Аскаплоты советских станций за 1975 год : (оперативно-информационный материал) / Акад. наук СССР, Кол. фил. им. С. М. Кирова, Поляр. геофиз. ин-т. – Апатиты : Кольский филиал АН СССР, 1988.

8 DESCRIPTION OF ASCAPLOTS. Introduction. The present issue contains observational data obtained by all-sky cameras at eleven Soviet stations during 1975, eight stations are located in the Arctics and three in Antarctica. The stations are enumerated in Table 1. The third colomn contains conventional designations of stations according to the agreement adopted during 1GY /1,2,/. For the stations which did not operate during IGY (the numbers after 115) the designations are compiled in the same way (the ordinal numbers and three Latin letters denoting the name of the station). Corrected geomagnetic coordinates calculated from Gustafsson's data /3/ and geographical coordinated are given in the 4-th and 5-th colomns, respectively. The б-th colomn presents local geomagnetic midnight in UT for each station. The last but one colomn contains the institutions running the observations whereas the last one gives the name of the observer-in-chief. According to Moscow IAGA Assembly resolution of 1958 it is desirable when using ascafilms to refer to or to give the name of the person who obtained the ascafilms. Auroral data are presented by ascaplots aa adopted at Moscow IAGA Assembly in 1958. The method of ascaplotting was offered by W.Stoffregen who edited two volumes of ascaplot data from the global network of stations for 1957-1958 and 1958-1959 /1,2/. Lately occasional issues of ascaplots from Alaskian and Canadian network of stations have been published. Ascaplots of Loparekaya station for 1970-1979 are published in the issue "Auroral phenomena". Auroral observational data from Soviet Arctic and Antarctic stations for 1972- 1974 and 1977-1979 are published in /5-6/. Ascaplots help to obtain operative information on the time and place of aurorae observations and of some auroral parameters. Moreover, identical presentation of the data from different stations with a sufficiently large amount of observations allows to carry out scientific research. For example, the first model of the auroral oval suggested by Feldstein /7/ was obtained due to processing of ascaplots from the global network of stations and was published in /1,2/. Instruments and the program of observations. Observations at Soviet stations were carried out by all-sky cameras designed by Prof. A.I.Lebedinsky /8/. The optical system of the instrument consists of two spherical mirrors and a camera operating automatically from a command apparatus controlled by a contact chronometer. The program of observations envisaged synchronous per minute filming with 20 s exposure centered to the zero second during the whole dark time when atmo spheric precipitation is absent. For auroras occuring in the zenith or in case of increase of auroral brightness up to 2 balls and more an additional 5 s exposure was turned on. Filming was started and finished at the solar zenith angle 99°. In this case the stars of the second stellar magnitude are seen at the sky background. A patrol filming with 20 s exposure was taken every 5 minutes during complete or partial cloudiness and auroral absence. The observations on the whole network of stations were run in Universal Time to secure synchronous filming. Filming was carried out on the Soviet 35-mm KN-4 film. The sensitivity range of dynamic brightness of Soviet ascafilms equals to the order of two. Each film has a standard sensitive wedge produced by a FSR-4 sensitometer. All the negatives of the stations enumerated in Table 1 are kept in the Auroral Subcenter of the World Data Center WDC B2 in Apatity (Auroral Subcenter, Polar