The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences. Vol. XXXVII. Part Bl. Beijing 2008
and the noise amplitude have been so estimated, and their plots
are shown in Figure 7.
Noise
450 550 650 ,750, 850 950 1050
wavelength (mj
Figure 7: Plot of SNR and noise amplitude (standard deviation)
as computed from 40 interferograms collected observing the
same radiation source.
2.3 Reflectance spectra reconstruction
Standard reflectance tiles together with diffusers doped with
Holmium and Rare Earths have been used to check the
reflectance spectra retrieved from ALISEO interferograms. For
each tile a complete interferogram has been reconstructed, then
the at-sensor radiance have been computed. Reflectance spectra
are calculated taking as reference the radiance spectrum
extracted from a Spectralon tile. Results of these measurements
are plotted in Figure 8.
Retrieved reflectance spectra have been used to verify the
wavelength calibration of the instrument. The obtained results
are in fair agreement with reference data. We suppose that
partial departure of retrieved spectra from refemces is caused
by the still insufficient compensation of the spectral dispersion
ofOPD.
450 550 650 750 850 950
Wavelength (nm)
Wavelngth (nm)
Figure 8: Standard tiles reflectance spectra : reconstructed
spectra from measured interferograms are shown with a bold
line. Labsphere reflectance spectra are plotted with a thin line.
5.CONCLUSIONS
In this paper an imaging interferometer laboratory prototype of
the ALISEO sensor has been presented. The optical layout and
the configuration of the instrument have been analysed, and the
main differences with existing interferometers have been
assessed. A procedure to retrieve the at-sensor radiance has
been presented and discussed. Experimental investigation
carried out at our Institute allowed us to measure the
interferometer spectral resolution and the range of wavelengths
that can be reconstructed. Future activities will be devoted to
the implementation of a procedure for performing atmospheric
corrections of the acquired images on board of an aircraft.
REFERENCES
Barducci A., P. Marcoionni, I. Pippi, M. Poggesi, 2001.
Simulation of the Performance of a Stationary Imaging
Interferometer for High Resolution Monitoring of the Earth, In
Sensors, Systems, and Next-Generation Satellites VII, Proc.
SPIE 4540, pp. 112-121.
Barducci A., I. Pippi, 2001a. Analysis and rejection of
systematic disturbances in hyperspectral remotely sensed
images of the Earth, Applied Optics, 40, pp. 1464 - 1477.
Barducci A., F. Casini, F. Castagnoli, P. Marcoionni, M.
Morandi, I. Pippi, 2002. Performance assessment of a
Stationary Interferometer for High-Resolution Remote Sensing,
in Algotithms and Technologies for Multispectral,
Hyperspectral, and Ultraspectral Imagery Vili, Proc. SPIE
4725, pp. 547-555.
Barducci A., P. Marcoionni, I. Pippi, M. Poggesi, 2003. Effects
of Light Pollution Revealed During a Nocturne Aerial Survey
939