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R. Jedicke (Lunar & Planetary Laboratory), A. Morbidelli (Obs. de la Cote d'Azur), T. Spahr (Smithsonian Astrophysical Observatory), J-M. Petit (Obs. de la Cote d'Azur), B. Bottke (Southwest Research Institute)
Using our model of the debiased orbital and absolute magnitude distribution of Near Earth Objects (NEO) (Bottke et al. 2001, Icarus, accepted), we have simulated the efficiency of various surveying strategies. To check the fidelity of our model and simulation we have calculated the number of NEOs with H<18 that the Catalina Sky Survey (CSS) should have detected in a nine-month observing period. The CSS detected 38 NEOs (2 Atens, 21 Apollos 15 Amors) while we predict that they should have found 28±5 NEOs (1.5±1.2 Atens, 17.3±4.5 Apollos, 9.1±3.3 Amors). Taking into consideration the difficulties in parameterizing the CSS asteroid rejection system, we believe our model is reliable and that it can be used to simulate the discovery efficiency of existing and virtual surveys.
Our main results are the following: (i) the LINEAR-like survey to a limiting magnitude of 18.5 can not fulfill the NASA goal of finding 90% of NEOs with H<18 by 2008. Only 60-70% of these bodies will be found (current completeness being ~45%). (ii) the system performance is not much better if restricted to the sub-categories of NEOS with the largest collision probability with the Earth or the smallest MOIDs (iii) a LINEAR-like survey with limiting magnitude ~21.5 could fulfill the NASA goal while the proposed LSST survey will be extremely effective. (iv) the determining factor in a survey's success is its limiting magnitude. The latitude of the observatory and the `NEO rate cut' do not significantly reduce the overall performance. (v) a dedicated survey from a satellite orbiting the Sun from the distance of Mercury would be extremely effective, especially for discovering NEOs with the smallest MOID. Even a survey with a limiting magnitude equal to 18.5 would discover 90% of the NEOs in just a few years.