Hello again, Mark -

You hit it exactly on the head - You have to remember that most earlier proposals (anything before the UK NEO Task Force Report) were indeed made by astronomers - and these astronomers had been working with $0 dollar budgets for a long long time - some for as long as 20 years. When they had humbly begged for a few pennies, they had been largely ignored -
On the other hand, my background was in manned systems, where expenditures on the order of $10's of billions of dollars were and are quite common - for example, there's a quite vocal group of "space cases" here in the US who think that NASA should do nothing more than spend $28 billion on something as relatively useless as sending a few people to Mars -
So the first part of my solution was determining that these astronomers had not been asking too much, it was rather that they had been asking for too little -

Also, and this was a few years back, few of the astronomers here in the US were aware of the danger of smaller impacts, (though this danger was widely known by UK astronomers), so they had been pleading for those pennies only for a system to find only the largest objects -
Again, my background was in historical studies (most recently of manned space systems), and when it became clear to me how bad the small impactor situation was, I simply threw at it the most powerful astronomical system I had ever heard of - the lunar based Planetary Detection System forwarded by several Presidential Science Advisors -
Based on Houston's performance of the 90 Day Study for Bush Snr, I assumed that they were simply incapable of coming up with an economical architecture for constructing the Planetary Detection System - and based on the experience gained over some 10 years in reverse engineering some 30 years of Soviet lunar projects I put together the architecture seen at

http://www.geocities.com/epgrondine

EP