Point Product

Product Overview

The CryoTEMPO-EOLIS point product is a set of high quality CryoSat swath altimetry point data with uncertainty metrics applied. This product is designed to be user-friendly; for use by non-altimetry experts. Due to the high volume of data, the data has been split into tiles of 100x100km in size.

  • Platform & Acquisition: CryoSat-2 SARin mode
  • Geographic Coverage: Greenland Ice Sheeet, Antarctic Ice Sheet, Alaska, Western Canada & US, Arctic Canada, Iceland, Svalbard, Scandinavia, Russian Arctic, Asia, Central Europe, Low Latitudes, Southern Andes, New Zealand, Antarctic Periphery and Antarctic Ice Shelves. 
  • Temporal Coverage – Baseline 2: from January 2010 for all regions except Western Canada & US Scandinavia, Central Europe, Low Latitudes, New Zealand (available from December 2023) and Antarctic Ice Shelves (available from April 2024).For all regions, the most recent data is available from 2 months prior to the current month. 
  • Temporal Coverage – previous Baseline (1): from July 2010 for Greenland and Antarctica, from July 2021 for Iceland, Svalbard, Canadian Arctic, Russian Arctic, Alaska and Southern Andes, and from October 2021 for Asia
  • Temporal Resolution: Monthly
  • Data Format: NetCDF
  • Data Contributors: Noel Gourmelen, Livia Jakob, Carolyn Michael, Martin Ewart, Jerome Bouffard, Alessandro Di Bella, Sophie Dubber, Andrea Incatasciato, Jonathan Alford, Tristan Goss, Oskar Fraser-Krauss
  • Cite As:

    Data over glaciers – “EOLIS elevation data generated using swath processing of CryoSat-2 data (Jakob & Gourmelen, 2023) and provided by the ESA CryoTEMPO project (https://cryotempo-eolis.org/).”

    Jakob, L., and Gourmelen, N., (2023). Glacier Mass Loss Between 2010 and 2020 Dominated by Atmospheric Forcing. Geophysical Research Letters 50(8), 1–10. doi:10.1029/2023GL102954

    Data over ice sheets and ice shelves – “EOLIS elevation data generated using swath processing of CryoSat-2 data (Gourmelen et al., 2018) and provided by the ESA CryoTEMPO project (https://cryotempo-eolis.org/).”

    Gourmelen, N., Escorihuela, M., Shepherd, A., Foresta, L., Muir, A., Garcia-Mondejar, A., Roca, M., Baker, S., & Drinkwater, M. R. (2018). CryoSat-2 swath interferometric altimetry for mapping ice elevation and elevation change. Advances in Space Research, 62(6), 1226-1242. https://doi.org/10.1016/j.asr.2017.11.014

Data Attributes

The point product contains the following variables:

  • time (time in seconds)
  • x (geographic coordinate) or lon (degrees)
  • y (geographic coordinate) or lat (degrees)
  • elevation (metres)
  • uncertainty (metres)
  • is_swath (1 for Swath, 0 for POCA)
  • input_file_id (id of L1b and L2 underlying products)

Coordinate reference system: 

For Greenland, Iceland, Svalbard, Canadian Arctic, Russian Arctic, Alaska:

  • EPSG:3413 || +proj=stere +lat_0=90 +lat_ts=70 +lon_0=-45 +k=1 +x_0=0 +y_0=0 +datum=WGS84 +units=m +no_defs

For Antarctica:

  • EPSG:3031 || +proj=stere +lat_0=-90 +lat_ts=-71 +lon_0=0 +k=1 +x_0=0 +y_0=0 +datum=WGS84 +units=m +no_defs
For Southern Andes and Asia:
  •  EPSG:4326 || +proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs

For Scandinavia and Central Europe:

  • EPSG:3035 ||  +proj=laea +lat_0=52 +lon_0=10 +x_0=4321000 +y_0=3210000 +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +units=m +no_defs +type=crs

For Western Canada & US:

  • +proj=tcea +lon_0=-119.5 +datum=WGS84 +units=m +no_defs

For Low Latitudes:

  • +proj=tcea +lon_0=-73 +datum=WGS84 +units=m +no_defs

For New Zealand:

  • +proj=tcea +lon_0=172.5 +datum=WGS84 +units=m +no_defs

Documentation

Product Handbook:

The product handbook acts as a user guide and contains high level algorithm descriptions as well as an overview of file structure:

 

Download the Product Handbook

 

Algorithm Technical Baseline Document:

For more in-depth explanations of underlying algorithms, please refer the Algorithm Technical Baseline Document (ATBD):

 

Download the ATBD

Tutorials and Tools

The Demos & Tutorials page contains links to interactive python notebooks, that allow you to download and interactive with the EOLIS gridded product. 

Visit the EOLIS Tutorials page

Feedback and Queries

Feedback or questions about the CryoTEMPO-EOLIS Thematic Products is welcomed. Please use the following contact details:

E-mail: support@cryotempo-eolis.org

 

Or alternatively, get in touch using our Contact Form  

DOWNLOAD THE DATA

There are two ways to download the EOLIS point product: 1) directly from the ESA FTP server, or 2) from http://cs2eo.org, a geospatial-temporal query platform for earth observation data.

FTP Download:

Use the following link to access the ESA server and directly download any available point data.

The folder structure on the ESA Science Server is: TEMPO_SWATH_POINT/YYYY/MM/<ZONE>

The file naming convention is: CS_OFFL_THEM_POINT_<ZONE>_<YYYY>_<MM>_<X>_<Y>_<VERSION> where ZONE is the region name e.g. GREENLAND. Note that X and Y are polar coordinates.

Data tile locations: A Shapefile (.shp) containing the data tile locations is available in each monthly folder in tar file format: CS_OFFL_THEM_POINT_<ZONE>_<YYYY>_<MM>.tgz

ftp://science-pds.cryosat.esa.int/TEMPO_SWATH_POINT/

cs2eo.org:

 

 

The CryoTEMPO-EOLIS download service provided by cs2eo.org allows for interactive visualisation of available point product data. It provides a flexible, user-friendly service for querying the data, allowing you to:

    • Specifiy a query area using Lat/Long or a drawn polygon
    • Specifiy the start and end dates and times of your query
    • Immediately visualise the data coverage of the results of your query

To get started as new user, navigate to one of the Custom Query Examples shown below and explore the possiblities.

Go to cs2eo.org

Exploring the Point Product coverage on cs2eo.org