A Real Time Fourier Transform Synthesizer

Item

Title
A Real Time Fourier Transform Synthesizer
Date
1966
Index Abstract
Coming Soon
Photo Quality
Not Needed
Report Number
AFCRL 67-0049
Creator
Hoffman, J. E., Jr.
Corporate Author
Utah State University Electro-Dynamics Labs
Extent
125
NTRL Accession Number
AD653200
Identifier
AD0653200
Distribution Classification
1
DTIC Record Exists
Yes
Distribution Change Authority Correspondence
None
Abstract
A study of the relationship between the interferogram F(x) obtained in Fourier spectroscopy and the corresponding spectral distribution E is made. It is found that the spectral distribution is the Fourier cosine transform of the interferogram. Various computational techniques for performing the required transformation are studied, and a real time Fourier transform synthesizer is described. It has been designed to be compatible with a lamellar grating Michelson interferometer, but could be used just as well with a well-compensated Michelson interferometer. The system used to obtain the point of zero path difference is described in detail. A novel approach is used to obtain the cosine functions required in the synthesis of the cosine transform. All the computations except the summation are done in analog form, while the summation is done digitally. The result of the computation, the spectral distribution, is available as soon as the interferogram is obtained. Errors in the technique are discussed and methods of compensating for them are enumerated.
Report Availability
Full text available by request
Date Issued
1966-11
Provenance
IIT
Type
report