Mobile version

Experimental Sentinel 3 products (Peachi)

Types of dataset: Mono-mission Sentinel-3A altimetry product, LR-RMC mode. These products are produced by CLS in the framework of the Peachi project, funded by CNES.

Contents: Along-track level-2 estimations at 20Hz rate in LR-RMC mode. LR-RMC associated waveforms are also included, as well with the geophysical corrections applied to the altimeter range.

Use:  open ocean, coastal applications

Description: specific product generated using the innovative LR-RMC altimetry mode, more details about the processing mode below.
Users should keep in mind that these products are experimental products. Notably, they are not produced on an operational basis. They are freely distributed without any warranty of any kind.

Geographic coverage: Global coverage corresponding to Sentinel-3A spatial sampling

Format: NetCDF-CF

LR-RMC presentation

The Low-Resolution with Range Migration Correction (LR-RMC) mode is a newly ocean delay-Doppler altimetry processing, therefore applicable for CryoSat-2 & Sentinel-3 missions. The processing has been first designed and used by Thales Alenia Space for in-flight assessing of Cryosat-2 data [Phalippou et Demeestere, 2011]. It has then been revisited by Boy et al. [2017a] as one of the most promising altimeter data processing solution to deal with long ocean waves issues while keeping high delay/Doppler measurement capability in terms of precision.

The processing in a nutshell


Similarly to unfocused SAR altimetry, the LR-RMC method coherently combines radar pulses in a burst to create a set of Doppler beams. But, unlike it, the LR-RMC method then sums all the beams contained in a radar cycle (4 bursts of 64 beams for the open-burst Sentinel-3-mode altimeter) to build a 20-Hz multi-looked waveform. The resulting footprint is much larger than that of the unfocused SAR altimeter (and as large as the illuminated area in conventional altimetry) allowing a better spatial average of the surface elevation to mitigate long ocean wave effects.


The LR-RMC technic takes advantage of a number of similarities in processing with the unfocused SAR altimeter approach (as described in Boy et al. [2017b]), which made its implementation relatively straightforward. This is even made easier thank to major simplifications in the LR-RMC data processing scheme (no beam steering is needed and a shorter integration time is used to produce a mean multi-looked echo thus minimizing possible errors in alignment and echo beam stacking, but also limiting possible surface movement effects). Despite this time duration reduction, the number of beams is as high as in SAR altimeter mode processing (4x64 averaged beams compared to 256 averaged looks in SAR altimetry), thus providing a noise reduction at least as good as, or even better than in SAR mode.


LR-RMC benefits over open-ocean

The two years’ time series of Sentinel-3A LR-RMC data provided by AVISO have been deeply analyzed by CNES/CLS. The processing shows promising results in many aspects:

  • LR-RMC improves the measurement precision (SSH & SWH) compared to unfocused SAR-mode over ocean. Noise reduction is about 20% in average at 2.7m wave height
  • LR-RMC provides no-correlated errors as observed in LRM data, and makes some improvements in the detection of meso-scale structures compared to unfocused SAR-mode
  • LR-RMC brings stable performances whatever swell condition while unfocused SAR-mode is largely negatively impact

A presentation of the processing, from Boy et al. [2017a], at Miami OSTST 2017, is available here





Copyright : 2017- 2019

20 Hz product


Distribution media


Delivery delay

Data period

Data used

File weight



27 days

one shot

july 2016 - August 2018

One pass per file

36MB per pass file

Rss feedsContactPartnersFAQLexiconLegal noticePersonal Data Protection PolicyMobile
You must enable cookies in your browser preferences to save the modifications
You are using an older version of Internet Explorer, please update to take full advantage of Aviso+ features

Customize the home page

View all widgets
Reduce display
Public profile
User profile

Select/Deselect widgets

Discover AVISO+

Customizable home, reading tools, products search guide, etc.. Discover step by step the features of the new site AVISO+.

Customizable homepage

This home page is composed of blocks called "widgets".

Rearrange the blocks with a "Click & Drop".

Hide a widget with the cross at the top right. Reset or add a widget with the "wrench" icon. The "User" and "Public" profiles offer a predefined organization.

All the modifications are automatically saved as cookies on your machine so as to enable you to have your own specific AVISO+.

Reading tools

Ease your reading by choosing the page background colour (black/white) and/or by modifying the font size.

Browsing menu and breadcrum trail

To ease your browsing through AVISO+, you can use at any time the main banner items with the interactive submenus or use the browsing menu on the left side of the screen (it is open by default). For more readiness of the page contents, you can fold and unfold the browsing menu by clicking on the tab. At any time you can know where you are thanks to the browsing menu or the breadcrum at the top of the page.

Products search guide

The first submenu of the "Data" banner item leads you to a new search form enabling you to find quickier the product that suits your needs. The list of results is updated according to your selection criteria.

AVISO+ Multimedia

The first submenu of the "Multimedia" banner item leads you to AVISO+ collections of images and videos linked to altimetry and its applications. Have a nice visit!