Radar Altimetry Tutorial and Toolbox Newsletter #2


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Radar Altimetry Tutorial and Toolbox Newsletter #2 June 2017

Dear subscriber,

Welcome to the second newsletter from the Radar Altimetry Tutorial and Toolbox website, where we bring you the latest developments of the toolbox and tutorial for the Altimetry Scientific Community and everyone interested in learning about altimetry and its applications.



BRAT @ Living Planet 2016

 The Broadview Altimetry Toolbox will be at the ESA Living Planet Symposium 2016 in Prague (http://lps16.esa.int/index.php). There we will unveil the new toolbox (still in its beta version) and give a first taste of its potential.

You can check out the new functionalities at the session Toolboxes 1, on the 2nd day at 9:00, in South Hall III (http://lps16.esa.int/page_session26.php#155p), or at the EO Science Stand demonstration, at 9:45 of the last day, in the Exhibitors Area.

Please come and visit us!


New Version of BRAT Released


The Broadview Radar Altimetry Toolbox is a tool designed to use radar altimetry data. It is available in 32-bit and 64-bit versions for Windows, Mac OS X and Linux (Debian 7). The Broadview Radar Altimetry Tutorial and Toolbox is a joint project between ESA and CNES to develop an open source tool (LGPL-3) freely available to all the altimetry community.

The toolbox is able to:

• read all altimetry data from official data centres, from ERS-1 and 2, Topex/Poseidon, Geosat Follow-on, Jason-1, Envisat, Jason-2, Cryosat and Sentinel-3, from Sensor Geophysical Data Record to gridded merged data

• process and manipulate altimetry data

• visualise the results

Current Release

The current version of the Broadview Radar Altimetry Toolbox is v4.0.0 (beta), and will be released during the LPS’16 in May and available at our website for download (http://www.altimetry.info/toolbox/).

The following improvements have been added to BRAT :

• Support for inclusion of user’s Python 3.x scripts in data expressions via the GUI

• Complete redesign of the GUI, with flexibility and ease of use in mind

• Addition of Quick operations simplifying the operations

• More intuitive and interactive plots, maps display

• KML export improvements

• Addition of histogram plots


New SAR Altimetry Tutorial

The Delay Doppler/SAR altimeter differs from a conventional radar altimeter in that it exploits coherent processing of groups of transmitted pulses. It is not pulse-limited like classical radar altimeters, so the full Doppler bandwidth is exploited to make the most efficient use of the power reflected from the surface.
Delay Doppler/SAR altimeter “stares” at each resolved along-track cell as the radar passes overhead for as long as that particular cell is illuminated. Note that each cell is viewed over a larger fraction of the antenna beam than the pulse-limited; thus more data is gathered, which leads to substantial benefits (e.g. it uses most of the power received).
The Delay Doppler/SAR altimetry processes the data such that they could be seen as having been acquired from a synthetic aperture antenna. This along track processing increases resolution and offers a multilook processing with the two independent dimensions: along-track and across-track (range).

The Delay Doppler/SAR mode altimeter offers many potential improvements over conventional altimetry for measurements over the oceans, coastal zones and inland waters using retrackers adapted to the specific nature of Delay Doppler/SAR altimeter echoes.
Cryosat-2 operates a Delay Doppler/SAR mode altimeter, and the recently launched Sentinel-3 mission has SAR for nominal mode of acquisition.

The Altimetry Tutorial has been expanded, now including a new section solely dedicated to this new mode of altimeter operation (http://www.altimetry.info/radar-altimetry-tutorial/sar-tutorial/).


Upcoming Events

• Official Release of version 4.0.0 foreseen for mid July 2016

• Poster presentation of the official release at COSPAR 2016 at the end of July, with DVD handouts

• BRAT plans to be present at the OSTST/COASTAL 2016 at the beginning of November


Altimetry Forum

Check the altimetry Forum to post your questions and experiences at http://www.altimetry.info/forums.