Smos is operating at L Band in a protected window i.e., 1400-1427 MHz. This means that emission are FORBIDDEN in this wave band.Never the less, as some “people ” are careless, selfish etc, they do not bother and tend to spill into the protected band (by being very close and not filtering adequately) so for SMOS we only use a limited part of the allocated frequency band reducing the sensitivity (as usual the selfishness of a few is detrimental to many!)So that is a nuisance but we can deal with it.But some are more naughty. They do not bother about harmonics (700 MHz UHF TV band for instance) and do have thus illegal emission in the protected band. They can cause severe problems at ground levelThe most noxious and nasty are those who deliberately emit (and usually with huge power) in the protected band….The first SMOS data give an idea of those polluters and threat to all the potential and useful applications of L band data The map below provided by the L1PP team at ESAC shows in red all the potential large illegal emitters.We are working on the data and will either better focus in some cases (as soon as the sources are better identified) as already done for many, and suppress the “tails”, as well as get rid of any potential artifact. Once all is validated we will publish the map. and start considering more potent actions towards the relevant organizations.In the mean time you can see that some areas are – with the current algorithms – totally beyond reach for SM retrievals.
