Laszlo Hegymegi

Mingeo

Geomagnetic observatories use classical theodolites equipped with single-axis flux-gate magnetometers known as declination–inclination magnetometers (DIM) to determine absolute values of declination and inclination angles. This instrument and the measurement method are very reliable but need a lot of handwork and experience. The authors developed a...

Geomagnetic observatories use classical theodolites equipped with single axis flux-gate magnetometers known as declination inclination magnetometers (DIM) to determine absolute values of declination and inclination angles. This instrument and the measurement method is very reliable but needs a lot of handwork and experience. The authors developed a...

The temperature characteristics of the 1-second variometer were studied in the real operation environment. For estimations of the instrument thermal drift the two approaches based on the total field difference and base values analysis were used. The total temperature drift was decomposed to the console and the sensor ones using considerable differe...

One of the main challenges on the course of the repeat station surveys is to determine the spatial differences of the geomagnetic elements between the repeat stations and the reference observatory. The difficulty arises from the fact, that the directly obtained differences are affected not only by spatial but also by temporal effects of external or...

Tihany Geophysical Observatory was founded in 1954 to monitor geomagnetic variations. In addition to its original task, however, it has always provided opportunity for other geophysical activities, such as observation and study of paleomagnetic, geothermic, seismologic, and different space phenomena. Geomagnetic data, gathered since 1954 provide an...

For the most part, the D/I fluxgate magnetometer is the only absolute instrument used in observatories and in the field. At present no company produces a nonmagnetic theodolite and there are only a few organizations converting geodetic theodolites to nonmagnetic instruments. A classic theodolite has many parts which have a magnetic moment. These pa...

The magnetic observation at the Tihany Geophysical Observatory was started more than fifty years ago, in 1955. On the occasion of achieving this historical age, the brief history of the geomagnetism in Hungary and the measuring activities at the Tihany Geophysical Observatory is presented. The article gives a retrospective look at the important sta...

Collaboration between ELGI and USGS on a spherical coil design began several years ago. The small size coils are approximately 30 cm in diameter. We use the GSM-90 FD 5D Overhauser magnetometer by GEM Systems. By reducing the duration of a complete set of measurements (five readings: F, D+, D-, I+, I-) to 5 seconds we reached the accuracy level of...

As an observatory recording system for slow magnetic variations has to work 24 hours a day and 365 days a year, it has to be very reliable. There are many ways to increase the reliability of a system but in many cases such an instrument becomes very complicated and needs extensive knowledge to operate it. In this paper we describe a low cost observ...

A description of a new version of an intelligent recording system for magnetic observatories is presented. The system contains magnetic variometers for the H, D and Z components, a proton magnetometer for the total field, a thermometer, and a data acquisition system with a built-in floppy disk recorder. A matrix printer, a local or remote computer...

The main concept of the Digital Intelligent Magnetic Recording System (DIMARS) for the registration of the Earth's magnetic field variations is the following: with the help of an embedded microprocessor it provides the necessary automated functions which provide a maximum available information for the annual report of a magnetic observatory. In thi...

Data for 985 whistlers recorded at Tihany, Hungary (L = 1.9) between December 1970 and May 1975 have been processed for equatorial crossing radius L, equatorial electron density n(eq) and tube electron content N(T). The obtained L values lie in the range L = 1.4-3.2. The median values of n(eq) and N(T) as a function of L fit well to the density pro...

The system consists of three magnetic variometers with electrical output signals for theH, D, andZ components, a proton magnetometer for the total field, a data acquisition system, two cassette recorders, an analogue chart recorder, a calendar clock, and a telex. The analogue and digital input data are sampled at 10 sec intervals, averaged over a m...

Block diagrams are presented of the Tihany digital magnetic recording system and of its power supply system. The design of the system is described in some detail and its physical parameters and output characteristics are briefly discussed.

Tarcsai's (1975) curve fitting method is applied to the analysis of 138 whistlers recorded at Roburent, Italy, in the period December 1972 to March 1973. The corresponding values were obtained for the equatorial electron density and the total number of electrons contained in a tube of unit cross section extending from an altitude of 1000 km to the...