I am embarrassed about how long it has been since I posted anything new here. One reason for my absence has been an offer I received to join the team at digital-geography.com. I have been blogging now and then over there on remote sensing/Earth observation. Why not try it out if you aren’t already familiar with the blog?
I’ve been rarely writing on geoNotes recently. Mostly work (and life) has interferred with blogging. If you want specifics it’s largely because my teaching has reached epic proportions.
Still, I have had time for some fun stuff. Last week I was at the 4th TanDEM-X Science Team Meeting at DLR, Germany. Three days of talks about processing TanDEM-X (TDM) data, helical orbits, baselines and the height of ambiguity: heaven!
If you aren’t familar with TDM there is an introduction on the DLR website here. If you want more detail about the mission and data I’d recommend the excellent description in the CoSSC description document. It is quite technical but readable.
The TDM mission is really innovative. Two satellites, TerraSAR-X and TanDEM-X, flying in formation as close as a few 10s of metres at times. The helical orbit allows the mission to collect data at varying baselines to support advanced interferometry. The satellites can both transmit and receive data meaning along track interferometry is supported, bi-static observations can be made, and all sorts of experimental synthetic aperture radar configurations can be tested. In the coming year the satellite orbits will be adjusted to permit huge baseline acquisitions (4 km separation between the satellites) to provide highly sensitive height measurements (for applications in snow, sea ice and vulcaonology for example).
TDM is setting the agenda for interferometric SAR. New techniques and algorithms are being developed using these data; lessons are being learned that will shape future operational missions. TDM will be followed by an L-band SAR constellation, TanDEM-L. More fun awaits!
The European Space Agency’s Earth Science Advisory Committee (ESAC) has recommended that BIOMASS be selected as the 7th Earth Explorer mission. The recommendation was conveyed in a letter from Prof. Volker Leibig, Director of Earth Observation Programmes to Lead Investigators and Mission Advisory Groups. The letter references the ground breaking provision of P-band spaceborne SAR data that Biomass offers. Crucially, Professor Leibig also notes that Biomass has the potential to evolve into an operational system: something that is particularly attractive in an Earth Explorer mission.
I am a little surprised at the ESAC recommendation, but rather pleased. Biomass has excellent potential to deliver key environmental data to decision makers and researchers. At a presentation today in Sweden Lars Ulander, a member of the Biomass team, showed the diverse products and approaches developed for Biomass: Polarimetric SAR (PolSAR), Polarimetric Interferometry (PolInSAR) and Tomographic SAR (TomoSAR). Prof. Ulander demonstrated that the Biomass mission has the potential to not only provide valuable data products but will also drive SAR technology and analysis forwards. Biomass has yet to achieve the precision the team has identified as a requirement for the system (resolving forest height to <4 m) but tests have yet to include TomoSAR which should improve accuracy. Whatismore, P-band SAR could prove to have valuable additional applications in ice sheet sounding and sub-surface terrestrial mapping (particularly in arid regions).
Whilst I think the selection of Biomass by ESA at their meeting in May would be justified I feel particular sympathy for our colleagues who designed the CoReH2O mission. Professor Helmut Rott and his colleagues created an excellent mission concept and demonstrated it’s potential. I can’t help feeling a CoReH2O launch in 2019 or 2020 would be the crowning achievement of Prof. Rott’s illustrious career; it is a shame ESA couldn’t support both SAR missions (no doubt PREMIER is equally worthy but I am unfamiliar with that mission).
The decision is still open but surely ESAC’s recommendation will be the deciding factor: we’ll find out in May.
Following a User Consultation Meeting, held in Graz in March, the decision on which candidate mission will be selected for the 7th Earth Explorer, approaches. ESA will make a decision in May according to ESA’s website.
The three missions are:
-Biomass, a P-band synthetic aperture radar (SAR) which will improve our ability to map forest biomass,
-CoReH2O, a dual-band SAR which aims to improve the quality of operational snow cover maps,
-PREMIER, a troposphere-stratosphere chemistry mission.
I’d be happy if either of the SAR systems were chosen. Biomass could be interesting for ice sheet studies, with deep penetration into glacier ice. CoReH2O offers interesting possibilities with X- and Ku-band SAR acquisitions. I wonder though if after Cryosat-1 and -2 there will be a decision against a further glaciology mission. That would leave biomass against PREMIER. With the demise of Envisat and with it the SCIAMACHY and MIPAS sensors that supported atmospheric chemistry and meteorology, there may be a movement towards PREMIER. We’ll find out in May.
Firstly, sorry for the long silence. Posts will be a little more sporadic now due to my workload.
Here’s something worth reading in the mean time:
David F.S. Portree, who must have surely earnt the nickname “sci-fi” has blogged a great piece at Wired.com about plans for an alternative lunar habitat, designed in the 1960s. I am something of a fan of Mr Portree’s work: he writes great articles on Space Exploration History that for me capture a sense of excitement, innovation and futurism. In this piece Mr Portree explains plans to use spent Saturn V boosters as habitats on the Moon. For me this evokes a pre-quel to Space 1999 ( a series I was much enamoured with as a child).
1. Create an Earth Observation program to develop new applications, services and markets.
2. Design a series of innovative satellites; a forward thinking system of systems.
3. Make these satellites central to your next research program.
4. Fall out with your friends over money making risking all of the above.
5. Air all your problems in public.
I’ve created some new lectures on prezi.com. There you’ll find:
The Fundamentals of Remote Sensing
Active Remote Sensing
Introduction to GIS
Introduktion till GIS (på Svenska)
Vegetation Mapping (using remote sensing)
GIS data structures and databases.
Course books: Jones and Vaughan, 2010. Remote sensing of vegetation
Heywood et al. 2008. Introduction to GIS