Film readings for the FMI-1977 all-sky camera
The so called film-readings (or all-sky camera summary tables) are
manually created by viewing the photographic records which are
made on 16mm colour film at a typical rate of one frame per
minute. Data is recorded at higher frame rates (up to six frames
per minute) during selected periods. The start and stop time of
camera operation and an average over the hour of auroral intensity
and weather conditions is included in the tables. Most of the data
has been digitalized by Peter Amberntsson (many thanks to him for
doing this tedious work).
The film readings (i.e. the ASC summary tables) are ONLY intended
to give information when data is available. They should be used
with extreme care in statistical studies. This is the case since
many people has been reading the films over the years, using
slightly different criterias for the legends. Also, more effort
has been spent during interesting periods (campaigns, etc.), which
causes a significant bias on the data set. Finally the difference
between some legends are not well defined causing further
degradation of the statistical quality of the film readings.
- c Cloudy
- a Aurora.
- r Some red aurora.
- A Strong aurora.
- R Strong red aurora.
- / No aurora, clear weather.
- + Camera fault
- - Camera off (camera not running due to daylight, snow or rain)
- ac Aurora and clouds.
- rc Red aurora and clouds.
- Ac Strong Aurora and clouds.
- Rc Strong red aurora and clouds.
For further information please contactUrban Brändström
Last modified: Tue Feb 24 10:15:01 UTC 2004