trailing directions (bottom) as a function of geocentric ecliptic longitude along the line of sight. The peak positions of the $\pm\timeform{1.4D}/\timeform{2.1D}$ band are shown in red, the $\pm \timeform{10D}$ band in blue and the circumsolar ring in black. Regions around $45\degree < |\lambda| < 135\degree$ were not used for fitting because of the strong emission near the Galactic plane ($|b| < 15\degree$).[]{data-label="fig:peak"}](band_peaks.eps){width="10cm"}

Table \[tab:gaussian\] summarizes the mean peak surface brightness, mean geocentric ecliptic latitude and band widths obtained from the Gaussian fits. Figure \[fig:peak\] shows the best-fitting results for the peak positions in the Earth-leading and trailing directions. There is an apparent annual variation of the band latitudes with geocentric ecliptic longitude. Sinusoidal variations can be seen in the northern and southern components of each band pair. The annual variation is caused by the Earth’s changing altitude with respect to the midplane of the band pairs.

The sinusoidal variation of the latitude of the dust bands can be expressed using the following parameters: (i) the radius of the band pair centred on the Sun (the heliocentric distance), $R$; (ii) the angle of inclination with respect to the ecliptic plane, $i$; (iii) the longitude of the ascending nodes, $\Omega$; (iv) the 