code: def footprint(self,nside):
          
          import healpy
          import ugali.utils.projector
          if nside > 2**9: raise Exception("Overflow error: nside must be <=2**9")
          pix = np.arange(healpy.nside2npix(nside),dtype='int')
          footprint = np.zeros(healpy.nside2npix(nside),dtype='bool')
          ra,dec = ugali.utils.projector.pixToAng(nside,pix)
          table_name = 'Pix%i'%nside
          self.upload(np.array([pix,ra,dec]).T, ['pix','ra','dec'], name=table_name)
          radius = healpy.nside2resol(nside_superpix,arcmin=True)
  
          query="""
          SELECT t.pix, dbo.fInFootprintEq(t.ra, t.dec, %g)
          FROM %s AS t
          """%(radius, table_name)
docs: Download the survey footprint for HEALpix pixels.