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ERS-1/2 Radar Altimeter REAPER Sensor Geophysical Data Record - SGDR [ERS_ALT_2S]

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Fast Registration with Immediate Access (Open)

  1. Go to the ESA User Services Portal
  2. Register or log in to EO Sign In
  3. Fill in and submit the form for accessing the data
  4. You will receive an email with your user name
  5. A second email will follow with your password to download the data from the ftp server via an FTP client (see Read More for connection details) or, alternatively, from command line using L-FTP.
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The data can be downloaded via an FTP client (e.g., FileZilla or WinSCP) using the options "explicit FTP over TLS if available" or "Require explicit FTP over TLS". 

For further information about the EO Sign In Service you can visit TellUs.

Should you need support to access the data, please contact EOHelp.


This is a RA Geophysical Data Record (GDR) product containing radar range, orbital altitude, wind speed, wave height and water vapour from the ATSR/MWR as well as geophysical corrections.

The REAPER (REprocessing of Altimeter Products for ERS) product is generated by applying a similar processing as for Envisat RA-2 on the Level 1b consolidated waveforms using 4 different re-trackers, RA calibration improvement, new precise orbit solution (POD), new ionospheric corrections (NICO09 until 1998 and GIM up to 2003), ECMWF ERA-interim model and updated SSB tables.

This product contains two data rates: a low rate of 1 Hz and a high rate of 20 Hz.

Most 1 Hz data is also represented at 20 Hz, while microwave radiometer (ATSR/MWR) data and the atmospheric and geophysical corrections are only given at 1 Hz.

The REAPER GDR (ERS_ALT_2_) is a global product including data over ocean, ice and land.

It should be noted that this product differs from the Envisat RA2 in the following ways:

  • The product format; which is NetCDF (more details can be found in the Product Handbook, and not PDS
  • The product is delivered based on orbit acquisition and not per pass (pole-to-pole).

This product is extended through Envisat RA-2 data.



Digital Object Identifier (DOI):
Spatial coverage:
82 N, -82 S, -180 W, 180 E
Temporal coverage:
1991-08-03 - 2003-07-02REAPER ERS-1 data is available from 3 August 1991 to 2 June 1996 REAPER ERS-2 data is available from 14 May 1995 to 2 July 2003
Date of launch:
1995-04-21, 1991-07-17
Mission status:
Orbit height:
782 to 785 km
Orbit type:
Swath width:
5 km


Level 2


Utilisation of this data is subject to ESA's Earth Observation Terms and Conditions.



European Space Agency, 2014, ERS-1/2 Radar Altimeter REAPER Sensor Geophysical Data Record - SGDR [ERS_ALT_2S], Version 1.08.


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