Infrared Radiometric Observations of the Solar Corona During the Total Solar Eclipse of 20 July 1963

Radiometric measurements of the solar corona have been made in the spectral region 1.15–5.1 μ during the total solar eclipse of 20 July 1963. A 78.7-cm diam, f/2 radiometer equipped with a thermistor bolometer detector was employed. Four wide band interference filters were used for spectral isolation, namely, 1.15–2.60 μ, 2.9–4.2 μ, 4.5–5.1 μ, and 7.6–13.4 μ. Coronal spectral intensities were measured as a function of radial position. The radial dependence of these intensities was calculated and compared with the van de Hulst model of the visible corona. Radiometric measurements were made during and after totality.