Dusty, starforming galaxies and active galactic nuclei that contribute to the
integrated background intensity at far-infrared wavelengths trace the
large-scale structure. Below the point source detection limit, correlations in
the large-scale structure lead to clustered anisotropies in the unresolved
component of the far-infrared background (FIRB). The angular power spectrum of
the FIRB anisotropies could be measured in large-area surveys with the Spectral
and Photometric Imaging Receiver (SPIRE) on the upcoming Herschel observatory.
To study statistical properties of these anisotropies, the confusion from
foreground Galactic dust emission needs to be reduced even in the ``cleanest''
regions of the sky.The multi-frequency coverage of SPIRE allows the foreground
dust to be partly separated from the extragalactic background composed of dusty
starforming galaxies as well as faint normal galaxies. The separation improves
for fields with sizes greater than a few hundred square degrees and when
combined with Planck data. We show that an area of about ā¼ 400 degrees2
observed for about 1000 hours with Herschel-SPIRE and complemented by Planck
provides maximal information on the anisotropy power spectrum. We discuss the
scientific studies that can be done with measurements of the unresolved FIRB
anisotropies including a determination of the large scale bias and the
small-scale halo occupation distribution of FIRB sources with fluxes below the
point-source detection level.Comment: 10 pages, 8 figures, replaced to match the extended version, accepted
by Ap