Envisat & ERS-2 formation flying

The two ESA missions currently carrying SAR (Synthetic Aperture Radar) instruments have once again been put into a tandem orbit. Effectively this means that ERS-2 and Envisat SAR instruments will image the same bit of the Earth with a separation of only 28 minutes.

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This tandem mission concept has happened previously with ERS-1 and ERS-2 and more recently between ERS-2 and Envisat. The current pairing will last from November 2008 until late January 2009. There are big advantages with the resulting data when using interferometric techniques over fast changing surfaces – including ice and snow covered areas.

More information from ESA here and let me know if you think you would like to access the data and I can help you jump through the ESA hoops if needs be.

CEOS handbook

CEOS (Committee on Earth Observation Satellites) has published the Earth Observation Handbook. This is an on-line reference book produced by ESA on behalf of CEOS listing current missions and instruments. It’s available here.

I haven’t waded through all of it yet, but given the climate change theme to this edition, there’s lots of ‘satellites are great for climate monitoring type’ info and examples. Perhaps I’ll highlight some of these later.

However the two immediately useful bits are as follows. Firstly the section covering the capabilities of Earth observation satellites. This is a useful entry point if you are looking for satellite capability in a particular topic. So you want to know what satellites can measure atmospheric chemistry? – then choose that section for an overview of what’s possible and what satellites are either available or planned.

The other useful section is the timeline database. A simple interface that allows you to see which satellites measure which parameters for what period. Simply construct a query to find out which current and planned satellites will measure, for example aerosols, for your period of choice.

The Wilkins waiting game

Back in March 2008 the Wilkins became the latest ice shelf to show signs of collapse. There was much interest and coverage then but it stubbornly hung on and most of it still remains ‘hanging by a thread’.

Since then the winter sea ice has effectively locked it in and there has been little change in recent months. Now in early austral summer with the sea ice retreating, there appear to be further changes. ESA have been keeping a close eye with almost daily Envisat SAR image acquisitions and folks at Münster University have spotted new rifts forming. So now everybody waits with baited breath for its demise and no doubt there will be further news releases when that happens. Of course it’s unlikely to all go at once and it is the dramatic bridge to Charcot Island that everyone expects to break first.

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We’ll be keeping an eye ourselves since we have access to all the Envisat imagery in near real time. So don’t worry – you won’t miss a thing!