They are the consensus opinion of people who have studied both the cratering record of the Moon, estimated the number of NEO's, and done orbital simulations. In total two basically independent methods based on fairly hard evidence as opposed to interpreting every mythological disaster as an impact rather than the far more common earthquake or volcano.

Impact estimates are not even relevant to the point. The rate of impacts has nothing to do with the most cost effective method of detecting potential impactors unless they occur on intervals comparable to the potential detection period. They do not even by your screwball frequency estimates which have not been accepted in any peer reviewed process. Cost effectiveness is determined by a combination of dollars spent and survey completeness accompanied by some consideration of speed. It is not cost effective to spend 10 to 100 times more to gain a few perentage points in completeness at a slightly earlier date.

The fact that you raise this irrelevant issue and attempt to slander those doing real work in the field once again demonstrates why you far more of a hindrance than a help in addressing the impact issue and why you are despised by those doing the real work. You do nothing but lower the crediblity of the issue and hinder those doing the real work to gain funding and run the programs needed.

I have provided links to the actual <a href=http://rasc.larc.nasa.gov/rasc_new/CAPS/CAPS_Concept_Summary.pdf">; CAPS Summary site many times which clearly indicates that even its authors acknowlege a lunar detection system can not be justified on a stand alone basis as clearly indicated by the excerpts here. They are clearly considering an orbital system as well even by the link you provide. Your basic dishonesty on this issue is evidenced by your dredging up some presentation not linked at the main caps site which does not state what is clearly stated at the CAPS site.

Regards,
Mark