RESUMO
Offner imaging spectrometer is a kind of pushbroom imaging system. Hyperspectral images acquired by Offner imaging spectrometers require relative motion of sensor and scene that is translation or rotation. Via rotating scan with a reflector at the front of sensor's len, large objects can be entirely captured. But for the changes in object distances, geometric distortion occurs. A formula of space projection from an object point to an image point by one capture was derived. According to the projection relation and slit's motion curve, the object points' coordinates on a reference plan were obtained with rotation angle for a variable. A rotating scan device using a reflector was designed and installed on an Offner imaging spectrometer. Clear images were achieved from the processing of correction algorithm.
RESUMO
In the present paper, the authors propose a method to measure the spatial and spectral distribution of hollow cathode lamp by imaging spectrometer. A push-broom convex grating imaging spectrometer based on Offner system is presented, with wavelength range 400-1 000 nm, field angle 22 degrees and spectral resolution 2-3 nm. The spatial distribution of Hg hollow cathode lamp was measured for the first time; this gives the spatial intensity distribution for different wavelengths and spectral distribution at different positions, with high spatial and spectral resolution. Also the hyperspectral data under different working current condition was obtained in order to analyze the differences of the distribution. It will be a powerful tool for the spatial and spectral properties measurement of hollow cathode lamps and other kinds of light sources.
