East-Siberian Center for the Earth's Ionosphere Research (SDC ESCEIR)

Composition
Objectives
Capabilities and samples
Request for work
Back to main page

Short-wave ionosphere diagnostics subdivision
Mathematical modelling and information support subdivision

Databases

At the heart of the automatic informational system (AIS) is the database (DB). DB allows us to provide a uniform exchange between various AIS modules. To write and store data in DB we have developed two standard formats: the N1 format for initial experimental data, and the N2 format for data processing and computation results. The continuous chirp-signal ionospheric sounding system provides real-time information on ionosphere conditions and propagations modes for vertical, oblique and back-scattering sounding (VS, OS and BSS ionograms with amplitude relief). Standard format N1 is unified and allows us to store ionograms for different types of sounding systems. It consists of two zones: the service information zone, and the ionogram zone. To compress the information we use special coding. Standard format N2 consists of the passport and the data zone. The passport contains the necessary service information on the radio run, the data zone contains signal characteristics and parameters. On the basis of Clarion we have developed:

• DB for writing and storing vertical, oblique and back-scattering ionospheric sounding ionograms;
• DB for storing ionogram processing results;
• DB for geographical points and stations;
• DB for solar activity indices;
• DB for technical parameteres;
• DB for prediction and real-time diagnostics.

Experimental databases servicing.

Ionogram database

Structurally, the experimental ionogram database consists of the ionogram catalogue and ionograms themselves. The ionogram catalogue is divided into the data file and the key file. The data file contains ionogram service information: sounding type, signature of the existence of ionogram in the DB, ionogram processing signature, station code, date and time. The key file contains data file record numbers sorted by date and time. By using a usual binary search, we can quickly obtain the record number for a given date and time, and thus to restore ionogram service information from data file. These data are stored in format N1 and placed on a hard drive in such a manner that the path to the ionogram gives the sounding type, date, time, and station code. Way coding structure is presented on the figure. All ionograms are stoted on the hard drive in packed form under one name source. If we have the ionogram catalogue, then we can quickly obtain information on ionogram existence and build the path to this ionogram. The ionogram structure as a single hard drive file allows the operator to carry out a database examination without any additional efforts.

Processing results database

To store processing results we have developed the processing results database. This database is analogous to the experimental data database. The processing results DB consists of the data file, the key file and a so-called memo-file. This three-file set is intended for every kind of sounding.

The data file contains service information, which is needed to search the required information (date, time, ionogram type, and so on). The key file contains key elements for data file records and can be used for a quick search. The memo-file contains variable length ionogram processing results stored in the N2 format. A minimum record size for the memo-field is 256 bytes, and a maximum size is 65000 bytes.

Station codes database

To store sounding station parameters we have developed the station codes DB in which each station has its own code. The station codes database consists of the data file and two key files. The data file contains station information (transmitting and receiving locations names and coordinates). The key files contain key elements for data file records (key to coordinates and station code) and can be used for a quick search.

Geographical locations database

The geographical locations database contains all necessary information about geographical locations. The user can edit the locations database. The locations database consists of the data file and two key files. The data file contains the location name and its coordinates. The search in key files is carried out by the location name and coordinates.

Solar activity indices database

The solar activity indices database contains monthly mean indices. We are storing the F10.7 index and the Wolf number. Storing two indices is foreseen for various user programs interacting with the database. The solar activivity indices database can be refreshed. There is an opportunity to view a sigle day solar activity index. This database consists of the data file and the key file. The data file contains monthly indices. The search in the key file is carried out by date.

Antenna base

The antenna DB consists of two interrelated databases. These are the theoretical (descriptive) antenna DB and the real antenna DB. The theoretical antenna DB contains the following information: antenna code, antenna name, parameters names, parameter measurement units, and the high and low boundary for the parameter (the theoretical antenna DB can store up to 15 parameters). The real antenna DB contains real antenna parameters, the antenna code, and the antenna name. These two DB interact by means of the antenna code, that is, if we know the antenna code from the real antenna DB, then we can determine the parameters names and their measurements units by accessing the theoretical DB. The theoretical antenna DB consists of the data file and the key file. The data file contains the following information: antenna type, antenna name, antenna parameters names, measurement units, and ranges of parameters. Each antenna has its unique code. The key file can used for quick data search.

The real antenna DB consists of the data file and two key files. The data file contains information on the antenna code, antenna type, and parameters values. The first key file contains key elements to the antenna code, and the second contains the antenna name.

Result database

To store prediction results and for in-line diagnostics we have developed the results DB. This DB is analogous to the results processing DB and consists of the data file, key file and memo-file. There is a three-file set for every type of sounding. The data file contains the following service information: sounding type, transmitting and receiving locations coordinates, radiorun length, transmitting angle, date, time , processing method number, ionospheric model number, electron density profile number, transmitting signal type number, transmitting antenna type number, solar activity index, three months average solar activity index, transmitter power, transmitter antenna parameters values, and receiving antenna parameters values. Also, we have file lists for descriptors which can be corrected.

The key file contains data file record numbers sorted by date and time and can be used for a quick search. The memo-file contains prediction results and on-line diagnostics data in the N2 format.

The memo-file allows us to store variable length information. A minimum record size for the memo-field is 256 bytes, and a maximum sizeis -- 65000 bytes. For user's convenience, we have separate memo-files for prediction results and for on-line diagnostics.

Experimental data database servicing

The Figure we presents a functional diagram of the program package for storing data in the database and experimental ionogram examination and processing. The integral envelope - program "Manager", can perform the following set of operations:

• ionogram catalogue examination by year, month, hour, minute, seconds, and by sounding type;
• storing ionograms to the database;
• removing ionogram from the catalogue;
• ionogram checking in the catalogue;
• displaying ionogram on the monitor;
• ionogram processing in the automatic and semi-automatis modes;
• storing ionogram processing results to the database.

The regime "ionogram catalogue display" mode gives an opportunity to display all ionograms in the DB. This mode is accomplished in the calendar form". By moving along the calendar using the arrows, we can examine the DB of date and sounding types in going from level to level. If the desired ionogram is chosen, then the operator can display it, mark to remove or process in the automatic or semi-automatic mode. Processing results are stored to the processing results DB. If in the usual ionogram display there is a sign of processing, then the operator can view processing results through ionogram superposition.