Umbra
1931
Article/Chapter (Book)
German
A new empirical model of a sunspot umbra
NTRS | 1971
|On Satellite Umbra/Penumbra Entry and Exit Positions
Online Contents | 1998
|Umbra and penumbra eclipse factors for satellite orbits
AIAA | 1964
|On Satellite Umbra/Penumbra Entry and Exit Positions
Springer Verlag | 1998
|TECHNICAL NOTE - On Satellite Umbra-Penumbra Entry and Exit Positions
Online Contents | 1998
|