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This paper addresses the further development of the ground based TEMPerature RAdiaometer TEMPERA, which was used successfully for temperature retrievals up to an altitude of 50 km in the period from 2013–2017 [1], [2]. The latest innovation is a new front-end, which allows a fully polarimetric analysis of the measured microwave radiation, in combination with improved inversion methods. In the new forward model the Zeeman effect (see Section 2) and the circular polarization of the microwave radiation is taken into account. Based on this new technology, it should be possible to retrieve atmospheric temperature and Earth's magnetic field up to the lower mesosphere.

The connection between earth and space weather has numerous impacts on spacecraft, radio communications, and GPS signals. Thus, predicted & modeling this region is essential, yet models (both empirical and first principles) do a poor job of characterizing the variability of this region. One of the main objectives of the NASA ICON mission is to measure the variability of the ionosphere and thermosphere at low-mid latitudes. The MIGHTI instrument on ICON is a Doppler Interferometer that measures the horizontal wind speed and direction with 2 discrete MIGHTI units, separated by 90°, mounted on the ICON Payload Interface Plate. This work focuses on building a simulation of wind interferometer data, similar to MIGHTI, using a first-principles model as the input dataset, which will be used for early validation and comparison to the MIGHTI data. Using a ray-tracing approach, parameters like O, O 2 , O + , O 2+ , T, wind, will be read for every point along every ray from the model and brightness and Line of Sight (LOS) wind will be calculated as functions of altitude and time. These data will be compared to the MIGHTI observations to both to establish the limitation of such models, and to validate the ICON data. ICON will help determine the physics of our space environment and pave the way for mitigating its effects on our technology, communications systems, and society. However, ICON is yet to launch and due to the unavailability of MIGHTI data, we have selected another instrument called WINDII (Wind Imaging Interferometer) from a different mission UARS (Upper Atmosphere Research Satellite) to demonstrate the utility of this data-model comparison. Similar to MIGHTI, WINDII measures Doppler shifts from a suite of visible region airglow and measures zonal and meridian winds, temperature, and VER (Volume Emission rate) in the upper mesosphere and lower thermosphere (80 to 300 km) from observations of the Earth's airglow. We will use a similar approach discussed for MIGHTI to calculate the vertical profile of Redline airglow, Wind velocity, emission rate and compare them with our simulated results to validate our algorithm. We initially thought asymmetry calculation along the Line of Sight (LOS) would be the limiting factor. We believe other things are going on such as variability in the winds associated with natural fluctuations in the thermosphere, atmospheric waves, inputs from the sun and the atmosphere below etc., that appear to be a more significant factor than just asymmetry along the line of sight.

The results of monitoring for the wind regime at heights of mesosphere – lower thermosphere by meteor radar of Kazan Federal University (56N, 49E) are presented. Typical height and seasonal regularities are established for zonal and meridional winds as well as tidal amplitudes.

Band selection study for SMILES-2 proposal (JAXA/ISAS 500 kg science satellite program) is updated from 4 bands configuration to 3 bands (625-650 GHz, 750-771 and 1.8- 2.0THz). This change is required to reduce sizes of primary antenna (from 100 cm to 2 , CO, CH 3 Cl, and B r O, is improved in the new 3 bands configuration.

The Superconducting Submillimeter-Wave Limb-Emission Sounder-2 (SMILES-2) is a satellite mission for observation of the stratosphere, mesosphere, and lower thermosphere with superconducting submillimeter-wave receivers, being proposed to the announcement of opportunity for M-class missions run by the Japan Aerospace Exploration Agency (JAXA). The SMILES-2 notable features are extremely high sensitivity and observation capability of atmospheric diurnal cycles. Those are requested from a scientific requirement for the investigation of the 4-D space-time structure of diurnal variations in the whole atmosphere. Such features require SMILES-2 to have 4–K cooled superconducting devices for high sensitivity and to be aboard a satellite platform on a non-sunsynchronous orbit. The mechanical 4–K cooling system is a power consuming instrument. Satellite on a non- sunsynchronous orbit gets a large sun-shade ratio in most of season, and has limitations of power supply to the mission instrument. The issue of the SMILES-2 mission design is mainly to fit the 4–K cooling system to the limited power resource of M-class satellite. This paper discusses our development status on designing the SMILES-2 mission payload. SMILES-2 will be proposed to JAXA in the beginning of the next year.

Based on data from ionosondes and the ECMWF ERA-Interim reanalysis, we investigated the causes of medium-scale wave-like disturbances in winter ionosphere caused by the atmospheric waves arising in high-speed jet streams in the stratosphere and mesosphere. Perturbations of the ionosphere are considered as the maximum electron density N m F2 deviations from the daily averages. According to the UARS mission measurements in 1991–1992, quantitative estimates were performed of the energy flux and air mass generated in the summer tropical stratosphere/mesosphere and flowing as jet streams to the polar region. Medium-scale wave-like movements in the stratosphere and lower mesosphere occur in the autumn–winter time (November–February) as a consequence of the shear-layer instability in a flat-layered jet stream. Partially, the disturbances’ spectrum is amplified when a wave propagates against the flux. The disturbances are transmitted to the heights of the lower mesosphere and higher in the form of internal gravity waves, appearing in the ionosphere as travelling ionospheric disturbances. According to data from the Irkutsk and Norilsk ionosondes, activity of the medium-scale wave-like disturbances coming from the stratosphere and mesosphere is comparable to that of geomagnetic disturbances in the ionosphere.

Meteor Radar is widely used to study Gravity wave (GW) variances and their Momentum Fluxes (MFs) at mesospheric altitudes. However, the accuracy of meteor radar observations of GWMF should be evaluated before they can be used for research applications. In this regard, the present study evaluates the meteor radar observations of GWMF obtained from Thumba [8.5°N, 77°E (2006- 2015)], Kototabang [0.2°S, 100.3°E (2002-2017)] and Tirupati [13.63°N, 79.4°E (2013-2018)]. These radars provide hourly zonal and meridional wind observations round the clock in 80-100 km height domain known as mesosphere lower thermosphere region. Three methods are employed to evaluate the meteor radar performance in estimating the simulated GWMFs, Viz., 1) Day by day analysis, which is traditional Hocking method 2) Composite day analysis and 3) Modified Composite day analysis. After evaluating these methods by employing GW simulations, it is found that modified composite day analysis shows good agreement and the same is used for constructing the GWMF climatologies over the observational locations. The significance of the present study lies in evaluating the three different methods for estimating GWMF by employing GW simulations and meteor radar observations.

The techniques of Active Space Experiments (ASE) include the particles injection and electromagnetic beams emission into geospace from ground or space. Based on the mechanism of the interaction between dusty particles and plasmas in ionosphere, this paper analyses the effect of particle shape on the charge effects of plasma. The processes of superfine particles injection and particle clouds formation are also discussed. This paper presents some results from theoretical analysis, experimental results and numerical simulations. The results show that the well-organized local space structure of nanoscale slender particles cloud display scattering effect to electromagnetic waves along with stronger electron adsorption capacity. The results also show that the nanoscale particles behave the shorter relaxation time than the microscale particles and in mesosphere a particles cloud of 800 meter scale can be produced using the injections method.

SMILES-2 is a proposed spaceborne mission using THz superconducting receiver for measurement of the Earth's atmospheric thermal limb emission. The mission concept is prepared for the call-for-proposals for JAXA/ISAS M-class scientific satellite mission. SMILES-2 will measure wind, temperature, atmospheric compositions in the stratosphere, mesosphere and lower thermosphere, and their diurnal cycles. Three-band receiver at 638 GHz, 763 GHz, and 2 THz can cover the unprecedented wide altitude range of wind and temperature observation. A technical concern of the mission is a large power consumption requirement to the resource of an M-class satellite orbiting a non-sun-synchronous orbit. Large power is necessary to operate cryocooler for cooling superconducting devices that work at temperature of around 4 K. We are studying measures to reduce the power consumption and enhance the feasibility of the mission.

The Global Navigation Satellite System (GNSS) radio occultation (RO) observation data is widely used for numerical weather prediction (NWP) and global climate monitoring (GCM). However, the residual higher-order ionospheric error (RIE) can still be significant. To further mitigate the RIEs, characterization and quantification of RIEs in bending angles have been performed by using end-to-end simulations. In this study, the seasonal characteristics of the RIEs in bending angles were analyzed by using larger ensembles of profiles from end-to-end simulations. The results indicated that the RIE is a major source of the bending angle in lower mesosphere and upper stratosphere (LMUS), and its bias has a clear negative tendency that in line with our previous studies. The preliminary analysis showed that, globally the average bias and standard deviation of RIEs changed slightly, while regionally they changed obviously. For the northern hemisphere middle latitude (NHM) region, the largest average bias and standard deviation of RIEs happened in summer, while the smallest ones happened in winter. This study helps to inform future RIE mitigation schemes for ensuring benchmark quality stratospheric RO data.

The Superconducting Submillimeter- Wave Limb-Emission Sounder 2 (SMILES-2) is a satellite mission to observe the stratosphere, mesosphere, and lower thermosphere with superconducting submillimeter receivers. SMILES-2 aims at studying the dynamical, chemical, and electromagnetic coupling of the middle and upper atmosphere with an unprecedented high-precision observations of multiple atmospheric parameters from a platform on a non-sunsynchronous orbit. SMILES-2 consists of superconducting receivers at frequencies between 619 GHz and 2.06 THz. The GHz receivers observe mainly the temperature, wind, and chemical compositions in the stratosphere and mesosphere. The frequency band of 640 GHz receiver includes the band investigated by JEM/SMILES mission, which was operated during the period from 2009 to 2010. The THz receiver, a new channel of SMILES-2, is devoted to measurement of atomic oxygen for observation of the lower thermospheric temperature and wind. The SIS mixer of GHz receiver and HEB mixer of THz receiver are cooled down to around 4 K by a mechanical cryocooler, which is designed to have 3 year lifetime and 5 year goal. The SMILES-2 payload is estimated to be less than 200 kg and consume power of 300 to 400 W. SMILES-2 is proposed for a mission installed on 500 kg size satellite of the Japan Aerospace Exploration Agency (JAXA).

The remote sensing technique using X band and K band microwave signals between two Low-Earth-Orbit(LEO-LEO) satellites can characterize atmosphere temperature, humidity and pressure from low troposphere up to mesosphere without auxiliary background information. This paper firstly introduces the principle of the technique and then our LEO-LEO occultation system is presented. To achieve demanded amplitude and phase measurement precision, the structure and features of the LEO-LEO receiver are introduced. The transmitter and receiver have been basically completed. The ground test will be done within a few months.

Aerosol content and temperature are important parameters of the Earth’s stratosphere and mesosphere. We present the results of many years and present-day investigations of this high–altitude atmospheric region using Rayleigh and Raman lidars (Tomsk, Yakutsk and Kamchatka).

The MU radar was built in 1984 as the first large-scale MST (Mesosphere, Stratosphere, and Troposphere) / IS (Incoherent Scatter) radar with a two-dimensional active phased array antenna system by Kyoto University with the collaboration of Mitsubishi Electric Corporation. IEEE Milestone was dedicated to the MU radar in 2015. This article describes the history of development of the MU radar, its historical and technological significances, influence to the subsequent system, continuous research and development towards the future, and the milestone dedication.

Polar Mesosphere Summer Echoes (PMSE) are strong radar echoes that have been observed typically by the VHF radar in summer polar mesosphere and have closely relation with charged dust particles. Theoretical analysis and extensive experimental data show that polar mesosphere summer echoes (PMSE) present some kind of regular periodic changes, such as semidiurnal variations, diurnal variations, day-to-day variations, seasonal variations, year-to-year variations, obvious layered phenomena and so on. To obtain the trends of PMSE occurrence rate with different layers, data detected by the European Incoherent Scatter Scientific Association (EISCAT) VHF radar in 12 years is used to analyze corresponding PMSE occurrence. The year-to-year variations of PMSE occurrence rate with one-, two- and triple-layered are given, and the effect of geomagnetic activities are discussed in the paper. The results indicate new recommendation for studying PMSE in the future.

From EISCAT VHF radar observations it is evident that polar mesosphere summer echoes (PMSE) often show obvious layers. PMSE overshoot describe the effect of dusty plasma parameters on overshoot characteristics curve. In this paper we obtain and compare different PMSE overshoot characteristic curves (OCCs) at 80–85km and 85–90km in one hour respectively, from based on the data observed by EISCAT 224 MHz VHF radar on 12 July 2007. The relate intensity of PMSE on the moment when the heater off show some different characteristics in different PMSE layers.

Polar summer mesopause region belong to dusty plasma, the impact of dusty plasma on the electromagnetic signals have been verified by lots of experiments. If the system of space microwave energy transmission will be used in high latitudes of both hemispheres in the future, we need to pay more attention on dusty plasma in polar mesosphere. In the paper we will discuss signal effect of polar summer mesosphere dusty plasma on space microwave energy transmission.

With the development of global navigation satellite system (GNSS) remote sensing, radio occultation (RO) has become an important atmospheric observation technique that mainly be used for numerical weather prediction (NWP) and global climate monitoring (GCM). However, residual ionopheric error (RIE) can still be significant after an ionospheric error elimination by linear combination of dual-frequency RO bending angles. Lots of quantification and analysis of RO bending angle RIEs has been conducted by using quasi-realistic end-to-end simulations. In this study, the RIEs in RO observations have been investigated by comparative analysis of COSMIC RO measurements and ECMWF model data. The results illustrate that the RIE is a major source of the bending angle in lower mesosphere and upper stratosphere, and its bias has a clear negative tendency that in line with our empirical studies based on simulation RO data. This study helps to inform future RIE mitigation schemes for ensuring benchmark quality stratospheric RO data.

Temperature, wind speed, H 2 O, and O 3 retrieval performance in the upper stratosphere and mesosphere was estimated using 485–489 GHz sub-mm limb sounder with 500 kHz resolution (2.5 kHz resolution for wind speed). Two instrument, one is 4K-cooled successor of SMILES, and the other is a compact room temperature instrument, are considered. Temperature can be retrieved within 2K precision at 15–100 km (4K cooled) and 18–85 km (room temp). Wind speed can be retrieved within 2 m/s at 40–100 km (4K cooled) and 50–90 km (room temp). H 2 O can be retrieved within 5% at 20–80 km (4K cooled) and 20–70 km (room temperature).

The EISCAT HF ionospheric heating facility has recently been upgraded in several key areas that allow more flexibility in changing parameters such a frequency, power and phase, as well as allowing an HF radar receiver operation. These new capabilities were important for several recent results some of which are presented here. The HF radar capability has been used successfully to study how mesospheric echoes at 8 MHz are affected by artificial electron heating. Attempts have also been made to search for 8 MHz magnetospheric echoes related to auroral processes, without obvious success so far. The more traditional F-region HF-pumping experiments have shown some unexpected results, especially during X-mode heating. These include the production of electron density striations, airglow, enhanced plasma and ion lines measured with the UHF incoherent scatter radar, and electron temperature increases, phenomena which are normally expected to occur only with O-mode heating. For O-mode we sometimes see a descending HF-induced ion line which is most likely due to ionization from pump-induced fluxes of suprathermal electrons. Quantitative comparisons between measurements of electron heating and models of Ohmic and resonant heating have been made, and comparisons between the observed and theoretical thresholds of the various plasma instabilities. Furthermore, there are often unexplained 933 MHz radar backscatter enhancements above the HF reflection height, seen with both polarisations but only in directions very closely aligned along the magnetic field.

In this paper we report atmospheric wind variations during the 2013 major sudden stratospheric warming (SSW) event at Langfang (39.4°N, 116.7°E). The wind measurements by Langfang meteor radar and UK Meteorological Office (UKMO) wind data are combining used to present their anomalous behaviors response to the event. These winds reveal significant anomalies in the mesosphere and lower thermosphere (MLT) zonal wind over mid-latitude corresponding to the 2013 major warming by comparing to the observations in 2010/2011 when no major warming occurred and could be considered as the normal condition. Results show that the westward wind at 60°N during 2013 major SSW was first observed between 40 km and 53 km and then extended to lower stratosphere and mesosphere. Over mid-latitude, the eastward wind reversed to westward during January 4–15, 2013 at about 80 km with the maximum value of 48.4 m/s on January 11 by UKMO data, while the reversals of MLT daily mean zonal wind persisted from January 8 to 14 observed by meteor radar with the maximum value of 40.2 m/s at 98 km also on January 11. The period of this wind reversal and the date of the maximum wind actually coincide with the mesospheric response at high latitude to the 2013 major warming. These observations and analysis document clearly the impact of a major SSW on the MLT dynamics over the mid-latitude.

We present the use of VLF radio data to study the short-period (∼min to hrs) GWs and long-period (∼days) PWTOs. To show the presence of GWs, we analyse the VLF data from several places obtained by ICSP-VLF network during the solar eclipse of July, 2009. We find dominant wave periods ranging from 10 minutes to 1 hour around the time of maximum eclipse phase which could be associated with atmospheric gravity waves excited due to the solar eclipse. We also analyse nearly 4 years of VLF amplitude data received at ICSP, Kolkata from the VTX (18.2 kHz) transmitter and also from the NWC (19.8 kHz) transmitter for planetary wave type oscillations (PWTOs) in the mesosphere-lower ionosphere system. Fourier and wavelet analysis show the presence of PWTOs in both the radio paths having periodicity in the range 5–27 days. The PW spectrum of VLF data are also correlated with the PW spectrum of Ozone data.

The volume reflectivity and the irregularity of electron density occurring Polar Mesosphere Summer Echoes (PMSE) have close relation. A preliminary result is given by analyzing the data obtained from the experiment of ECT-02. The small-scale structure of electron density caused by charged dust particles may have some great effect on PMSE.

Ozone is one of the most important minor gas constituents of the atmosphere. Global depletion of the protective ozone layer in the last decades accompanied with such anomalous events as ozone holes in Antarctic and Arctic [1, 2] requires reliable long-term monitoring of ozone and ozone-related minor atmospheric gases from both satellites and ground level. Ground-based millimeter-wave (MMW) monitoring of atmospheric ozone is low-dependent on weather conditions, covers broad altitude region from the lower stratosphere to mesosphere, and is possible in day and night time [3, 4]. These features of MMW measurements provide their advantages over traditional optical methods (UV spectrometers and lidars) and ozone sondes.

The study of response of the middle atmosphere (stratosphere and mesosphere) to any external impact (variations of sunlight, flux of cosmic ray particles, eruptions of volcanoes, and anthropogenesis factors) is an urgent physical problem. Ozone and temperature are important atmospheric parameters. The correlation of these parameters is of significant interest from the viewpoint of thermal balance of the middle atmosphere. The basic heating of the stratosphere (altitude range of 20-50 km) is caused by absorption of solar ultraviolet radiation by ozone molecules. Thermal changes influence the rate of ozone formation and destruction. Other types of wave processes can redistribute the structures of vertical profiles of ozone and temperature in the middle atmosphere. Sudden stratospheric warming affects a lot of widely known atmospheric wave processes. Microwave radiometry and Rayleigh lidar allow investigation of ozone and temperature variations during large-scale wave disturbances in the middle atmosphere, such as, for example, stratospheric warming [1-3].

EOS Aura Microwave Limb Sounder data on the middle atmosphere parameters have been used for the numerical simulation of the lower ionosphere. Real data on the temperature, geopotential height, water and ozone content were processed using the Fast Fourier Synoptic Mapping technique, providing the two-dimensional field along the radiopaths from European VLF/LF transmitters to the geophysical observatory “Mikhnevo” (55N, 37E). These parameters have been used in the numerical simulation of the electron density distribution. The control run was evaluated using MSIS and AFGL empirical models. The resulted ionospheres have been used in the simulation of VLF/LF radiowaves propagation using LWPC code. We present the comparison between the lower ionosphere parameters derived from satellite data, calculated on the empirical atmosphere models and two pure empirical models, namely, IRI and the built-in LWPC model. The comparison has been done for various seasons, sunlit and nocturnal conditions. The synoptic reconstruction has proven the existence of significant periodic perturbations in the mesosphere, which are important for the LF propagation and confirmed the results of SAVNET group on the C-layer complex dynamics. The results of the VLF/LF propagation simulation in the frequency range from 19 to 77 kHz under four ionospheres are presented.

A simple method to confirm the dust charge number and the radius of dust particles in dusty plasma is deduced. Based on the orbit-limited motion method and the charging theory of dust particles in dusty plasma, the equation of dust particles charging is formed, and the formula of the ratio of dust charge number to the radius of dust particles is deduced. Based on the data of MD-06 campaign, the ratio of dust charge number to the radius of dust particles at occurring polar mesosphere summer echoes(PMSE) is analyzed. The dust charge number and the radius of dust particles are obtained. The results show that the average charge number of dust particles in the polar mesopause is less than one and the average radius of dust particles is about 20nm.

It is known that the formation of polar mesospheric clouds (PMCs) is correlated with temperature, concentration and desublimation nuclei of water vapor. The primary candidate of these nuclei is believed to be meteoric smoke particles. In this study, we have surveyed the influence of meteoric smoke particle attributions on polar mesospheric ice clouds formation. It is found that the large smoke particles with radium of 2–3 nm will dominate the nucleation of water vapor.

Performance of Superconducting Submillimeter-Wave Limb Emission Sounder (SMILES) onboard International Space Station was discussed from the analysis of random errors of Chlorine monoxide (ClO) in the stratosphere and mesosphere. Some lessons learned from the SMILES operation in space are discussed.

Coupling between the stratosphere/mesosphere and ionosphere during the January 2010 stratospheric warming event is analyzed using ground-based ionosonde, SATI from Alma-Ata [43.25°N, 76.92°E) and COSMIC/FORMOSAT-3 GPS observations.

This paper reports on the direct comparison between experimental and numerical results of the ionospheric disturbances associated with red sprites in the mesosphere. The ionospheric disturbances due to the sprite ionization column is observed by a continuous monitoring of the amplitude and phase of distant VLF transmitter signals at several locations in Japan, whilst the numerical computation to calculate the spatio-temporal dependence of the observed VLF waves is performed by using a two-dimensional finite-difference time-domain (FDTD) method. As a result, the observed maximum scattered amplitude and phase changes are in close agreement with the numerical results both for carrot and column sprites. The distance variation of the scattered amplitude from the numerical simulation is found to strongly depend on the spatial dimension of the sprite ionization column due to the different scattering mechanisms. The forward scattering amplitude is significantly larger than back scattering amplitude for the carrot sprite indicating the nature of Rayleigh scattering, while both backward and forward scatterings are comparable for a column sprite showing the nature of Mie scattering.

The EISCAT Svalbard Radar (ESR) was operated in a continuous mode during the International Polar Year (IPY), starting on 1 March 2007 and ending on 29 February 2008. The radar experiment was dedicated to ensure good coverage also in the ionospheric lower E and D regions, in addition to covering the more standard experiment target, the ionospheric F peak, and reaching into the topside ionosphere. By using this unique continuous dataset gathered during the solar minimum, we show that anomalous variability of the quiet daytime electron density in the D region can be explained by the varying NO concentration. Our focus is especially on September-October 2007, where the quiet daytime electron density suddenly increased by a factor of 7–10. This enhancement, most clearly seen at sunsets, lasted for several days. Using a detailed chemistry model we can show that an enhanced nitric oxide density explains the electron density at 92 km. This finding might provide aims to estimate NO from various quiet daytime electron density measurements in the upper mesophere-lower thermosphere.

Considerable quantities of small dust/aerosol particles of meteoric origin are present in the mesosphere at all heights and latitudes. These particles have a role to play in various aspects related to both physics and chemistry of the region. Due to electron attachment and photoionization these particles can produce electron density fluctuations that lead to an enhancement in the MST radar echo strength. Due to electron/ion-attachment the dust/aerosols can considerably alter the electrical conductivity of the mesosphere. The charge separations produced by the falling charged dust/aerosol particles can lead to the often-observed high electric fields, particularly in the lower mesosphere. In the present study, using a heterogeneous ion-chemistry model [1], the possibility of the influence of positively and negatively charged sub-visible particles (1–30 nm) on the electrical conductivity and MST radar echo enhancements are studied. The results are for an equatorial quiet daytime mesosphere in the height range of 60 to 90 km.

The Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) observes vertical profiles of atmospheric minor constituents related with stratospheric and mesospheric chemical processes. The retrieved profiles contain some error originated from the response characteristics of radio spectrometers of the SMILES instrument. The on-orbit properties are necessary to be characterized and be modeled, in order to minimize the retrieval errors.

The Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) observes O3 and other minor chemical species in the stratosphere and mesosphere. Limb observation of SMILES is sensitive to the quality of the tangent altitude retrieval. To obtain better retrieval result, knowledge of initial tangent height and antenna pattern should be as precise and accurate as possible. It was concluded that initial tangent height is calculated by using ISS attitude and mirror pointing angle, and ISS position. Antenna pattern assuming 6 points moving average was applied to the retrieval and showed reasonable results.

The experiments show that polar mesosphere summer echoes (PMSE) and polar mesospheric winter echo (PMWE) are both related to the existence of dust particles. For the sake of finding the appropriate theory of the abnormally phenomenon taking placed in the mesosphere atmosphere, it is all-important to study the conductivity and permittivity of dust plasma there. We have studied the conductivity and permittivity of dust plasma in polar mesosphere based on the theory of dust plasma, under the cases of ignoring the magnetic field and considering the electron -neutral collision and the electron -dust charging process. The curves of the conductivity-high and permittivity-high have been obtained by substituting the test data into the formula of conductivity and permittivity of the dust plasma. We compared the curves of charging response factor-high and the SNR-high, which show that PMSE has a great relation to dust particle charging process.

The MF radar developed for remotely probing the near-Earth space environment and the technique for diagnosing plasma parameters in the electrically active mesosphere have enabled the determination of the basic electrodynamic characteristics of this region, which are required for achieving the fundamental physical understanding and can be used in practical applications (Sun-Earth connections, modeling the ionosphere as well as natural and anthropogenic global disturbances, near-Earth environment monitoring, earthquake predictions, and radio propagation forecasting). In particular, the average daily electric fields intrinsic to the mesosphere have been determined for the first time.