Weather And Seeing
Seeing for Ockham
The seeing value tries to quantify the best current resolution possible in arc seconds. These values reflect the amount of
turbulence in the atmosphere between various layers of air. These can be divided into three sections each one making their own contribution.
1. Low altitude 0 to 100 m
Mainly local building structures radiating heat at different rates causing local convection currents.
2. Mid altitude 100 m to 2 Km
Mainly large cities, densely populated areas, mountain ranges or other large uneven surface features can create turbulent air flows.
3. High altitude 6 Km to 12 Km
This altitude is effected by the fast moving Jet stream air flows. Its position will vary on a seasonal basis. Unfortunately the effects
cannot be avoided but forecasts are available that predict its position and magnitude.
The seeing reflects the clarity and steadiness of the atmosphere layers. A good value will help provide a clear in focus image. However it is possible to have good seeing conditions and thick cloud cover so the two values must be used together to reflect the real world conditions.
The seeing value tries to quantify the best current resolution possible in arc seconds. These values reflect the amount of
turbulence in the atmosphere between various layers of air. These can be divided into three sections each one making their own contribution.
1. Low altitude 0 to 100 m
Mainly local building structures radiating heat at different rates causing local convection currents.
2. Mid altitude 100 m to 2 Km
Mainly large cities, densely populated areas, mountain ranges or other large uneven surface features can create turbulent air flows.
3. High altitude 6 Km to 12 Km
This altitude is effected by the fast moving Jet stream air flows. Its position will vary on a seasonal basis. Unfortunately the effects
cannot be avoided but forecasts are available that predict its position and magnitude.
The seeing reflects the clarity and steadiness of the atmosphere layers. A good value will help provide a clear in focus image. However it is possible to have good seeing conditions and thick cloud cover so the two values must be used together to reflect the real world conditions.
