# Space Weather Effects from Observations by Moscow University Cubesat Constellation
## 2 Multi Satellite Experiment for Real Time Radiation Monitoring in the Near-Earth Space
### Instrument Concept  
Instruments for radiation monitoring should include a spectrometer of protons with energies from 2 up to >160 MeV and electrons with energies of 0.15-10 MeV. Its main element is the assembly as a telescope, including a few semiconductor (silicon) detectors with different thicknesses and scintillator detectors, which are placed coaxially. To measure the pitch-angle distribution and omnidirectional fluxes, several telescopes with differently oriented axes will be used. We also discuss the instrument arrangement, in which the axes of four telescopes lie in the magnetic meridian plane, and the axis of another telescope is normal to this plane. In the case of polar orbit, it means that the axis of four telescopes should lie in the orbital plane.  
The payload should also include a three-component magnetometer.  
The parameters of the spacecraft orbits on which instruments for radiation monitoring will be installed should provide coverage of the entire spatial volume of the observed radiation captured in a magnetic field, i.e., radiation belts. In this case, measurements of omnidirectional fluxes of captured particles should be provided, followed by model interpolation and extrapolation of the measured fluxes to the entire area of radiation belts. Such measurements will allow us to calculate the current distribution of particle fluxes in a large volume of radiation belts, and, as a result, the real-time levels of radiation doses for a wide range of operating orbits will be derived.  
Therefore, in the frame of the mission, several spectrometers of protons and electrons installed on the satellites launched into the special orbits should measure fluxes that allow the prediction of the current energetic charged particle distribution in the large volume of radiation belts up to geostationary orbit. As a sequence, current values of radiation loads can be operatively estimated for a wide range of satellite orbits.  
An important addition to the space monitoring system will be a fully automated ground-based satellite data operational analysis system developed at Moscow State University, designed to evaluate and predict radiation conditions in near-Earth space in real-time.  
For the first stage of multi-satellite project realization, a special instrument for space radiation monitoring was elaborated. It is the so-called DeCoR (Detector of Cosmic Radiation) instrument. It allows the detection of charged particles and gamma quanta in the energy release range of 0.1-2.0 MeV. A detailed description of the DeCoR instrument is given in [28; 29]. It consists of a detector unit and electronic plates mounted inside the CubeSat satellite body. The detector unit is a CsI(Tl)/plastic scintillator phoswich viewed by two PMT. The detector's sensitive area is about 18 cm\({}^{2}\), and the geometric factor is about 50 cm\({}^{2}\)sr.  
The instrument provides separate detection of events in the plastic scintillator and crystal CsI(Tl). In this case, it is possible to realize instrument operation in the so-called event-by-event mode, when information is recorded about the energy released in both scintillators and the time of detection of each particle or quantum that enters the instrument. From this event-by-event recording, a monitor mode is also implemented, in which, for a given time interval, usually 1 s, the number of detected events in each scintillator, as well as the total count, is determined. Thus, time sets of counting rates in a plastic scintillator, i.e., mainly electrons with energies of over 300 keV, and in a CsI(Tl) crystal, i.e., predominantly gamma quanta with energies of over 100 keV, are obtained. Such monitoring data are regularly transmitted to Earth during the experiment. After viewing monitor data, the researcher identifies the time points at which the flow variations of interest actually occurred. For these moments, detailed data are requested for transmission to Earth.