  Time-resolved photometry of asteroids can be used for shape and spin
reconstruction. If the number of measurements per asteroid is not sufficient to
create a model, the whole data set can be used to reconstruct the distribution
of shape elongations and pole latitudes in the population. This is done by
reconstructing amplitudes of lightcurves that are estimated from dispersion of
points observed at (assumed) constant aspect angle. Here, we formulate
orbit-averaged approach where the observable is the orbit-averaged dispersion
of brightness.
