Development Process of EPN Analysis - euref.eu Process of EPN Analysis Heinz Habrich EPN Analysis Coordinator Federal Agency for Cartography and Geodesy,Frankfurt, Germany EUREF Symposium,

Development Process of EPN Analysis

Development Process of EPN Analysis

Heinz Habrich

EPN Analysis Coordinator

Federal Agency for Cartography and Geodesy,Frankfurt, Germany

EUREF Symposium, 14 - 17 June 2006, Riga, Latvia 2

StatementStatement

� EPN Analysis is a continuous effortcontinuous effort...

...of Local Analysis Centres (LACs) in European

countries

...to realize an European Reference Frame in the most accurate manner

...and thus requires to question the applied methods to question the applied methods

and strategies all the timeand strategies all the time.


OutlineOutline

� Status of Local Analysis Centres

� Status of sub-network combination

� Local Analysis Centre Workshop 2006 in Padua, Italy

� Planned changes in the EPN analysis

� ITRF 2005 Densification

� TIGA co-operation


Status of Local Analysis Centres- Software Week 1369 (April 2006) -Status of Local Analysis Centres- Software Week 1369 (April 2006) -

Bernese 4.0

6%Bernese 4.2

25%

Bernese 5.0

51%

Bernese 5.1

6%

MicroCosm 2003.0

6%

GIPSY v2.5/cov2snx

6%

Bernese 4.0

Bernese 4.2

Bernese 5.0

Bernese 5.1

MicroCosm 2003.0

GIPSY v2.5/cov2snx

General Intention:

Less „strict analysis rules“, but more responsibility of LACs.

ASI MicroCosm 2003.0

BEK Bernese 4.2

BKG Bernese 5.0

COE Bernese 5.1

DEO GIPSY v2.5/cov2snx

GOP Bernese 5.0

IGE Bernese 5.0

IGN Bernese 4.2

LPT Bernese 5.0

NKG Bernese 5.0

OLG Bernese 4.2

ROB Bernese 5.0

SGO Bernese 4.2

SUT Bernese 4.0

UPA Bernese 5.0

WUT Bernese 5.0

Radome codes and FES2004 ocean loading model


Status of sub-network combinationStatus of sub-network combination

0

1

2

3

4

5

6

1290 1300 1310 1320 1330 1340 1350 1360 1370 1380

Weeks

[mm

]

North

East

Height

Week 1372

0

1

2

3

4

5

6

BEK BKG COE GOP IGE IGN LPT NKG OLG ROB SGO SUT UPA WUT

[mm

]

North

East

Height

Day to Day RepeatabilityPrecision between LACs

Indication of Precision


NoteNote

� The formal error of the least squares adjustment is not suitable as indicator of the precision in GPS analysis,

because correlations between observations are not

correctly modelled.

� We may use residuals between sub-network solutions

or day-to-day repeatability of the stations as alternativeindicator for the achieved precision.


5th LAC Workshop5th LAC Workshop

� Date and Venue: University of Padua, Italy, March 15 – 16, 2006

� 37 registered participants from 15 European Nations

� 15 LACs represented, 1 LAC not represented after short-term cancellation

� 5 Working Sessions:

– Session 1: Reports from the EPN Coordination Group

– Session 2: Local Analysis Centres reports

– Session 3: Experiences with new processing strategies

– Session 4: Site, receiver and antenna issues

– Session 5: Wrap-up and closing session


„Inspiration“ from Galileo‘s Chair„Inspiration“ from Galileo‘s Chair


LAC Workshop Conclusions (1/7)- Absolute Phase Centre Variations -LAC Workshop Conclusions (1/7)- Absolute Phase Centre Variations -

� Absolute phase centre variations (APCV) will be introduced simultaneously with the IGS

� At the same time switch to ITRF2005

� APCVs will be taken from IGS ANTEX file. For Bernese Software users:

– Use converter programme to generate Bernese files from ANTEX, or

– Use Bernese satellite/receiver files as provided by CODE

� EPN will preferable use APCV from robot calibrations of GEO++ company in Hannover, Germany for stations that are missing in IGS ANTEX file.

� Use „NONE“ as ball-back for antenna without radome codes

� Perform a „preparation step“ (relative PCV, but new format and radome codes), detailed instructions will be given by CODE


RemarkRemark

� New results of APCV have been presented at the IGS workshop in May 2006:

– Frequency dependent receiver PCV for GLONASS signals

– Update of IGS ANTEX file expected!

Presented by Geo++

at IGS 2006 Workshop

�GPS – GLONASS

GLONASS-GLONASS�


LAC Workshop Conclusions (2/7)- Tropospheric Gradients -LAC Workshop Conclusions (2/7)- Tropospheric Gradients -

� Estimation of tropospheric gradients simultaneously with the introduction of APCV

� Pre-elimination of gradients before submission of TROP SINEX files (not supported by format)


LAC Workshop Conclusions (3/7)- GLONASS -LAC Workshop Conclusions (3/7)- GLONASS -

� LACs are authorised to add GLONASS observations to their GPS analysis, provided the results are not

degraded

� LACs recommend

– to replace obsolete GPS equipment with

GPS/GLONASS/GALILEO equipment and

– propose to assess the recommendation with a

EUREF symposium resolution


LAC Workshop Conclusions (4/7)- Re-Processing -LAC Workshop Conclusions (4/7)- Re-Processing -

� General agreement between LACs on EPN re-processing of all observations since the beginning of the

EPN

� Action is postponed until re-processed final IGS orbits

are available


LAC Workshop Conclusions (5/7)- Real-Time Strategies -LAC Workshop Conclusions (5/7)- Real-Time Strategies -

� Discussion about strategies for real-time (RT) data analysis postponed until RT software becomes available


LAC Workshop Conclusions (6/7)- Near Real-Time Processing -LAC Workshop Conclusions (6/7)- Near Real-Time Processing -

� Objective:

– Near real-time (NRT) processing is useful for monitoring of station coordinates.

� Concept:

– LACs already doing NRT processing submit hourly SINEX files to a „central place“

– Coordinate check and alert generation at „central place“

� Actors and details to be determined

� LACs are asked to cooperate with NMAs and to contribute with dense national networks to meteorological applications (TOUGH/E-GVAP)


LAC Workshop Conclusions (7/7)- Divers -LAC Workshop Conclusions (7/7)- Divers -

� Switch from GOT002 to FES2004 ocean loading model simultaneously with APCV and ITRF2005

� Proposal for a „rapid EPN combination product“.

– Providing coordinates with significant reduced delay

– Strict time table without waiting for missing LAC contributions

– Details to be discussed in the near future


Planned Changes in the EPN AnalysisPlanned Changes in the EPN Analysis

� APCV, ITRF2005 and tropospheric gradients simultaneously

� IGS ANTEX file as reference for APCV, but

– Completion for EPN sites required,

– Book keeping of radome types, and if necessary individual series number (with time stamps ?)

– Geo++ data base access

� Legal restrictions

� Disadvantages caused by updates

– Update of GLONASS numbers expected

– Open questions, e.g., maintenance of official EPN phase file?


Relative vs. Absolute PCV- BKG Sub-Network Week 1374 -Relative vs. Absolute PCV- BKG Sub-Network Week 1374 -

� Analysis by Peter Franke

Absolute vs. Relative PCV Site Replacemant

-15

-10

-5

0

5

10

15

20

25

30

35

MO

XA

TR

AB

BU

TE

MA

LL

AL

ME

TU

BI

GO

TH

HU

EG

IST

AT

ITZ

CL

AU

NIC

ON

EW

LB

UC

UE

VP

AZ

WE

2E

NT

ZL

AM

PW

TZ

AA

UT

1A

NK

RP

TB

BG

RE

IY

EB

ES

TA

SK

IRU

GL

SV

TR

DS

HE

LG

VF

CH

AU

RI

OS

NA

MS

EL

CO

ST

OB

E2

RE

YK

OR

IDD

AU

NM

AT

ES

OF

IH

OF

NM

OR

EF

BG

KA

RL

HF

LK

LE

IPD

ILL

NP

LD

DR

ES

WT

ZJ

ER

LA

HE

RS

VIL

0K

LO

PH

ER

TM

UE

JO

NS

AP

OT

SM

ET

SE

US

KP

FA

NG

RA

ZZ

IMM

HO

BU

FF

MJ

WR

OT

RF

BP

OU

SB

AD

HB

OR

KK

OS

GS

BG

ZS

NE

CW

TZ

RB

OR

JB

RU

SH

EL

2D

IEP

LD

B2

GO

RL

HO

L2

HO

E2

SM

IDW

AR

BU

DP

SA

SS

[mm

] North

East

Height


NoteNote

� The BKG sub-network was analysed with relative and absolute PCV numbers. The so-called „preparation

step“ for relative PCV has been carried out before.

� Nearly 50 % of the stations experience height changes

of larger than 5 mm

� It should be considered that minimum constraints have been applied to selected reference sites. This will

restrict changes for the reference site coordinates.


Height Changes for Antenna Groups

-15

-10

-5

0

5

10

15

20

25

30

35

0 10 20 30 40 50 60 70 80 90

[mm

]

TRM22020.00+GP TCWD

TRM23903.00 TCWD

TRM33429.20+GP NONE

TRM33429.20+GP TCWD

TRM29659.00 NONE

TRM29659.00 TCWD

TRM29659.00 SCIS

TRM29659.00 UNAV

TRM29659.00 SNOW

TRM29659.00 GRAZ

TRM41249.00 NONE

TRM41249.00 TZGD

AOAD/M_T NONE

AOAD/M_B NONE

AOAD/M_B DUTD

AOAD/M_B OSOD

JPSREGANT_SD_E NONE

TPSCR3_GGD CONE

ASH700936C_M SNOW

ASH700936D_M SNOW

ASH700936E NONE

ASH700936E SNOW

ASH701941.1 SNOW

ASH701941.B UNAV

ASH701945B_M NONE

ASH701945C_M GRAZ

ASH701945E_M SCIS

ASH701946.2 NONE

LEISR399_INT NONE

LEIAT504 LEIS

LEIAT504 GRAZ


NoteNote

� The height changes evoked by the APCV have been ordered by antenna/dome types.

� For some types we observe common height changes, whereas other types shows several changes.

� The minimum constrained condition for the reference

stations may affect this result.


Contribution of EPN to ITRF2005Contribution of EPN to ITRF2005

� December 16, 2004: Call for „weekly“ SINEX files for ITRF2004

� Combination of time series of station positions and EOPs from all techniques

� EPN contributes to GPS technique

– with weekly SINEX files

– IGS (NRCan) combines weekly solutions

– only IGS stations of EPN will be included

� EUREF was asked to check the discontinuity table used by NRCan

– Done by Ambrus Kenyeres on the part of Time Series SP

– Check will performed by Heinz Habrich (EPN AC) too


Densification of ITRF2005Densification of ITRF2005

� Initiative within IAG sub-commission 1.3 „Regional Reference Frames“ in responsibility of Zuheir Altamimi

� Time-integrated solutions (positions and velocities) of 6 regional sub-commissions have been inquired

� EPN contributes to regional European network

– computation of corresponding a multi-year solution


New EPN Multi-year Solution 2005- Strategy -New EPN Multi-year Solution 2005- Strategy -

� Conversion of all EPN weekly SINEX files into normal equations (NEQs) without option „reconstruction of original NEQ“ (coordinate=observation).

� Inconsistency file from time series SP as a-priori information, but additional editing because of singularities in ADDNEQ2.

� Minimum constraint conditions (MCC) for datum definition (2 stepapproach to store SINEX file).

� Setup of stations velocities.

� Observations of weeks 860 (30 Jun 1996) – 1355 (31 Dec 2005)


New EPN Multi-year Solution- Processing Statistics-New EPN Multi-year Solution- Processing Statistics-

Quasi FixedMCC

RMS = 0.1 mmCoordinate comparison

3 h 30 minProcessing Time for

ADDNEQ2

266266Number of stations

(+ solution numbers)

3.42 mm3.42 mmA-posteriori RMS

1596/1517581596/151758Number of

parameters/observations

0.1 mm Constraint for all sites

Minimum Constraint for 21 sites

Datum Definition


Excluded EPN Solutions (14 weeks)Excluded EPN Solutions (14 weeks)

?EUR13347.SNX

No „solution epoch“ in SINEX

EUR13117.SNX, EUR13127.SNX,



EUR13187.SNX

?EUR8977.SNX

Internal station number GRASEUR8737.SNX

?EUR8707.SNX, EUR8717.SNX,

EUR8727.SNX

Internal station number MATEEUR08617.SNX


Helmert Transformation- Weekly Networks vs. Combined -Helmert Transformation- Weekly Networks vs. Combined -

0

0,001

0,002

0,003

0,004

0,005

0,006

0,007

0,008

860 910 960 1010 1060 1110 1160 1210 1260 1310

Weeks

RM

S [

m]

RMS of Helmert TransformationSmoothed


NoteNote

� The variation of the RMS for the Helmert transformation may lead to the assumption of a changing analysis

accuracy. But it will be shown later that it depends on

the reference station selection.


-0,005

-0,004

-0,003

-0,002

-0,001

0

0,001

0,002

0,003

0,004

0,005

0,006

860 910 960 1010 1060 1110 1160 1210 1260 1310

Weeks

Scale

[p

pm

]

Scale

Smoothed

-0,05

-0,04

-0,03

-0,02

-0,01

0

0,01

0,02

0,03

860 910 960 1010 1060 1110 1160 1210 1260 1310

Weeks

Y-S

hif

t [m

]

X-Shift

Smoothed

-0,06

-0,05

-0,04

-0,03

-0,02

-0,01

0

0,01

0,02

0,03

0,04

0,05

860 910 960 1010 1060 1110 1160 1210 1260 1310

Weeks

Y-S

hif

t [m

]

Y-Shift

Smoothed

-0,04

-0,03

-0,02

-0,01

0

0,01

0,02

0,03

860 910 960 1010 1060 1110 1160 1210 1260 1310

Weeks

Z-S

hif

t [m

]

Z-Shift

Smoothed


-0,0015

-0,001

-0,0005

0

0,0005

0,001

0,0015

860 910 960 1010 1060 1110 1160 1210 1260 1310

Weeks

X-R

ota

tio

n [

"]X-Rotation

Smoothed

-0,0012

-0,001

-0,0008

-0,0006

-0,0004

-0,0002

0

0,0002

0,0004

0,0006

0,0008

0,001

860 910 960 1010 1060 1110 1160 1210 1260 1310

Weeks

Y-R

ota

tio

n [

"]

Y-Rotation

Smoothed

-0,0015

-0,001

-0,0005

0

0,0005

0,001

860 910 960 1010 1060 1110 1160 1210 1260 1310

Weeks

Z-R

ota

tio

n [

"]

Z-Rotation

Smoothed


NoteNote

� The following two plots show the periods for which each reference station contributes to the datum definition of

the multiyear solution.

� New „solution numbers“ of a station become mandatory

after a coordinate change with the consequence that

ITRF2000 coordinates are no longer valid.

� The setup of new solution numbers for reference

stations leads to a loss of reference sites over the years.

� The number of reference stations for each week is

highly correlated to the RMS of weekly Helmert parameters as mentioned before.


860 910 960 1010 1060 1110 1160 1210 1260 1310 1360

GPS Weeks

BOR1

BRUS

GLSV

GRAS

GRAZ

HOFN

JOZE

KOSG

LAMA

MATE

NICO

NYA1

NYAL

ONSA

POTS

REYK

VILL

WSRT

WTZR

ZIMM

ZIMM1

Sit

es

Reference Sites Contribution


Number of Reference Sites in Weekly Networks

0

2

4

6

8

10

12

14

16

18

20

860 910 960 1010 1060 1110 1160 1210 1260 1310

GPS Weeks

No

. o

f S

ite

s


AC

OR

13434M

001

BO

GI

12207M

003

-30

-20

-10

0

10

20

30

40

50

60

70

mm

Stations

East

AC

OR

13

43

4M

00

1

BO

GI

12

20

7M

00

3

-140

-120

-100

-80

-60

-40

-20

0

20

40

60

mm

Stations

Height

AC

OR

13

43

4M

00

1

BO

GI

12

20

7M

00

3

-40

-20

0

20

40

60

80

100

120

mm

Stations

North

Estimated Station VelocityEstimated Station Velocity


NoteNote

� Significant velocities for stations...

– ...not located on stable part of European plate

– ...new stations having just a little solutions

– ...other reasons??


Velocity Correction to a-priori Velocity Correction to a-priori

AJ

AC

10

07

7M

00

5

-20

-10

0

10

20

30

40

50

mm

Stations

East

AJ

AC

10

07

7M

00

5

-40

-20

0

20

40

60

80

100

mm

Stations

North

AJA

C 1

0077M

005

-140

-120

-100

-80

-60

-40

-20

0

20

40

60

mm

Stations

Height


NoteNote

� Shown are the differences between estimated station velocities and the a-priori quantities. A-priori velocities

are ITRF2000 solutions and alternatively results from

the Nuvel model.

� Velocity corrections for height components are mostly

identical to the absolute velocity estimation, because Nuvel 1A-NNR model applies only horizontal motions.


ITRF2005 Densification- Next Steps -ITRF2005 Densification- Next Steps -

� Comparison of jumps and outliers with IGS (for IGS stations of EPN) and Time Series SP (for remaining

EPN sites)

� Investigation of residuals for coordinates and velocities

� Check for Remaining outliers

� Investigation of the variation of weekly Helmert transformation parameters

� Apply additional reference coordinates/velocities from ITRF2005 as soon as available


TIGA CooperationTIGA Cooperation

� GFZ started recently working on a weekly combined solution of AUT, DGF, ETG, GFT, ULR and CTA contributions.

� Problems concerning correct station names and DOMES numbers have been identified.

� Combination for the period of 2002 has been performed for test purposes.

– Slightly improvement in height component compared to single AC solution,

– but large variation in scale parameter for regional solutions (AUT, DGF and ETG).

� Magnitude of scale variation for ETG complies with quantity of most recent EPN multi-year solution.



NoteNote

Graphics of previous slight

� Upper left:

– EPN sub-network that was submitted to TIGA for week 1368 (April 2006).

� Bottom left:

– Scale parameter between individual TIGA AC and combined solution for year 2002.

� Upper right:

– Scale parameter between weekly and multi-year EPN solution

� Bottom right:

– Zoomed scale parameter for year 2002


� For any suggestions and questions related to EPN analysis please contact

[email protected]

Thank you

Documents

Development Process of EPN Analysis - euref.eu Process of EPN Analysis Heinz Habrich EPN Analysis Coordinator Federal Agency for Cartography and Geodesy,Frankfurt, Germany EUREF Symposium,