GNSS for Severe Weather and Climate

Working Group 1

Advanced Processing Techniques

Chair: Jan Dousa (GOP)

co-Chair: Galina Dick (GFZ)
list of WG1-members

The main goals of the WG1 are defined in four main domains:

  • Coordinating the development of advanced tropospheric products in support of weather forecasting (ultra-fast products, asymmetry monitoring, tomography, multi constellation processing, new products)
  • Reprocessing and model assessment of consistent tropospheric products for climatology
  • Exploiting numerical weather data in precise GNSS positioning (mapping functions, a priori ZHD modelling, tropospheric gradients, tropospheric models for real-time positioning, parameter conversions)
  • Supporting transfer of knowledge, tools and data exchange for extending existing products (new ACs, new networks, etc.)
In order to coordinate such wide area, particular subgroups were established according to the specific activities based on the contributions of individual WG1 members. The following sub-groups, their goals and milestones were set up:

ASYM (Hugues Brenot)

Goal: optimise monitoring of tropospheric horizontal anisotropy using space geodetic techniques
  • correlation of gradients from space geodetic technique analysis and numerical weather models (Milestone 1)
  • study the impact of introducing gradients on ZTD values (Milestone 1)
  • comparison of strategies for gradient estimation procedures and verification (Milestone 2)
  • comparison of strategies for retrieving slant delays and accuracy of assessments (Milestone 2)
  • co-operation with TOMO, MODEL, GNSS, PPP, EVAL, RT/UR, REPRO, STUDY, and WG2 (requirements, feedback, benchmark)
  • benchmark – assessment of gradients, slant delays, strategies, software

BENCH (Michal Kačmařík)

Goal: design a common benchmark campaign for evaluations and inter-comparisons of individual solutions
  • inventory – data, contributions, specific requirements and interest of individual subWGs (Milestone 1)
  • benchmark design, planning and data collection (Milestone 1)
  • individual contributions to benchmark (Milestone 2)
  • results evaluation, feedback and interpretations (Milestone 3)
  • co-operation with almost all other sub-groups, WG2, WG3
  • benchmark – coordination, inquiry of interest, benchmark design, data collection, results evaluation

EVAL (Samuel Nahmani)

Goal: homogenise strategies for troposphere parameter evaluation and conversion
  • contribute to the methodology for parameter conversions with focus on NRT/RT aspects (Milestone 1)
  • evaluate quality of meteorological parameters from various sources including in-situ data (Milestone 1)
  • methodology for evaluation with external data sources including tropospheric ties (Milestone 2)
  • implement and evaluate conversions for RT/NRT (Milestone 2) co-operation with RT/UR, ASYM, GNSS, PPP; close co-operation with WG2 (inputs), WG3 (methodology)
  • benchmark – evaluation of conversion methods and external data source

GNSS (..., Ján Hefty)

Goal: development, integration and consistency check of multi-GNSS constellations (GPS, GLONASS, Galileo, BeiDou)
  • GLONASS integration (Milestone 1)
  • monitoring product support (orbit & clocks), precise models (PCV, …), systematic errors (Milestone 2)
  • optimal exploitation of new signals from multi-GNSS constellations and impact study (Milestone 2)
  • preparation for Galileo & BeiDou integration (Milestone 3)
  • co-operation with ASYM, TOMO, RT/UR, EVAL, WG2 (impact study etc.)
  • benchmark – assessment of consistency, impact study, standard evaluation procedure

MODEL (Florian Zus, Marcelo Santos)

Goal: advanced exploitation of NWM data in precise GNSS analyses
  • development of software to handle NWM data as source (Milestone 1)
  • development of augmentation models for real-time positioning (Milestone 1)
  • assessment/improvement concepts of mapping functions (Milestone 1)
  • modifications of software towards usage of external data/products from NWM (Milestone 2)
  • assessment of augmentation models and a priori values from NWM (Milestone 2)
  • assessment of various input data sets and impact of developed models (Milestone 2)
  • co-operation with REPRO, ASYM, PPP, GNSS, WG2
  • benchmark – assessment of external tropospheric products and geodetic solutions exploiting them

NEW (Karolina Szafranek, Nicholas Zinas)

Goal: support transfer of knowledge, data exchange for improving coverage of tropospheric products in Europe
  • inventory of interests/offers for exploiting new networks and setting new ACs (Milestone 1)
  • planning for efficient transfer of knowledge and support of data exchanges (Milestone 1)
  • support for specific tools, processing/strategy knowledge (Milestone 2) filling gaps via setting new analysis centres, external data processing (Milestone 2)
  • co-operation whenever needed for a specific area, projects – EUPOS, EUREF, EPOS, E-GVAP
  • benchmark – possible evaluation of new analysis centre developments

PPP (Pavel Václavovic, Pawel Wielgosz)

Goal: support of the exploitation of PPP in future tropospheric estimations
  • PPP software development & comparison (Milestone 1)
  • evaluation of IGS RTS orbit and clock products (Milestone 1)
  • assessment of IGS RTS in near real-time solutions (Milestone 2)
  • impact of ambiguity resolution on tropospheric estimates (Milestone 2)
  • monitoring/developing/consolidating products in support of PPP (orbit & clocks) (Milestone 2)
  • co-operation with RT/UR, ASYM, GNSS, NEW, EVAL, IGS

REPRO (Elmar Brockmann)

Goal: prepare the state-of-the-art of homogeneous tropospheric products for climate (1996-2013)
  • Repro2 production – European, regional, national, global (Milestone 1) assessment of GNSS models, strategies and products (Milestone 1)
  • refine strategies for climate applications, based on long-term study (Milestone 2)
  • co-operation with EVAL, GNSS, ASYM; in close co-operation with WG3 (evaluation, feedback)
  • benchmark – provide reference tropospheric products (EUREF benchmark planned)

    RT/UR (Norman Teferle)

    Goal: develop and assess ultra-fast tropospheric products suitable for nowcasting
    • development and assessment of real-time or sub-hourly tropospheric solutions (Milestone 1)
    • optimisation of the strategy according to the required timelines and accuracy (Milestone 2)
    • demonstration campaign for real-time (European & global)
    • co-operation with EVAL, GNSS, PPP, ASYM; in close co-operation with WG2 (requirements, feedback, benchmark)
    • benchmark – assessment of various strategies, software, simulated mode

    STUDY (Laurent Morel)

    Goal: identify and answer scientific questions in support of existing needs or future perspectives
    • new ways of use of GNSS data for environmental monitoring
    • other proposed studies or activities proposed in various individual contributions
    • co-operation with RT/UR, ASYM, GNSS, PPP, NEW

    TOMO (Witold Rohm)

    Goal: assess the potential of GNSS data to retrieve vertical and horizontal information with an optimal resolution
    • relation between GNSS network and vertical/horizontal resolution of tomographic retrievals (Milestone 1)
    • correlation of gradients from space geodetic technique analysis and numerical weather models (Milestone 1)
    • ingest of new slant delay observations in the tomography models (Milestone 2)
    • develop with RT/UR new products for nowcasting (vertical and horizontal WV fluxes) (Milestone 3)
    • technical improvement (Kalman filter, selection of data to avoid redundancy, ingestion of new parameters) co-operation with ASYM, MODEL, WG2, GNSS, RT/UR (data, comparisons, requirements)
    • benchmark – impact study of new observations, consistency check with NWP/RS, nowcasting products radar validation
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