The current status of the HI simulation efforts is presented, in which a self
consistent simulation path is described and basic equations to calculate array
sensitivities are given. There is a summary of the SKA Design Study (SKADS) sky
simulation and a method for implementing it into the array simulator is
presented. A short overview of HI sensitivity requirements is discussed and
expected results for a simulated HI survey are presented.Comment: 7 pages, 6 figues, need skads2009.cls file to late
