I assume they're not unknown to science as they're pretty prominent, but then again they're not marked on the Ordnance Survey map as such things tend to be, like the Roman Camps just to their north west for example (http://streetmap.co.uk/grid/375689_566022_120).
Whatever they are they are fairly visible in Bing Aerial view (NB I used Bing as they have OS 1:25,000 maps).
Edit: Speaking of things not being on OS maps - I've noticed that over the last ~40 years (since I started looking at OS maps at an early age) that they show far less historical details than they used to. I don't know if this is policy to keep maps less cluttered or because many things in agricultural areas simply have been ploughed over so many times that nothing remains. A shame either way.
They do appear as "Roman camp" on an OS at the right scale - try the website, where you can sign up for free for a week. Or the Heritage Gateway website mentioned by ascorbic.
There's a lot in the area that's still to be dug. It's a matter of finding the money to fund digs.
I assume they're not unknown to science as they're pretty prominent, but then again they're not marked on the Ordnance Survey map as such things tend to be, like the Roman Camps just to their north west for example (http://streetmap.co.uk/grid/375689_566022_120).
Any archaeologists in the house?