English: NASA space telescope SPHEREx is based on a telescope with an effective 20 cm diameter and a 11°x3.5° field of view. The focal plane is split with a dichroic to three short-wavelength and three long-wavelength detector arrays. Each 2K x 2K focal plane array is covered with a linear variable filter, providing narrow-band response with a band center that varies along one axis of the array. SPHEREx obtains spectra through multiple exposures, placing a given source at multiple positions in the field of view, where it is measured at multiple wavelengths by repointing the spacecraft.