρ

ILR

S W

orks

hop

2003

, Oct

ober

28-3

1, 2

003,

Köt

ztin

g, G

erm

any

Clo

cks

and

Cor

rela

tions

(C&

C)

Estim

atio

n of

clo

ck p

aram

eter

s:

•SL

R: t

he o

nly

tech

niqu

e, w

here

in g

ener

al n

o cl

ock

corr

ectio

nsha

ve

to b

e es

timat

ed•

GPS

: rec

eive

r and

sat

ellit

e cl

ock

para

met

ers

for e

very

epo

ch•

VLB

I: re

ceiv

er c

lock

cor

rect

ions

abo

ut e

very

hou

r (be

twee

n st

atio

ns)

•D

OR

IS: c

lock

bia

ses

have

to b

e es

timat

ed to

o

Estim

atio

n of

clo

ck p

aram

eter

s de

grad

es th

e he

ight

qua

lity

Exce

ptio

ns fo

r SLR

:•

Estim

atio

n of

a ra

nge

bias

for a

n S

LR s

tatio

n: c

orre

spon

ds to

a

rece

iver

clo

ck c

orre

ctio

nin

GP

S/V

LBI/D

OR

IS

•Es

timat

ion

of a

tim

e bi

ases

for a

n S

LR s

tatio

n

Estim

atio

n of

rang

e bi

ases

sho

uld

be a

void

ed to

the

exte

nt p

ossi

ble

ILR

S W

orks

hop

2003

, Oct

ober

28-3

1, 2

003,

Köt

ztin

g, G

erm

any

Para

met

er Z

enith

-Dep

ende

nce

z

z

.

..

.

z

Sta

tion

Hei

ght

Zeni

th T

ropo

sphe

reD

elay

Clo

ckC

orre

ctio

n()

()

() 0

cos

hh

zz

δρδρ

⋅=

()

()

() 0

cos1

trp

trp

zz

δρδρ

⋅=

()

()

Rclk

clk

tc

zδ

δρδρ

⋅=

=0

ILR

S W

orks

hop

2003

, Oct

ober

28-3

1, 2

003,

Köt

ztin

g, G

erm

any

Cor

rela

tion:

Hei

ght,

Clo

cks,

Tro

posp

here

•In

fluen

ce o

f clo

ck a

nd

tropo

sphe

re e

stim

atio

n on

st

atio

n he

ight

(San

terr

e)

•Ex

trem

e co

rrel

atio

ns

betw

een

heig

ht, c

lock

, and

tro

posp

here

zen

ith d

elay

•N

o pr

oble

m fo

r SLR

: he

ight

s sh

ould

be

perfe

ct

Coo

rd. +

Clo

ckC

oord

. onl

yC

oord

.+Tr

opo.

z max

σ1 h

/σ0 h

Co

r(h

,trp

)70

13.7

8-0

.964

759.

23-0

.943

806.

13-0

.907

853.

94-0

.830

ILR

S W

orks

hop

2003

, Oct

ober

28-3

1, 2

003,

Köt

ztin

g, G

erm

any

Obs

erva

tion

Geo

met

ry

Nic

eob

serv

atio

nge

omet

ryfo

rgoo

d st

atio

ns(1

4 da

ys)

Wel

l-sui

ted

for

heig

htde

term

inat

ion

SLR

ver

y im

port

ant f

or

abso

lute

hei

ght

estim

atio

n Es

timat

ion

of

rang

e bi

ases

sh

ould

be

avoi

ded

to th

e ex

tent

po

ssib

le

ILR

S W

orks

hop

2003

, Oct

ober

28-3

1, 2

003,

Köt

ztin

g, G

erm

any

Ant

enna

san

d A

bsol

ute

Scal

e(A

&A

)C

hara

cter

istic

s of

GPS

rece

iver

and

sat

ellit

e an

tenn

as:

•N

ot a

ccur

atel

y kn

own,

cha

ngin

g w

ith e

leva

tion

and

azim

uth

•G

PS

resu

lts d

epen

dent

on

elev

atio

n cu

t-off

•La

rge

syst

emat

ic e

ffect

s du

e to

ant

enna

pha

se c

ente

rcor

rect

ions

(r

ecei

ver a

nd s

atel

lite

ante

nnas

)•

Man

y ch

ange

s of

GP

S re

ceiv

er/a

nten

na e

quip

men

t (ju

mps

in h

eigh

t)•

GP

S is

too

muc

h af

fect

ed b

y sy

stem

atic

effe

cts

to a

llow

acc

urat

eab

solu

te h

eigh

tand

abs

olut

e sc

ale

dete

rmin

atio

n in

the

glob

al

netw

ork

and

for I

TRF.

VLB

I tel

esco

pes:

•V

LBI t

eles

cope

s ar

e hu

ge a

nd h

eavy

stru

ctur

es•

VLB

I tel

esco

pe d

efor

mat

ion

may

bia

s re

sults

(ele

vatio

n de

pend

ence

?)

SLR

: no

such

ant

enna

pro

blem

s (d

efor

mat

ion

shou

ld b

e sm

all,

no

phas

e ce

nter

var

iatio

ns):

wel

l-sui

ted

to d

efin

e sc

ale

of IT

RF;

but

ca

libra

tion

has

to b

e ve

ry a

ccur

ate

and

relia

ble.

ILR

S W

orks

hop

2003

, Oct

ober

28-3

1, 2

003,

Köt

ztin

g, G

erm

any

Ant

enna

Phas

e C

ente

r Cor

rect

ions

Ant

enna

phas

ece

nter

varia

tions

:

•G

PS

rece

iver

ante

nna

•G

PS

sat

ellit

ean

tenn

a

ILR

S W

orks

hop

2003

, Oct

ober

28-3

1, 2

003,

Köt

ztin

g, G

erm

any

GPS

: Ele

vatio

n C

ut-O

ff Ef

fect

•C

hang

e of

sta

tion

coor

dina

tes

due

to a

ch

ange

in e

leva

tion

cut-o

ff an

gle

•M

ost u

p-to

-dat

e ab

solu

te p

hase

cen

ter

varia

tions

used

for

rece

iver

s (r

obot

m

easu

rem

ents

) and

sa

telli

tes

(glo

bal

estim

atio

n)

•A

nten

nas

are

a cr

itica

l er

ror s

ourc

e !

ILR

S W

orks

hop

2003

, Oct

ober

28-3

1, 2

003,

Köt

ztin

g, G

erm

any

GPS

: Abs

olut

e-R

elat

ive

Ant

enna

Patte

rns

•C

hang

e fro

m re

lativ

e (n

ow in

use

) to

abso

lute

ant

enna

in

form

atio

n (to

be

used

by

IGS

in

futu

re)

•A

bsol

ute

phas

e ce

nter

var

iatio

ns o

nly

deriv

able

with

fixe

d IT

RF

scal

e.

•Sy

stem

atic

cha

nge

in

scal

e to

ITR

F (s

ever

al m

m)

ILR

S W

orks

hop

2003

, Oct

ober

28-3

1, 2

003,

Köt

ztin

g, G

erm

any

Com

paris

onof

GPS

& V

LBI T

ropo

sphe

re

•C

ON

T’02

Cam

paig

n (1

4 da

ys)

•V

ery

nice

agr

eem

ent i

n te

mpo

ral v

aria

tions

, but

larg

e sy

stem

atic

bi

ases

betw

een

VLB

I and

GP

S, i

ndic

atin

g so

me

unm

odel

edef

fect

s

ILR

S W

orks

hop

2003

, Oct

ober

28-3

1, 2

003,

Köt

ztin

g, G

erm

any

Com

paris

onof

GPS

& V

LBI T

ropo

sphe

re

Diff

eren

ce b

etw

een

GPS

and

VLB

I

0510152025

ALGO

FAIR

HRAO

KOKB

NYA1

ONSA

WES2

WTZR

Zenith Trop. Delay [mm]

Theo

ryEs

timat

es

4.5

0.9

3.10

WTZ

R

11.7

0.5

1.75

WE

S2

5.1

4.1

13.7

1O

NS

A

1.7

0.9

3.07

NY

A1

14.2

2.8

9.24

KO

KB

7.8

0.5

1.54

HR

AO

6.8

3.9

13.0

8FA

IR

14.0

6.9

23.1

1A

LGO

∆ZT

DE

stim

.[m

m]

∆ZT

DTh

eory

[mm

]

∆H

eigh

t(lo

calt

ie)

[m]

Sta

tion

∆H

eigh

t= 1

0m →

∆ZD

≈3m

m

ILR

S W

orks

hop

2003

, Oct

ober

28-3

1, 2

003,

Köt

ztin

g, G

erm

any

Rot

atio

n an

d R

otat

ion

Rat

es (R

&R

)O

ne-to

-one

rela

tion

betw

een

chan

ges

in U

T1-U

TC, ∆

ε, ∆ψ

and

chan

ges

in th

eor

bita

l ele

men

tsΩ

, i, u

0 (ρ

=1.0

0273

79):

→U

T1-U

TC a

nd n

utat

ion

offs

ets

cann

otbe

estim

ated

toge

ther

with

orbi

tal e

lem

ents

→LO

D a

nd n

utat

ion

rate

sca

nbe

estim

ated

bysa

telli

tete

chni

ques

; qu

ality

of o

rbit

mod

elis

cruc

ial(

chan

ges

of e

lem

ents

with

time)

ILR

S W

orks

hop

2003

, Oct

ober

28-3

1, 2

003,

Köt

ztin

g, G

erm

any

UT1

-UTC

and

Nut

atio

nfr

omSL

R

ILR

S W

orks

hop

2003

, Oct

ober

28-3

1, 2

003,

Köt

ztin

g, G

erm

any

LOD

and

Nut

atio

nR

ates

from

SLR

ILR

S W

orks

hop

2003

, Oct

ober

28-3

1, 2

003,

Köt

ztin

g, G

erm

any

Nut

atio

nfr

omSL

R, G

PS, a

nd V

LBI

•C

ompa

rison

of n

utat

ion

durin

gth

eC

ON

T’02

Cam

paig

n(1

4 da

ys)

•S

LR re

sults

sim

ilart

o th

ose

of G

PS

(at l

east

in o

bliq

uity

)

ILR

S W

orks

hop

2003

, Oct

ober

28-3

1, 2

003,

Köt

ztin

g, G

erm

any

LOD

from

SLR

, GPS

, and

VLB

I •C

ON

T’02

C

ampa

ign

(1

4 da

ys)

•S

ubda

ilyLO

D

from

GP

S a

nd

VLB

I

•D

aily

val

ues

from

SLR

(L

ageo

s1

+ 2)

ILR

S W

orks

hop

2003

, Oct

ober

28-3

1, 2

003,

Köt

ztin

g, G

erm

any

X-an

d Y-

Pole

from

SLR

CO

NT’

02 C

ampa

ign

ILR

S W

orks

hop

2003

, Oct

ober

28-3

1, 2

003,

Köt

ztin

g, G

erm

any

Geo

met

ryan

d G

ravi

ty(G

&G

)

SLR

is o

ne o

f the

maj

or te

chni

ques

to e

stab

lish

a lin

k be

twee

n ge

omet

ry, E

arth

rota

tion,

and

gra

vity

(thr

ee p

illar

s of

geo

desy

):

•G

eoce

nter

: rel

atio

n be

twee

n or

igin

of I

TRF

and

low

ord

er h

arm

onic

s co

effic

ient

C01

, C11

, S11

of th

e E

arth

’s g

ravi

ty fi

eld

•P

rinci

ple

axes

of i

nerti

a te

nsor

: rel

atio

n be

twee

n E

arth

rota

tion,

or

ient

atio

n of

the

grav

ity fi

eld

(C21

, S21

, S22

), an

d IT

RF

orie

ntat

ion

•H

elp

to d

istin

guis

h be

twee

n “m

atte

r ter

ms”

and

“mot

ion

term

s”

(gra

vity

“fee

ls” o

nly

“mat

ter”

, Ear

th ro

tatio

n “m

atte

r” a

nd “m

otio

n”)

SLR

as

a lin

k be

twee

n 3

pilla

rs: v

ery

impo

rtant

for t

he IG

GO

S in

tegr

atio

n co

ncep

t and

for I

ER

S re

fere

nce

fram

e de

finiti

ons

Gra

vity

fiel

d va

riatio

ns d

ue to

exa

ctly

the

sam

e Ea

rth

proc

esse

s(e

.g.,

from

geo

phys

ical

flui

ds) a

s E

arth

rota

tion

and

defo

rmat

ion

(geo

met

ry)

ILR

S W

orks

hop

2003

, Oct

ober

28-3

1, 2

003,

Köt

ztin

g, G

erm

any

Thre

eLa

yers

of O

bjec

ts

ILR

S W

orks

hop

2003

, Oct

ober

28-3

1, 2

003,

Köt

ztin

g, G

erm

any

Orb

its a

nd „

Obs

erve

d-C

ompu

ted“

(O&

O)

Valid

atio

n of

GN

SS o

rbits

(GPS

, Glo

nass

, Gal

ileo,

…):

•S

LR m

easu

rem

ents

are

suc

cess

fully

use

d to

val

idat

e G

NS

S o

rbits

•Sy

stem

atic

bia

sof

abo

ut 4

-5 c

m(!)

bet

wee

n G

PS

orb

its fr

om

mic

row

ave

and

SLR

obs

erva

tions

―re

ason

stil

l unc

lear

•M

ay b

ecom

e im

porta

nt fo

r Gal

ileo

sate

llites

, too

Valid

atio

n of

Low

Ear

th O

rbite

r (LE

O) o

rbits

:•

Muc

h pr

ogre

ss in

pre

cise

orb

it de

term

inat

ion

(PO

D) o

f LEO

sth

anks

to v

alid

atio

n w

ith S

LR “o

bser

ved-

com

pute

d” (O

-C)

•Ev

alua

tion

of d

iffer

ent s

trat

egie

s(k

inem

atic

, red

uced

-dyn

amic

, …)

and

softw

are

pack

ages

and

para

met

eriz

atio

ns•

SLR

“O-C

” val

ues

allo

w d

etec

tion

of s

yste

mat

ic o

rbit

erro

rs

SLR

obs

erva

tions

are

ext

rem

ely

valu

able

for P

OD

stu

dies

; PO

D

beco

mes

eve

r mor

e cr

ucia

l for

new

sat

ellit

e m

issi

ons

ILR

S W

orks

hop

2003

, Oct

ober

28-3

1, 2

003,

Köt

ztin

g, G

erm

any

SLR

Val

idat

ion

of C

HA

MP

GPS

Orb

its

ILR

S W

orks

hop

2003

, Oct

ober

28-3

1, 2

003,

Köt

ztin

g, G

erm

any

CH

AM

P O

rbits

: Obs

erve

d-C

ompu

ted

•S

LR “O

-C” v

alue

s (o

r res

idua

ls) s

till

show

sig

nific

ant s

yste

mat

ic

tren

dsfo

r ind

ivid

ual p

asse

s

•Si

mila

r beh

avio

r of k

inem

atic

and

redu

ced-

dyna

mic

orbi

t res

idua

ls

•D

etai

led

anal

ysis

of t

he re

sidu

als

may

giv

e in

form

atio

n on

mod

el

defic

ienc

es, e

.g.:

–G

PS

pol

ariz

atio

n ef

fect

–R

elat

ivis

tic c

orre

ctio

ns–

Hig

her o

rder

iono

sphe

ricco

rrec

tions

–

Orb

it pa

ram

eter

izat

ion

…

ILR

S W

orks

hop

2003

, Oct

ober

28-3

1, 2

003,

Köt

ztin

g, G

erm

any

Futu

re C

ombi

natio

n: "

Wee

kly"

SIN

EX S

olut

ions

IVS

AC

1IV

S A

C 2

IVS

AC

n

Site

Coo

rd.,

EO

Ps,

Qua

sar

Coo

rd.

IGS

AC

1IG

S A

C 2

IGS

AC

n

Site

Coo

rdin

ates

, EO

Ps

ILR

S A

C 1

ILR

S A

C 2

ILR

S A

C n

Site

Coo

rdin

ates

, EO

Ps

IDS

AC

1ID

S A

C 2

IDS

AC

n

Site

Coo

rdin

taes

, EO

Ps

IVS

Com

bina

tion

Site

Coo

rd.,

EO

Ps,

Qua

sar C

oord

.

IGS

Com

bina

tion

Site

Coo

rdin

ates

, EO

Ps

ILR

S C

ombi

natio

n

Site

Coo

rdin

ates

, EO

Ps

IDS

Com

bina

tion

Site

Coo

rdin

ates

, EO

Ps

Com

bine

d"w

eekl

y"

Inte

r-te

chni

que

Solu

tions

Site

Coo

rdin

ates

, EO

Ps,

Qua

sar C

oord

inat

es

IER

S C

ombi

natio

n C

ente

rs

Loca

l Tie

Info

rmat

ion

Rem

ove

Bia

ses

Bet

wee

n Te

chni

ques

VLB

IG

PSSL

R/L

LRD

OR

IS

ILR

S W

orks

hop

2003

, Oct

ober

28-3

1, 2

003,

Köt

ztin

g, G

erm

any

Futu

re C

ombi

natio

n: M

ulti-

Year

Sol

utio

ns(F

ully

Con

sist

ent S

et o

f ITR

F/EO

Ps/IC

RF)

Wee

k 1

Wee

k 2

Wee

k n

Com

bine

dS

olut

ions

:S

ite C

oord

., E

OP

s,Q

uasa

r Coo

rdin

ates

Tim

e Se

ries

of S

ite C

oord

inat

es

ITR

F

Site

Coo

rdin

ates

+S

ite V

eloc

ities

EOP

Com

bine

d S

erie

sX

p, Y

p, U

T1,

∆ε,

∆ψ

ICR

F

Qua

sar C

oord

.+

Qua

sar M

otio

n

Tim

e Se

ries

of E

OPs

Tim

e Se

ries

of Q

uasa

r Coo

rdin

ates

Pre

-elim

inat

ion

of E

OP

sR

esub

stitu

tion

(Hel

mer

tBlo

ckin

g)

Han

dlin

g of

Site

Cha

nges

, N

on-li

near

Mot

ion

Ann

ual S

igna

ls

Sam

e flo

wch

art a

lso

valid

for

indi

vidu

al te

chni

ques

ILR

S W

orks

hop

2003

, Oct

ober

28-3

1, 2

003,

Köt

ztin

g, G

erm

any

Mea

surin

gan

d M

odel

ing

the

Eart

h Sy

stem

Mea

surin

g In

form

atio

n ab

out E

arth

Sys

tem

Influ

ence

/ M

odel

ling

Obs

erva

tion

Mod

ellin

g

Spac

e G

eode

tic

Tech

niqu

es

VLB

I

SLR

LLR

GP

S

DO

RIS

Alti

met

ry

InS

AR

Rin

glas

er

Geo

met

ry

Sta

tion

Pos

ition

/Mot

ion,

Sea

Leve

l Cha

nge,

Def

orm

atio

n

Eart

h R

otat

ion

Pre

cess

ion/

Nut

atio

n,P

olar

Mot

ion,

U

T1, L

OD

Gra

vity

Geo

cent

erG

ravi

ty fi

eld,

Te

mpo

ral v

aria

tions

Eart

h Sy

stem

(incl

. GG

F)

Sun

/Moo

n

(Pla

nets

)

Atm

osph

ere

Oce

an

Hyd

rosp

here

Cry

osph

ere

Cor

e

Man

tle

Cru

st

C O M B I N A T I O N

I N T E R A C T I O N S

ILR

S W

orks

hop

2003

, Oct

ober

28-3

1, 2

003,

Köt

ztin

g, G

erm

any

Con

clus

ions

•S

LR h

as fe

w o

bser

vatio

ns, b

ut a

lso

few

par

amet

ers

to e

stim

ate

•S

LR is

the

only

opt

ical

tech

niqu

e (u

niqu

e to

ass

ess

atm

osph

ere

bias

es)

•N

o tro

posp

here

est

imat

ion

nece

ssar

y fo

r SLR

(cor

rela

tions

, bia

ses)

•N

o cl

ock

corr

ectio

n es

timat

ion

nece

ssar

y fo

r SLR

(cor

rela

tions

, bi

ases

) →

good

hei

ghts

•N

o bi

g an

tenn

a pr

oble

ms

→ab

solu

te s

cale

, hei

ghts

•Im

porta

nt li

nk b

etw

een

grav

ity, E

arth

rota

tion,

and

geo

met

ry•

SLR

O-C

cru

cial

for p

rogr

ess

in P

OD

SLR

is a

uni

que

part

ner i

n th

e go

al o

f a ri

goro

us c

ombi

natio

n of

the

spac

e ge

odet

ic te

chni

ques

(IER

S an

d IG

GO

S)Th

e in

divi

dual

tech

niqu

es s

houl

d fe

el a

s a

part

of a

larg

er w

hole

w

ith a

com

mon

goa

l rat

her t

han

wor

king

in c

ompe

titio

nIn

terli

nked

, the

tech

niqu

es a

re m

uch

stro

nger

and

it is

mor

e di

fficu

lt to

isol

ate

and

cut i

ndiv

idua

l tec

hniq

ues