Draft (V1.1)
Minutes of the
3rd ESEAS-RI WP2 Meeting
Place:
Puertos del Estado,
Madrid,
Spain
Date:
12-13 February 2004
| 
|
Minutes written by
Hans-Peter Plag
(Version of 20 February 2004).
Participants:
Hans-Peter Plag (HPP),
NMA,
(Coordinator, Task leader 2.4)
Per Knudsen (PK),
KMS,
(WP3 leader)
Marzenna Sztobryn (MSZ),
IMGW
Dov Rosen (DR),
IOLR,
(WP4 leader)
Belen Martin Miguez (BMM),
PE
Begona Perez Gomez (BPG),
PE,
(Task leader 1.4)
Richard Bingley (RB),
UNOTT,
(WP2 leader, Task leader 1.1 + 2.8)
Norman Teferle (NT),
UNOTT,
(Task leader 2.5)
Halfdan Pascal Kierulf (HPK),
NMA,
(Task leader 2.1 + 2.3)
Bojan Cernac (BC),
EARS
Coskun Demir (CD),
GCM,
(Task leader 2.7)
Cristina Garcia (CG),
ROA
Damia Gomis (DG),
UIB
Jorge Garate (JG),
ROA
Jose Martin Davila (JMD),
ROA
Enrique Alvarez Fanjul (EAF),
PE
Ryszard Zdunek (RZ),
SRC,
(Task leader 4.4)
Tilo Schoene (TIS),
GFZ Potsdam,
(Chair of the IGS TIGA WG)
Nenad Leder (NL),
HHI
Angela Aragon Angel (AAA),
UPC
Raul Orus Perez (ROP),
UPC
Leszek J. Jaworski (LJJ),
SRC
Juan Jose Martinez-Benjamin (JJMB),
UPC
Raul Orus Perez (ROP),
UPC
Angela Aragon Angel (AAA),
UPC
Agenda:
1 Task 2.6: Status and plans for absolute gravity measurements,
with a review of the requirements for an absolute gravity station
(if additional measurements to those described in the DoW are planned).
2 Minutes of the last WP2 meeting
3 Review of action items from the minutes of the last WP2
meeting (WP2/WG2-2-1 to WP2/WG2-2-15)
and action items relevant to WP4 from the minutes of the second
Project Team meeting (PT-2-9 and PT-2-18).
4 Task 2.3 (and Task 2.1): Status of CGPS Data Server, links to the
overall server, site documentation, status of test computations,
further progress towards operational processing and processing of
past data
5 Task 2.5 (and Task 2.2): What is still missing, what do we want from
Task 2.3, what additional parameters do we need (an update on
Task 2.4 will be included here), how to organise the work and the
exchange of results
6 Task 2.6: Status of database of absolute gravity measurements
7 Task 2.7: Structure of information to be collected, status of
what is available, further progress
8 Summary of Action Items
9 Date and place for the next meeting
1 Task 2.6: Status and plans for absolute gravity measurements,
with a review of the requirements for an absolute gravity station
(if additional measurements to those described in the DoW are planned).
Ryszard Zdunek
reported that for the site in Poland, Wladislawowo,
AG measurements are planned for May 2004 and also May 2005. The
site is about 1 km from the tide gauge.
Hans-Peter Plag
pointed out that for potential new AG sites,
it is necessary to set up requirements. This can be solved as part of the ESEAS TEC.
Action Item
WP2-3-1:
Richard Bingley
to initiate that requirements for AG sites are explicitly
written down. This task should be carried out in the frame of the
ESEAS TEC.
Responsible:
Richard Bingley,
Deadline:
31 August 2004.
Rational:
Clear requirements for AG sites should be made available on the ESEAS
web page to aid ESEAS members in case they want to upgrade a ESEAS Observing
Site for AG measurements.
2 Minutes of the last WP2 meeting
The minutes of the WP2-2 meeting were accepted with minor corrections.
3 Review of action items from the minutes of the last WP2
meeting (WP2/WG2-2-1 to WP2/WG2-2-15)
and action items relevant to WP4 from the minutes of the second
Project Team meeting (PT-2-9 and PT-2-18).
Richard Bingley
reviewed the AIs of the second WP2 meeting
(see
pdf
).
The relevant AIs from PT-2 are:
Action Item
PT-2-9:
Halfdan Pascal Kierulf
to split up the Version 1.0 strategy document of D2.1, into strategy and implementation.
Responsible:
Halfdan Pascal Kierulf,
Deadline:
30 Nov 2003.
Rational:
The strategy is expected not to change much in time while
implementation will evolve over time. Therefore, the two
parts should be separate documents.
Status of Action Item
PT-2-9:
Done.
Reported on 14/01/2004 by
ESEAS Central Bureau.
Action Item
PT-2-10:
Juan Jose Martinez-Benjamin
, UPC to add the results for their processing using GIPSY/OASIS II with PPP and JPL products to the ESEAS CGPS data a
Responsible:
Juan Jose Martinez-Benjamin,
Deadline:
15 Dec 2003.
Status of Action Item
PT-2-10:
Delayed.
Reported on 22/01/2004 by
Hans-Peter Plag.
Action Item
PT-2-11:
Halfdan Pascal Kierulf
to make the SINEX files and solution time series files from
all CGPS ACs available in the ESEAS CGPS DS.
Responsible:
Halfdan Pascal Kierulf,
Deadline:
16 Nov 2003.
Rational:
Making the SINEX files available will allow all Task group members
to compare the results and to find reasons for the differences in the coordinates.
Status of Action Item
PT-2-11:
Done.
Reported on 20/01/2004 by
ESEAS Central Bureau.
Action Item
PT-2-12:
All members of the Task 2.3 team to look at their own processing
of the extended sample data set and investigate how their results may
be improved, considering the results from the other members of the
task T2.3 team.
Responsible:
Halfdan Pascal Kierulf,
Deadline:
31 Dec 2003.
Rational:
The differences in the solutions are too large to be accepted. One step
is that every Analysis Centre tries to improve their own analysis procedure
individually.
Status of Action Item
PT-2-12:
Unknown.
Reported on 22/01/2004 by
Hans-Peter Plag.
Action Item
PT-2-13:
GCM and SRC to investigate any issues relating to their strategy for reference frame definition.
Responsible:
Halfdan Pascal Kierulf,
Deadline:
30 Nov 2003.
Action Item
PT-2-14:
NMA and ROA to re-process the extended sample data set using
GIPSY/OASIS II with PPP and IGS products and add these results to the
ESEAS CGPS data archive
Responsible:
Halfdan Pascal Kierulf,
Deadline:
30 Nov 2003.
Rational:
The results produced by UNOTT using Bernese with IGS products in precise
point positioning approach are considerable worse than all other solutions.
It is not clear whether this is due to the IGS products or Bernese ppp or
the combination of the two. Using GIPSY PPP with IGS, which seems to result
in degraded time series, will help to clarify the situation.
Status of Action Item
PT-2-14:
Unknown.
Reported on 22/01/2004 by
Hans-Peter Plag.
Action Item
PT-2-15:
UNOTT to make a conclusion regarding Bernese 4.2 with PPP and IGS products;
Responsible:
Richard Bingley,
Deadline:
15 Dec 2003.
Status of Action Item
PT-2-15:
Unknown.
Reported on 22/01/2004 by
Hans-Peter Plag.
Action Item
PT-2-16:
Hans-Peter Plag
to provide input for the strategy definition document for Task 2.2.
Responsible:
Hans-Peter Plag,
Deadline:
15 Dec 2003.
Status of Action Item
PT-2-16:
Unknown.
Reported on 22/01/2004 by
Hans-Peter Plag.
Action Item
PT-2-17:
Coskun Demir
and
Hans-Peter Plag
to define the master file for the levelling information.
Responsible:
Coskun Demir,
Deadline:
15 Dec 2003.
Status of Action Item
PT-2-17:
Delayed. Most of it is done. Will be finalised during the WP1 meeting..
Reported on 22/01/2004 by
Hans-Peter Plag.
Action Item
PT-2-18:
Coskun Demir
to contact others projects such as the EULVN project to find out which an how levelling information is compiled.
Responsible:
Coskun Demir,
Deadline:
15 Dec 2003.
Status of Action Item
PT-2-18:
Unknown.
Reported on 22/01/2004 by
Hans-Peter Plag.
The status was reviewed and described in
pdf
.
4 Task 2.3 (and Task 2.1): Status of CGPS Data Server, links to the
overall server, site documentation, status of test computations,
further progress towards operational processing and processing of
past data
Halfdan Pascal Kierulf
discussed the status of Task 2.1 and Task 2.3
(see
pdf
).
Part 1 of Task 2.1, i.e. the definition of the analysis strategy
is finished in the initial version.
Showing a comparison of daily coordinate values
of the different solution for the test
sites reveals that the
differences are of the order of several cm in all components.
There was considerable discussion concerning the realisation
of the reference frame, and it was pointed out that all
solutions can be considered as approximations to ITRF and
thus the differences seen indicate the accuracy achieveable
in the determination of coordinates in ITRF.
Time series for the test sites show differences in the rate
between GIPSY and GAMIT on the one side and Bernese on the
other site. The differences in RMS should be investigated
in more detail.
Norman Teferle
pointed out that it is worthwhile to continue with
Bernese ppp since IGS may go over to producing products
with 5 minutes sample rate and Bernese 5.0 is in the pipeline.
There is campaign data for a station DUGK on the ESEAS DS, but
it is not clear who provided the data. IBIZ and ANTA have good
quality.
For WLAD, the data shows non-linear behavour in the horizontal
component, which most likely is a seasonal cycle.
This may indicate an instability of the pier, where
the tide gauge and the GPS receiver are located.
Tilo Schoene
presented the work done by TIGA, the IGS Pilot project
(see
pdf
).
Tilo Schoene
justified the need to do a reprocessing in order to
get high quality orbits and clocks.
Richard Bingley
asked how
fra we can go back in time and use the available IGS products.
Tilo Schoene
assumes that from 2000, the products are reasonable.
Tilo Schoene
clarified that the reprocessed orbits and clocks will
not be made available for other users.
Norman Teferle
presented the results for UNOTT in more detail. UNOTT
uses Bernese 4.2 in ppp mode. In a first analysis, the
results were considerably worse than those of the other ACs.
Norman Teferle
showed that after a recommputation of the Bernese ppp
results, weighted rms has improved considerably
(see
pdf
or
ppt
).
The question to be answered soon is what global products
should be used. This has to be ansered by the ACs.
Coskun Demir
presented the work of GCM with respect to analysis
of GPS data (see
pdf
or
ppt
). GCM
uses GAMIT. The reference frame is fixed by a large number (38) IGS
stations, with main weight on European stations.
Raul Orus Perez
presented the analysis work of UPC
(see
pdf
).
UPC uses GIPSY. The results are comparable to the other GIPSY
groups.
There was considerable discussion concerning the understanding
of the JPL approach compared to regional network solutions.
Leszek J. Jaworski
presented the analysis work at SRC
(see
pdf
or
ppt
).
SRC uses Bernese with a regional network approach.
SRC investigated the dependency of daily coordinates on
different analysis parameters such as cut-off elevation.
For these tests, SRC constrains Wettzell to 1 mm and this may cause problems
if Wettzell has problems.
There was considerable discussion on whether IGS products can be
used for processing also at earlier times. The quality of these products
has increased over time and it is possible that e.g. in 2000 their quality
is not sufficient. In order to investigate this, the following
AI was agreed:
Action Item
WP2-3-2:
Halfdan Pascal Kierulf
to organise a new analysis test comparison with CGPS data for
Jan 2000 to present from approx. five
stations.
Responsible:
Halfdan Pascal Kierulf,
Deadline:
15 April 2004.
Rational:
This experiment is done in order to check whether older
IGS products are of sufficient quality to create
ESEAS time series. At least GIPSY PPP and Bernese network
solution should be compared, but preferably
all ACs should participate. It could also be worthwhile
to process all data for approx. five stations from
Jan 2000 to present, since this would give a chance to
determine and compare long-term rates.
It was also pointed out that for this test, stations should be selected
which are also processed by TIGA. Therefore, the following was agreed:
Action Item
WP2-3-3:
Richard Bingley
and
Halfdan Pascal Kierulf
together with
TS,
to select five stations
for the test in AI WP2-3-2, which are also processed by TIGA.
Responsible:
Richard Bingley,
Deadline:
15 March 2004.
With respect to documentation,
Hans-Peter Plag
presented briefly the ideas
behind the ESEAS Data Server, the Data Portal and introduced the
master files (see
pdf
). As a result,
the following AI was decided:
Action Item
WP2-3-4:
Hans-Peter Plag
to send out the Master files for GPS site documentation
to the GPS analysis groups for comments.
Responsible:
Hans-Peter Plag,
Deadline:
28 February 2004.
5 Task 2.5 (and Task 2.2): What is still missing, what do we want from
Task 2.3, what additional parameters do we need (an update on
Task 2.4 will be included here), how to organise the work and the
exchange of results
Halfdan Pascal Kierulf
introduced the draft ESEAS time series format
(see end of
pdf
), which
combines meta information with the data itself. The following
AI was decided.
Action Item
WP2-3-5:
Halfdan Pascal Kierulf
to send out the ESEAS Time series files for
comments.
Responsible:
Halfdan Pascal Kierulf,
Deadline:
28 February 2004.
6 Task 2.6: Status of database of absolute gravity measurements
Was already covered under TOP 1.
7 Task 2.7: Structure of information to be collected, status of
what is available, further progress
Coskun Demir
presented an overview of the status for this
task (see
ppt
).
8 Summary of Action Items
Action Item
WP2-3-1:
Richard Bingley
to initiate that requirements for AG sites are explicitly
written down. This task should be carried out in the frame of the
ESEAS TEC.
Responsible:
Richard Bingley,
Deadline:
31 August 2004.
Rational:
Clear requirements for AG sites should be made available on the ESEAS
web page to aid ESEAS members in case they want to upgrade a ESEAS Observing
Site for AG measurements.
Action Item
WP2-3-2:
Halfdan Pascal Kierulf
to organise a new analysis test comparison with CGPS data for
Jan 2000 to present from approx. five
stations.
Responsible:
Halfdan Pascal Kierulf,
Deadline:
15 April 2004.
Rational:
This experiment is done in order to check whether older
IGS products are of sufficient quality to create
ESEAS time series. At least GIPSY PPP and Bernese network
solution should be compared, but preferably
all ACs should participate. It could also be worthwhile
to process all data for approx. five stations from
Jan 2000 to present, since this would give a chance to
determine and compare long-term rates.
Action Item
WP2-3-3:
Richard Bingley
and
Halfdan Pascal Kierulf
together with
TS,
to select five stations
for the test in AI WP2-3-2, which are also processed by TIGA.
Responsible:
Richard Bingley,
Deadline:
15 March 2004.
Action Item
WP2-3-4:
Hans-Peter Plag
to send out the Master files for GPS site documentation
to the GPS analysis groups for comments.
Responsible:
Hans-Peter Plag,
Deadline:
28 February 2004.
Action Item
WP2-3-5:
Halfdan Pascal Kierulf
to send out the ESEAS Time series files for
comments.
Responsible:
Halfdan Pascal Kierulf,
Deadline:
28 February 2004.
9 Date and place for the next meeting
The next PT meeting in May 2004 will review the status of WP2 and
decide whether another meeting is needed prior to the
workshop in November 2004.
The meeting was closed by
Hans-Peter Plag
at 13:00.
End of Minutes