S2LET: A code to perform fast wavelet analysis on the sphere

Understand

We describe S2LET, a fast and robust implementation of the scale-discretised wavelet transform on the sphere.

• Wavelets are constructed through a tiling of the harmonic line and can be used to probe spatially localised, scale-depended features of signals on the sphere.
• The scale-discretised wavelet transform was developed previously and reduces to the needlet transform in the axisymmetric case.
• The reconstruction of a signal from its wavelets coefficients is made exact here through the use of a sampling theorem on the sphere.