Day 1 - Fringe Workshop Programme, 1st December
Day 2 - Fringe Workshop Programme, 2nd December
Day 3 - Fringe Workshop Programme, 3rd December
Day 4 - Fringe Workshop Programme, 4th December
Day 5 - Fringe Workshop Programme, 5th December
Conference Photos

FRINGE Seed Questions

Session: Tectonics

  1. InSAR techniques provide a wealth of data on tectonic events that cannot be feasibly obtained through traditional measurements; is it possible to quantify the benefit, in human or financial terms, of the resulting improved knowledge of underlying geophysical mechanisms?
  2. What are the smallest tectonic signals that can be measured reliably, co-seismic, interseismic, and aseismic?
  3. Can measurements of atmospheric water vapor variations, such as by MERIS, accurately correct for the path delay in interferograms of areas with great topographic relief?
  4. How can non-tectonic deformation effects, such as ground subsidence, be separated from tectonic deformation?
  5. What improvements on tectonic measurements can be made with multiple incidence angles and both ascending and descending tracks?

Session:  Land Motion

  1. Do the available InSAR products on land motion fulfill the needs of the hazard protection and geotechnical engineering communities?
  2. What is the status of methods for InSAR motion mapping and which methodological developments would help to improve land motion products?
  3. How better merge INSAR products with ground based observations (GPS, leveling, tacheometry etc.), and other spatial products (optical correlation etc.)?
  4. Which measures can be taken to foster the utilization of Envisat ASAR for land motion monitoring?
  5. What is the preferred sensor configuration for land motion services (SAR frequency, repeat cycle, spatial resolution, look angle, polarization etc.)?
  6. Which actions are needed to guarantee long-term continuity for InSAR monitoring of landslides and seismic deformation?

Session: Methodology and Techniques:ERS/Envisat Interferometry

  1. Are there techniques / experiments to predict/model the atmospheric phase screen by means of different sensors (Meris, etc.)?
  2. Can the tropospheric water vapor contribution to interferograms be reliably corrected and what are the best methods?
  3. How should we model uncorrected errors in InSAR data?
  4. What is the best method for constructing a deformation time series from InSAR?
  5. What's the contribution of Envisat polarimetry in interferometry, DEM generation etc.?
  6. Can the persistent scatterers technique be used to detect small deformation signals, such as interseismic strain across active faults, in remote parts of the world where there few man-made structures to act as corner reflectors?
  7. How do public domain and/or open source InSAR tools compare to commercial packages?

Session:  DEMs

  1. Which surface is represented by a microwave DEM?
  2. Temporal decorrelation in the repeat-pass case and volume decorrelation in the single-pass case are limiting factors in high-resolution DEM generation. What would be the optimum system parameters (frequency, polarization, resolution, orbit etc.) for DEM generation in the:
    • single-pass case?
    • repeat-pass case?
  3. Has INSAR DEM generation reached operational status? For which type of applications microwaves DEMs are preferable/comparable to those generated with other techniques (e.g. flooding, telecommunications, military, urban, road and pipelines track planning etc.)?
  4. A DEM generated from multi-pass satellite SAR interferometry is affected by atmospheric artifacts and low wavenumber errors induced by orbital inaccuracies: they can be partially compensated in many ways (Permanent Scatterers, Corner Reflectors, CATs, reference DEM, GPS etc.). What is the current state of the art?
  5. A way to cope with atmospheric artifacts is to try avoiding them by appropriate data selection.
    • What are the main ancillary data to be taken into account to perform SAR scene selection?
    • Are these ancillary information adequately and easily available?
    • Should these data be added to information systems like the EOLI catalogue?
  6. What kind of sensor should be added to future SAR missions in order to get the required information for proper SAR data selection?
  7. Which is the best strategy to gain coherence with single antenna satellite SAR systems (e.g. lower frequencies, multiple polarizations, shorter revisiting times etc.)?
  8. Which part of the ERS tandem archives has been exploited to generate/refine DEMs? Which is the average cost per square kilometer?
  9. How frequently should a DEM be updated? Is ENVISAT suitable for DEM updating (35 days revisiting time)?

Session: Longterm DINSAR

  1. What are the current and future most frequent and most promising applications for:
    • Peristent Scatterer DInSAR
    • "classical" long-term DInSAR?
  2. What are the major current deficits of the two methods mentioned before and how should they be remedied?
  3. Which other data types (meteorological, land cover, etc.) are required routinely to support long-term differential interferometry and to increase its rage of applicability and its accuracy?
  4. Different types of surfaces (water, snow, ice, fields, forests, sandy or rocky deserts, towns) have different dynamics and roughness: - Which tools are best for a meaningful description of their motion (microwave or lidar altimetry, SAR interferometry, GPS, optical levelling, etc.)?
    • Is there any use for more accurate, sub-millimetric measurements?
    • Should we push for higher frequencies?
    • Is there optimum polarizarion?
    • Lower frequencies will better penetrate vegetation reducing motion accuracy; where do we need that?
    • What is the reasonable revisiting rate we should ask for? (daily, biweekly, weekly, bimonthly, etc.)
  5. Do we know the long-term behavior of artificial scatterers like CR's or CAT's?
  6. Is it possible to combine and use scatterers that are not coherent for the long term?
  7. We could in principle temporally combine data from multiple platforms: where would this be an advantage?
  8. What would an optimum SAR system for long-term differential interferometry look like?

Session: Thematic Mapping

  1. What are the most promising thematic mapping applications of:
    • C-band InSAR?
    • L-band InSAR?
    • X-band InSAR?
  2. Which are the primary obstacles for InSAR to become an operationally applied tool for thematic mapping?
  3. Is temporal decorrelation understood sufficiently to be interpreted quantitatively?
    • How can present limitations due to temporal decorrelation be overcome?
    • What would be the optimal revisit time (temporal baseline)?
  4. Which radar wavelength provides the best overall compromise for different applications of InSAR?
  5. Do current InSAR applications fully exploit the information content in the data?
  6. What future mission extensions (multi-frequency, multi-incidence angles, multi-polarization) would be most useful for thematic mapping?


  1. Inversions of InSAR-measured deformation at many volcanoes have relied heavily on Mogi models. Does this reflect on the quality of the data, the nature of the volcanic pressure sources or some other factor?
  2. To what extent is the increasingly complex picture emerging from the InSAR-measured deformation at Etna - reservoir pressurisation, shallow gravity spreading, tectonic coupling - likely to be found elsewhere?
  3. What are the temporal samplings that are needed by InSAR missions to adequately address issues related to volcano deformation?
    • what is required based on volcanic processes themselves?
    • what is required as a means of reducing effects such as atmospheric noise?
  4. How much do we need the full 3D motion vectors from volcano InSAR in any future radar system? Will one ascending plus one descending pass do?
  5. Are classical DInSAR and peristent scatterer DInSAR techniques complementary on volcanoes?
  6. If we had to choose either C-band or L-band for operational InSAR monitoring of volcanoes, which would it be?
  7. Can general recommendations be given about how to combine InSAR and conventional observations on volcanic areas?

Session: Ice Motion

  1. Can ice velocity snapshots illuminate glaciological processes?
  2. For users of InSAR data it is important to know the accuracy of the measurements. Which qualitative error characteristics are needed?
    • what can InSAR presently provide?
  3. What are your experiences with longer than 1- or 3-days datasets? They have the potential to improve accuracy, but can they be used
    interferometrically and under what conditions?
    • in which areas are ENVISAT InSAR expected to work?
  4. Is operational monitoring of small ice bodies viable?
  5. How might other missions benefit ERS InSAR glaciology - e.g. ENVISAT, SRTM, PALSAR, CryoSat?
  6. ERS and ENVISAT were not designed specifically for repeat pass interferometry. How shall key design parameters be optimized to ice flow applications if a future dedicated interferometric SAR mission is decided? Key parameters include: frequency, repeat cycle, look angle, swath-width, resolution, polarization, auxiliary instruments etc.
  7. How mature is the use of interferometric data for snow accumulation mapping?
  8. Is interannual variability in snow conditions being correctly addressed as a source of error in repeat pass inteferometry of dynamic ice streams and margins.
  9. Is the ScanSAR mode of interferometry appropriate for ice sheet velocity mapping on a broad scale on a regular basis? What are the limitations?.
  10. How might the InSAR community grow?


  Higher level                 Last modified: 10-Feb-2010