Patent ID: 9297699
Filing Date: 2016-03-29
CPC Classification: G01J

Claim Text:
1. A method of calibrating a spectrometer orbiting the Earth, the method comprising the steps of: imaging the Earth, using the spectrometer, for long-term observations of the Earth's albedo; imaging the Moon by raster scanning the Moon during multiple periods using a scan mirror of the spectrometer, wherein each period provides a short-term observation of the Moon; sampling energy returned from the Moon during each period from raster scan data obtained during each period of the multiple periods; integrating the sampled energy over the multiple periods; autocorrelating the sampled energy; and when the results of the autocorrelation of the sampled energy indicate that the integrated sampled energy has changed over the multiple periods by a delta amount, calibrating the spectrometer using the delta amount determined based on the autocorrelation.