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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: U.S. Standard Atmosphere Supplements
From: Marcel Tschudin
Date: 2005 Aug 27, 18:30 +0300
From: Marcel Tschudin
Date: 2005 Aug 27, 18:30 +0300
Frank, you wrote > I think you'll find that the US Standard Atmosphere is mostly relevant to > very high altitude issues like supersonic/hypersonic flight and > spacecraft > re-entries (and in fact if you search for this title on google image > search > you'll discover photos of its cover art which shows a satellite orbiting > the > Earth). For refraction near the horizon, you need details on the lower > troposphere > which is really a weather issue. And as such you can find data on it from > weather resources. It is correct that it is difficult to read out of the graph the values for the lower part of the atmosphere. That is one reason for looking for tabulated values; in addition, I also did hope that the tabulated values would cover this part more detailed than the graph. The reason why I am aiming for theses temperature profiles is because they show average values for different geographical latitudes and for different seasons (summer and winter). In addition they are still more detailed in the lower atmosphere than the "general" standard lapse rate of -6.5degK/km. If averaged balloon data would be available in a simmilar way (different latitudes and seasons), the US Standard Atmosphere data could be complemented with them. My thoughts are going in the following direction: The program I am working on requires the calculation of refraction for any location on the globe and for heights up to 11000m, i.e. for altitudes from -3deg to 90deg. A possible way of doing this could be by calculating refraction tables (e.g. with the data from the U.S. Standard Atmosphere) for different latitudes and different seasons and interpolate the resulting refraction value for a certain altitude from those tables, depending the location's latitude and the day within the seasons. Marcel