The distribution of interplanetary dust between 0.96 and 1.04 au as inferred from impacts on the STEREO spacecraft observed by the heliospheric imagers - Davis, C; Davies, J; St Cyr, O; Campbell-Brown, M; Skelt, A; Kaiser, M; Meyer-Vernet, N; Crothers, S; Lintott, C; Smith, A; Bamford, S; Baeten, E (Monthly Notices of the Royal Astronomical Society, 2012)