Some problems with old magnetic data processing

Abstract

Continues magnetic measurements at the IKIR FEB RAS obser-vatories Magadan (MGD), Paratunka (PET), Yuzhno-Sakhalinsk (YSS), Cape Schmidt (CPS) and Khabarovsk (KHB) and CSIR-NGRI observatories Hyder-abad (HYB) and Choutuppal (CPL) have been started almost since their formation. A significant part of the results obtained is presented in the WDC and INTERMAGNET databases. However, a large amount of raw data remains un-processed and unavailable for using by scientific community. In the past few years, institutes has been making efforts to process and reprocess old magnetic data. Digital images of analog magnetograms of the Observatory Paratunka since 1967 were obtained and the possibility of their use for calculation hourly and minute values of magnetic field elements was evaluated. Old digital data that was available during the conversion from analog to digital magnetometers is processed. The main problem of processing or re-processing archived data is the lack of information (metadata) about the measurement conditions. First of all, these are the results of absolute observations, which are necessary to obtain the values of the elements of the total field vector. In this paper, some technologies are proposed that allow to use the data obtained during processing of analog magnetograms to adjust the digital magnetometers records. A signif-icant problem is the lack or inaccuracy of information about the temperature conditions in the variation pavilion, about magnetometers or support equipment maintenance or about works in and near the pavilions. As we accumulate the experience during the processing of old magnetic data, a “catalog” of noise and its typical images is formed. This makes it more reliable and efficient to identify and remove this noise from records.