THE STUDY OF ELECTROMAGNETIC TECHNIQUES FOR SPACE NAVIGATION
Abstract
Equipment for the initial phases of the template spectroscopy work has been completely assembled and is being refined. A number of templates have been made using both the sun's spectrum and an iron arc source. Best results to-date have been obtained by matching the iron arc template against the iron lines in the sun's spectrum. Very good discrimination was obtained at the match point with a dc detection system, but changes in light level were a problem. The addition of a wobbulator to impart vibrating motion to the slit of the spectrograph now permits the use of ac detection. Results with the latter system have been very encouraging. A detection sensitivity of 10-15 m/sec has been achieved initially. For the optical heterodyning phase, the radiometer has been placed in operation and checked out satisfactorily. Mounts and motor drives for the optical components have been completed and a lamp holder cavity for the Hg source has been designed. Development of the TWT mixer has been delayed pending an investigation of the use of a cw laser as local oscillator. Analysis shows that the use of a laser would considerably ease the broad band requirement and made possible the use of standard photomultipliers in the mixing stage. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- May 15, 1961
- Accession Number
- AD0257743
Entities
People
- R.g. Franklin
- W.c. Jr. Reisener
Organizations
- Franklin Institute