Thanks, that is helpful. I can see from it there's lots of plane traffic flying just south of the river, from East to West, into Heathrow airport, from 5am onwards.
I'm often awoken by aviation flying over South East London at 6AM in the morning. This might be a good thing to look at during those times...
(I wear earplugs and have double glazing, but the noise is deep and penetrating. I wonder how many other hundreds of thousands of people are also disturbed by early morning planes...)