This website uses cookies. By continuing to use this website you are agreeing to our use of cookies. 


Latest Data Update: 2023-04-14
Status: Ongoing
Online Status: ONLINE
Publication State: Published
Publication Date: 2022-11-15
Download Stats: last 12 months
Dataset Size: 7.74M Files | 66TB


This dataset contains Interferometric Synthetic Aperture Radar (InSAR) products generated by Looking inside the Continents from Space Synthetic Aperture Radar (LiCSAR) from Centre for the Observation and Modelling of Earthquakes, Volcanoes and Tectonics (COMET). Interferograms and coherence maps have been produced automatically using the LiCSAR processor, which builds on the Gamma SAR and Interferometry software. Interferograms have been processed in overlapping “frames” defined within COMET-LiCS.

The basic products are given in the list below:

• This is the coherence image of the interferometric pair. The values vary between 0-255 in which 0 refers to the lowest coherence values and 255 indicates the highest values of coherence.

• geo.diff_pha.tif: The wrapped phase image in radian. The values vary within the range of -3.14 to 3.14. These are differential phases as the topographic correction has already been applied using 1 arc-second SRTM DEM data.

• geo.unw.tif: This is the unwrapped phase image in radian. The unwrapping is performed using SNAPHU. The zero values in the unwrapped file refer to the pixels which are masked out due to the low coherence.

All products are georeferenced to WGS-84 geographic coordinate system.

LiCSAR products are categorised into 175 folders which correspond to the Sentinel-1 175 orbits per cycle which are the same for both Sentinel-1A and Sentinel-1B. In the next level, the frames are defined. The frames are slices that refer to the same point temporally and geographically. The name of each frame (OOOP_AAAAA_BBBBBB) consists of 3 parts: in the first part, the three digits OOO denotes the orbit number while P shows whether it is descending (D) or ascending (A). The next part i.e. AAAAA shows the geographic location of the frame. Finally, the last part BBBBBB identifies the number of bursts where the first, second and third digit pairs identify the number of bursts in the first, second and third sub-swath respectively.

The LiCSAR processing is currently generating 3 connections per epoch. This means that for each epoch there are 3 interferometric pairs generated using the next 3 chronological acquisitions.

Please also include the following acknowledgement and citations when using LiCSAR data:

Acknowledgement: “LiCSAR contains modified Copernicus Sentinel data [Year of data used] analysed by the Centre for the Observation and Modelling of Earthquakes, Volcanoes and Tectonics (COMET). LiCSAR uses JASMIN, the UK’s collaborative data analysis environment (”

Citable as:  Lazecky, M.; Maghsoudi, Y. (2022): LiCSAR interferometry products. NERC EDS Centre for Environmental Data Analysis, date of citation.
Abbreviation: Not defined
Keywords: COMET, Sentinel 1


Previous Info:
No news update for this record
Previously used record identifiers:
No related previous identifiers.
Access rules:
Access to these data is available to any registered CEDA user. Please Login or Register for an account to gain access.
Use of these data is covered by the following licence: When using these data you must cite them correctly using the citation given on the CEDA Data Catalogue record.
Data lineage:

Data were produced by the project team and supplied for archiving at the Centre for Environmental Data Analysis (CEDA).

Data Quality:
Data are as given by the data provider, no quality control has been performed by the Centre for Environmental Data Analysis (CEDA).
File Format:
Data are supplied in Tiff format with corresponding .png image

Process overview

This dataset was generated by a combination of instruments deployed on platforms and computations as detailed below.

Instrument/Platform pairings

Sentinel 1 Synthetic Aperture Radar (SAR) Deployed on: Sentinel 1A

Instrument/Platform pairings

Sentinel 1 Synthetic Aperture Radar (SAR) Deployed on: Sentinel 1B

Computation Element: 1

Title LiCSAR processing
Abstract COMET LiCSAR processing using Gamma SAR and Interferometry software on Sentinel 1 IW SLC products. For the details of the LiCSAR methodology [LiCSAR: An Automatic InSAR Tool for Monitoring Tectonic and Volcanic Activities paper in the docs tab]. In summary, once a new acquisition arrives, it is logically decomposed into pre-defined burst units and registered in the LiCSInfo database that handles burst and frame definitions. Images including bursts that form a given frame are extracted and merged into frame images. These are coregistered towards a primary frame image (a master image) that was set during the initialization of a frame, beforehand. The coregistration process includes spectral diversity and other necessary corrections. Once coregistered, the interferograms are formed by combining the new image with three chronologically previous ones. This way is suitable for interpretation and for further use of the interferograms in multitemporal InSAR processing methods based on small baselines strategy (e.g. NSBAS approach currently implemented into custom LiCSBAS chain [ LiCSBAS: An Open-Source InSAR Time Series Analysis Package Integrated with the LiCSAR Automated Sentinel-1 InSAR Processor paper in the docs tab]). The interferogram unwrapping is performed using optimised SNAPHU approach. All the LiCSAR products are multilooked by factors of 5 in the range and 20 in the azimuth directions to achieve a resolution of around 100×100 m per pixel. LiCSAR processing chain consists of: 1. Preparation of Frame Epoch SLC 2. Resampling to RSLC 3. Formation of Differential Interferograms 4. Unwrapping Interferograms 5. LiCSInfo Metadata Database 6. LiCSAR FrameBatch Processing 7. FrameBatch Processing Chain 8. FrameBatch Post-Processing For more information please see the LiCSAR: An Automatic InSAR Tool for Monitoring Tectonic and Volcanic Activities paper in the docs tab.
Input Description None
Output Description None
Software Reference None
Output Description


Output Description


  • var_id: grid_mapping
  • var_id: x
  • long_name: x
  • var_id: y
  • long_name: y
  • var_id: z
  • long_name: z

Co-ordinate Variables

  • units: degrees_north
  • long_name: latitude
  • var_id: lat
  • standard_name: latitude
  • long_name: longitude
  • standard_name: longitude
  • units: degrees_east
  • var_id: lon
Temporal Range
Start time:
End time:
Geographic Extent