Continuous record of natural electromagnetic Very Low Frequency (VLF) radiation is carried out in IKIR FEB RAS by a multichannel VLF detector. The receiving site is located far from industrial noises. The measurement station provides the following: data acquisition; graphic representation of data; storage of data in the required form for further analysis. The measurement station consists of a receiving part and a data acquisition module. The receiving part includes antennas, amplifiers and filters. The data acquisition module includes a repeater unit, an analog-digital converter (ADC), a digital detector, and a digital filter.  Two frame antennas oriented according to the cardinal points (north-south and east-west) are used in the complex. They receive the magnetic component of natural electromagnetic field in VLF range. The electric antenna is a 6-meter pin installed on a 3-meter foundation. The magnetic antenna consists of similar vertically arranged frames with the dimensions of 7.5х15 m. Their planes are oriented in the directions of north-south and east-west. 89 coils of a copper wire are wound around each frame. Pre-amplifiers are mounted at the bottom parts of the antennas.

The VarSITI have decided to support IKIR FEB RAS database construction entitled "Creation of a database for atmospheric and whistler events detected in the Russian Far East". The goal of IKIR FEB RAS project is the creation of a database for atmospheric and whistler events detected in the Russian Far East. The database was obtained by the recognition of atmospherics in WAV files, which were obtained by recording the VLF signals with electric and/or magnetic antennas.

1. The database of registered atmospherics at Karymshina Geophysical Observatory of IKIR FEB RAS (N52.49 °, E158.07 °) in Kamchatka is available at the following address: http://files.ikir.ru:8080/users/mochalov/varsiti/history/karymshino/algorithm1/ . The database stores the number of recorded atmospherics per second.

The database is divided into folders by year. The database stores files both in text format (the extension of file is lsf.txt) and in Java-serialized (the extension of file is lsf). Each Java-serialized final file with the .lsf extension contains entries for a specific month. Each record stores the time T (UTC), the number of numSeconds, and the byte array with the size of numSeconds bytes, where each byte of Bi contains the number of counted atmospherics in i second since time T. Each record has the following structure:
- year (2 bytes),
- month (1 byte),
- day of the month (1 byte),
- hour (1 byte),
- minute (1 byte),
- second (1 byte),
- the number of milliseconds (4 bytes),
- field numSeconds (2 bytes),
- an array of bytes (numSeconds bytes).

An example of Java code for reading a file with the .lsf extension is available by this this link .

2.  An automatically updated database of registered atmospherics on mini-computer software and hardware complexes for distributed monitoring of low-frequency electromagnetic radiation is available at the following address: http://files.ikir.ru:8080/users/mochalov/varsiti/minipc/ . The minimum time delay of data publication on this site is 24 hours.
Currently mini-computer software and hardware complexes are located:
- in Karymshina Geophysical Observatory of IKIR FEB RAS (N52.49 °, E158.07 °) in Kamchatka,
- in "Oybenkel" Geophysical Observatory of (N61.93 °, E129.36 °) of the Yu.G. Shafer Institute of Cosmophysical Research and Aeronomy, the Sakha (Yakutia) Republic,
- in Vladivostok (N43.20 °, E131.92 °) in the V. I. Il'ichev Pacific Oceanological Institute. Note: the monitoring complex of low-frequency electromagnetic radiation is located in the city of Vladivostok (the quality of the analyzed signal is currently low). 

The database is divided into folders according to the location of the monitoring station. The database stores files both in text format (the extension of file is lsf2.txt) and in Java-serialized (the extension of file is lsf2). Each Java-serialized final file with the .lsf2 extension contains entries for a particular day. Each record stores the time T (UTC), the numValues ​​number and the array of pairs (msTime, amp). The msTime field is intended for storing the time of the atmospheric registration. The msTime field stores the number of microseconds that have elapsed either from the time T (for the first atmospheric of the array of pairs (msTime, amp)) or from the previous atmospheric (for the second and the following atmospherics of the array of pairs (msTime, amp)). The amp field stores the integer amplitude of the atmospheric. Each entry has the following structure:
- year (2 bytes),
- month (1 byte),
- day of the month (1 byte),
- hour (1 byte),
- minute (1 byte),
- second (1 byte),
- the number of milliseconds (4 bytes),
- field numValues ​​(4 bytes),
- an array of pairs (msTime, amp) ((4 1) * numValues ​​bytes). The msTime field is 4 bytes and amp is 1 byte.
 
An example of Java code for reading a file with the .lsf2 extension is available by this link .   

3. An automatically updated database of registered whistlers on mini-computer software and hardware complexes for distributed monitoring of low-frequency electromagnetic radiation is available at the following address:  http://files.ikir.ru:8080/users/mochalov/varsiti/whistlers/minipc/ . The minimum time delay of data publication on this site is 24 hours. At the moment, qualitative registration of whistlers is performed in Karymshina Geophysical Observatory of IKIR FEB RAS (N52.49 °, E158.07 °) in Kamchatka and in "Oybenkel" Geophysical Observatory of (N61.93 °, E129.36 °) of the Yu.G. Shafer Institute of Cosmophysical Research and Aeronomy, the Sakha (Yakutia) Republic.
The database is divided into folders according to the location of the monitoring station and the used algorithm for whistlers detection.The database stores files both in text format (the extension of file is wsf1.txt) and in Java-serialized (the extension of file is wsf1). Each Java-serialized final file with the .wsf1 extension contains entries for a particular day. Each record stores the start time of the analyzed interval T (UTC) (the storage format of T is the same to clause 2), the length in milliseconds of the analyzed interval millisDiffer (type int), the number of detected whistlers numWhistlers (type int) and array M, consisting of numWhistlers elements. Each element of array M stores the time (int type) of whistler registration in milliseconds that have elapsed from the time T.

An example of Java code for reading a file with the .wsf1 extension is available by this link .

4. The history database of registered whistlers with magnetic East-West and vertical electric antenna is available at the following address. Whistlers were registered in Karymshina Geophysical Observatory of IKIR FEB RAS (N52.49 °, E158.07 °) in Kamchatka. The database also stores files both in text format (the extension of file is wsf1.txt) and in Java-serialized (the extension of file is wsf1).

Published papers with SCOSTEP/VarSITI grant support:

1. Mochalov V.A., Mochalova A.V.. Application of «Sensor signal analysis network» complex for distributed, time synchronized analysis of electromagnetic radiation // VIII International Conference “ Solar-Terrestrial Relations and Physics of Earthquake Precursors”, 6 pages, DOI: https://doi.org/10.1051/e3sconf/20172002010 , 2017.
2. Mochalov V.A., Permyakov M. S., Cherneva N.V., Mochalova A.V. Functional scheme of the construction process of a multi-site system for lightning activity monitoring of tropical cyclones // Proc. SPIE, 23nd International Symposium on Atmospheric and Ocean Optics: Atmospheric Physics, 4 pages, 2017.
3. Mochalov V.A., Firstov P.P., Cherneva N.V., Sannikov D.V., Akbashev R.R., Uvarov V.N., Shevtsov B.M., Druzhin G.I., Mochalova A.V. Development of a monitoring network for lightning stokes accompanying the eruptions of the Northern Group of Volcanoes on Kamchatka peninsula // Proc. SPIE, 23nd International Symposium on Atmospheric and Ocean Optics: Atmospheric Physics, 4 pages, 2017.

The developed program in the process of working on SCOSTEP/VarSITI grant tasks:

1. V.A. Mochalov. Software platform for streaming analysis of time synchronized signals // Certificate of registration of computer software, № 2017619795 (2017).

Email address for contacts: vmochalov@ikir.ru ( Ph.D. Vladimir Mochalov )

Acknowledgments:

The work was supported by the  SCOSTEP/VarSITI grant “Creation of a database for atmospheric and whistler events detected in the Russian Far East”.