The ONR-602 experiment on board the S81-1 US Air Force mission was used, as one of its objectives, to investigate the global precipitation of radiation belt particles at low altitude. The experiment consisted of two particle telescopes—the main telescope and the monitor telescope. The main telescope performed Pulse-Height Analysis (PHA) on a priority basis set by the triggering of specific logical combinations of detectors to determine the charge, mass and energy of events, and returned detector coincidence and singles counting rates. Detector coincidence counting rates were formed by various logical combinations of the detectors, and singles counting rates were simply individual detector's counting rates. The monitor telescope had a fully depleted Si detector, and was designed to return only high counting rates of protons (0.6-9MeV), alpha particles (0.8-4.5MeV/n), and Z>2 particles (1.1-11MeV/n). The three rates were corresponding to the three discriminator thresholds—ML (0.36MeV), MM (2.80MeV), and MH (10.50MeV) for the pulse height analyzer of the single Si detector. The monitor had the peak efficiency of detecting particles of -90° pitch angle near the equator, and due to the wide opening angle of 75° it could detect quasitrapped particles of all pitch angles satisfying the energy thresholds in the altitude of interest. The high energy cosmic ray background count by the monitor was very insignificant. The procedures of handling data for the equatorial zone (±30° geomagnetic latitude) has been presented. Careful separation of particle precipitation data during geomagnetic average condition for the equatorial zone from other zones, and subsequent analysis show that ML rates were almost entirely due to protons.

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Precipitation of low energy protons (-1MeV) at low equatorial altitude has been investigated by the Phoenix-1 experiment on board the S81-1 mission. Results of the analysis of data received by the monitor telescope and their geophysical interpretation are presented. Seven months long observation during geomagnetic average conditions in May through early December of 1982 shows that the peak precipitation of protons occurs along the line of minimum magnetic field strength. The full width at half maximum (FWHM) is nearly 13°. The particle flux shows a strong altitude dependence, and below 220km it shows double peak structures. Spectral index of the precipitation flux has been obtained from the data of previous observations. Further, peak precipitation flux in 1982 is almost three times as large as peak precipitation flux in 1969. Charge exchange mechanism favors a stronger source than AP8MAX model. Particle flux does not depend on geomagnetic longitudes. Finally, investigations into the presence of Z≥2 particles show that they are virtually absent in the energy range considered.

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HF Doppler variations caused by ionospheric disturbances are studied using an ionosphere model containing sinusoidal traveling electron density fluctuations. The present study is different from earlier works in that we use a more realistic ionosphere model and a more accurate numerical method than previous works using corrugated specular reflector models. Our study gives a clue to estimate the TID-associated fluctuations of Ionospheric electron density by means of HF Doppler measurements. It is shown that some kinds of characteristic HF Doppler traces result depending on the wavelength of the disturbance and its traveling direction. Numerical results suggest that more or less 5% of the background electron density can explain most of the quasi-periodic variations on the observed HF Doppler records.

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A new experimental method for preparing ultrafine iron sulfide grains is proposed. Troilite, marcasite and pyrrhotite grains predominantly, were produced by the coalescence between solid iron grains and liquidus sulfur grains at temperatures above 100°C. Troilite and marcasite grains were grown as single crystals of a complicated polyhedral shape. Pyrrhotite grains exhibited a typical DDSS (diffusion-dependence shell structure) shape produced by the diffusion of iron atoms to the surface layer. Iron grains covered with a thin sulfur layer were observed among the collected grains produced at the temperature of 50°C.

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A rapid modeling method for a two-dimensional magnetic anomaly profile is formulated based on an inversion technique. This method gives the undulations of the top and bottom boundaries of a source body directly from a magnetic profile. The band passed or filtered anomalies are inverted to the configuration of the upper and lower boundaries of the causative magnetic layer. This initial model is then approximated by a sequence of two-dimensional tabular bodies for quantitative evaluation of the model. The effectiveness of this method is demonstrated through its application to the continental linear anomaly in northeast Japan, the seafloor spreading anomalies in the northwestern Pacific, and the anomalies associated with a nonuniformly magnetized seamount.

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Crustal magnetic anomalies in the Antarctic region were studied with the MAGSAT CHRONFIN data of 1790 passes.
The GSFC(12/83) model was used to reduce the earth's core field to estimate the residual magnetic field. Obtained residual intensity data in the geomagnetic coordinates were averaged over 1 hour magnetic local time (MLT) and 1° invariant latitude, and then grouped by taking the planetary magnetic activity index (K_p) as a parameter to derive the Mean Polar Disturbance Fields (MPDFs).
The obtained MPDF for K_p=2₀, for example, amounts to 50nT at 85°S and decreases monotonically toward lower latitudes on the dawnside. On the duskside, the MPDF takes a small value of 10nT at 85°S, decreases to a negative peak of -30nT at 78°S, recovers to a smaller positive peak of 20nT at 62°S, and then decreases to zero at further lower latitudes. These characteristic features of the MPDF are attributable to the external fields produced by S_q^p currents with occasional eastward electrojet in the ionosphere, which are superimposed by the magnetic field due to the westward ring current in the magnetosphere.
The MPDFs for K_p values from 0₀to 2₀ were subtracted from the residual intensity data, and the resultant data were averaged for 3° by 3° in latitudes and longitudes to obtain crustal magnetic anomalies at a mean altitude of 450km. The anomaly contours at an interval of 2nT reveal long-wavelength (-500km) crustal magnetic anomaly patterns with a clear correspondence to geologic provinces.
The anomalies in the oceanic area are negative for abyssal plains, while they are positive for ridges and plateaus. The tectonically active Scotia Sea microplate region is associated with negative anomalies. Land areas of Antarctica are characterized by three positive anomalies over Enderby Land, Gamburtsev Subglacial Mountains and Wilkes Land. Negative land anomalies are also definitely related to geologic provinces such as Queen Maud Land, Queen Mary Land, etc., but a detailed interpretation of overall magnetic anomaly pattern requires more comprehensive geological and geophysical studies.

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Localized energetic electron precipitations have hitherto been observed. Flux enhancement of energetic electron precipitations induced by loss cone angle increment and energy gain of the trapped electrons due to the field-aligned electric field was quantitatively estimated. It is possible that the localized energetic electron precipitations are caused by the localized field-aligned electric field.

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