How many Spectral Bands does it measure?

As HERA does not employ spectral filters or dispersive elements to direct the different colors of the incoming light to the different pixels of a sensor, it is not possible to determine the exact number of spectral bands. In fact, as the spectrum at each pixel of the image is the Fourier Transformation of the interference signal, the spectrum is a continuous function (or curve). Of course, when plotting the data, one needs to sample the spectrum with a proper number of points…but please note that does not affect the spectral resolution of the measurement and it is not an indication of the number of spectral bands!

The “real” answer to this question is that one needs to refer to the spectral resolution provided by the camera, rather than to the number of spectral bands.