Special space-physics lab exercises

The purpose of the space-physics lab exercises is to introduce the students to the methods of the measurements, to the modern conception of near-Earth space structure and the physical processes and phenomena occured in it. It's also intended to the teaching of the basic methods of experimental data processing and analyzing.

The lab exercises are based on the experimental data, obtained by the supersmall satellites "Universitetskiy" and "Kompas-2".

MSU-site also provide information about the geographical and geomagnetic coordinates of the observation point (latitude and longitude), McIlvine's coordinates (L, B), Universal time (UT) and indices of geomagnetic activity K_p Х D_st.

At present the reasearches and the teachers of the University and of other institutes participating in the project continue development of the the special space-physics lab exercises, and they are interested in your ideas concerning the future exercises.

The exercises

1. Observations of the radiation belts at the altitude of 400-1000 km

The purpose of the exercise is to teach the students the methods of the analysis of the temporal and spatial variations of charged particles fluxes of the Earth's radiation belts on the basis of the experimental data obtained from the low-altitude satellites. The exercise is based on the experimental data of the satellites "Universitetskiy" (H ~ 1000 km) and "Coronas-I" (H ~ 400 km) with approximately equal inclination (about 80°). In order to perform the exercise it is necessary to have practical skills in operation with the space-physics experimental data and any data plotting program. The exercise can be recommended for the students of the Physics departments of the Universities and other Institutes (within the framework of the Nuclear Lab Exercises).

2. Trapped particles fluxes in the region of the South-Atlantic Anormaly

The purpose of the exercise is to teach the students the effects of the influence of the geomagnetic field on the movement of the radiation belts' particles and on their distribution at low altitudes. The exercise in intended for the students of the Physics departments of the Universities and other Institutes. It can be also used for elective courses of the high-school pupils.

3. Solar cosmic rays

The purpose of the exercise is to introduce the students with the methods of analysis of the flux and spectrum dynamics of the solar cosmic rays (SCR) on the basis of satellites experimental data. Solar cosmic rays analysis is important not only for the studies of the fundamental problem of the particles' acceleration on the Sun and in the heliosphere, but also for applied problems, because SCR are one of the basic "space weather" factors. The description of the exercise includes brief information about the SCR variations, flare mechanisms of the charged particles' acceleration, their spreading in space and SCR's influence on the near-Earth space. The exercise is based on the experimental data of the satellites "Universitetskiy", GOES and ACE. In order to perform the exercise it is necessary to have practical skills in operation with the space-physics experimental databases and any data plotting program. The exercise can be recommended for the students of the Physics departments of the Universities and other Institutes (within the framework of the Nuclear Lab Exercises).

4. The solar wind in the heliosphere

The purpose of the exercise is to introduce the students to the structure of the interplanetary magnetic field, heliosphere, spreading of the solar wind and flare emissions of the solar matter. It also includes the method of restoration of the location of the solar flare caused the geomagnetic storm. The exercise is intended for the students specialized in the fields of physics, space, astronomy, natural sciences. The student does not need to provide any special knowledge or skill for the performance of this exercise.

5. Ultraviolet radiation of the night atmosphere of the Earth

The purpose of the exercise is to introduce the students to the methods of the ultraviolet (UV) radiation measurements by means of the equipment of the "Universitetskiy" satellite. The subjects of the studies includes the atmospheric fluorescence, light's dispersion in the atmosphere, UV back flux from the atmosphere, UV auroras. The description of the exercise includes brief information about these phenomena. The exercise is based on the experimental data of the "Universitetskiy" satellite. In order to perform the exercise it is necessary to have minimum skills in the field of operation with Internet databases. It's also useful to find the basic information in the multimedia lectures "Life of the Earth in the Solar Atmosphere". The exercise can be used within the framework of the General Physics Course ("Optics" and "Atomic Physics"), and in special courses on plasma physics, astrophysics and geophysics for the students of the Physics departments of the Universities and other Institutes. It can be also used for elective courses for the high-school pupils.

6. Calculation of the second zonal harmonics of the Earth's gravitational field

The purpose of the exercise is to give the students an opportunity of practical use of information about the Kepler parameters of the satellite's orbit received from the ground-based observatory services (NORAD in particular) in order to estimate parameters of the Earth's non-sphericity. This task is important to understand the methods of on-board measurements binding to the real geographical and spatial coordinates. The amplitude of the second zonal spherical harmonics is chosen as a measurable parameter due to its maximum impact into the declination of the Earth's field from the spherical shape. It is supposed to use the elements of the students' self-sufficient programming for processing of the real satellite's location database during the performance of the exercise. The exercise is recommended for the students of the Physics departments of the Universities and other Institutes (within the framework of the general Mechanics Lab Exercises).

7. Variations of the relative atmosphere's density at the orbit of the satellite

The purpose of the exercise is to check a simple model of the action of the atmospheric molecular resistance force on the satellites at comparably low approximately circular orbits.

Performing the exercise the students learn the physical effects of the influence of the molecular friction in the Earth's atmosphere on the changes of the Kepler parameters of the satellite's orbit. The exercise also allows to learn about the influence of solar activity on the characteristics of the upper atmosphere of the Earth comparing changes of the relative atmosphere's density at the altitude of the satellite's orbit with the solar activity characteristics.

Specific coefficient of the resistance of the atmosphere to the satellite's movement (coefficient of the resistance related to the satellite's weight) is chosen as a measurable parameter in the exercise. Focal parameter of the orbit calculated by mean movement (a number of turns per day) is used as a parameter which allows to estimate the changes of the specific coefficient. The specific coefficient of the satellite's resistance is calculated by the velocity of the focal parameter's changes, and it allows to estimate the relative changes of the atmosphere's density at the satellite's orbit. If we know the cross-section and the weight of the satellite we can calculate the absolute value of the atmosphere's density at the satellite's orbit.

At the last stage of the exercise it is supposed to perform a comparative analysis of the solar activity parameters and the changes of the absolute and relative density of the atmosphere at the altitude of the orbit. It is supposed to use the elements of the students' self-sufficient programming for processing of the real satellite's location database during the performance of the exercise.

The exercise is recommended for the students of the Physics departments of the Universities and other Institutes.

8. Calculation of the projection of the Kepler satellite's orbit to the geographical map of the Earth

The purpose of the exercise is to give to the students the practical skills of modelling of the satellite's movement along the orbit with binding of its location to the real geographical coordinates.

The exercise is realised in any programming environment (Pascal, C, C++) or in the integrated math packages which provide an opportunity to visualise the calculated elements of the orbit.

It is supposed to realize adaptation of the real navigation data of the Kepler parameters of the orbit in order to calculate the current location of the satellite at the orbit without taking into consideration disturbing factors. In the advanced variant of the exercise the author offers to use the second zonal harmonics and the friction in the atmosphere.

This exercise includes the principles of the modelling of the satellite's movement along the orbit. Its importance is caused by the fact that one of the problems of the satellite's data processing is in their binding to the spatial coordinates because it is impossible to get information about the satellite's location at the orbit and about the orbit's parameters from navigation services ceaslessly. Such information is received several times per day or even once per several days while satallite's data has time resolution from the fractions of seconds up to several hours. Therefore it is necessary to calculate the satellite's location for every data point using the program for the satellite's movement modelling.

It is supposed to write a small program for calculation of the geographical coordinates of the projection of the satellite's location to the celestial sphere basing on the Kepler parameters of the satellite's orbit.

© Skobeltsyn Institute of Nuclear Physics.