[IGSMAIL-8039] IAG 2021 Scientific Assembly: Session 1.3 "Terrestrial and space geodetic ties for multi-technique combinations"

[Urs Hugentobler]

Dear Colleagues,

We would like to draw your attention to Session 1.3 "Terrestrial and 
space geodetic ties for multi-technique combinations" of the upcoming 
Scientific Assembly of the International Association of Geodesy, taking 
place as virtual meeting between June 28 - July 02, 2021.
Please consider to submit an abstract to this session. See 
http://www.iag2021.com/en/web/index/1646_140108__ 
<http://www.iag2021.com/en/web/index/1646_140108__> for this and other 
sessions of the Commission 1 Symposium.

Abstract submission deadline is *30th April, 2021*  
(http://www.iag2021.com/en/web/index/1646_802946__ 
<http://www.iag2021.com/en/web/index/1646_802946__>).

We are looking forward to your contributions. With apologies for 
cross-postings.

Best regards,
Urs Hugentobler, Krzysztof Sosnica, Weiping Jiang


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Session 1.3: Terrestrial and space geodetic ties for multi-technique 
combinations

Consistent combination of space geodetic techniques is a necessity for a 
full exploitation of the relative strength of the techniques for the 
generation of accurate and long-term stable geodetic products. Essential 
for this task are precise ties between the different techniques, 
co-located on ground and in space. This session aims at a review of the 
state-of-the art and outlook to future prospects as well as assessment 
of the impact on geodetic products of precision sight surveys, 
monitoring of temporal variations of tie vectors, identification of 
technique-specific biases, space geodetic combination methodologies, but 
also of using additional and novel tie information such as intra- and 
inter-technique tropospheric ties or ties realized through common clock 
parameters at geodetic observatories, as well as exploitation of already 
existing space ties such as SLR observations of GNSS satellites, 
experiments of observing GNSS satellites with VLBI, and simulations of 
the impact and benefit of future space co-location missions.
The following topics are of specific importance:
* Identification of technique-specific biases.
* Temporal variations of tie vectors at co-located stations.
* Intra- and inter-technique ties based on tropospheric parameters and 
common clock parameters.
* Space-based ties using GNSS-satellite tracking via SLR or VLBI 
measurements.

Keywords: Terrestrial/space geodetic ties, terrestrial reference frames, 
multi-technique combination, local tie vectors, co-located techniques, 
tropospheric parameters, SLR-to-GPS tracking.
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