The S-520 is a powerful single-stage rocket which is optionally equipped with three-axis attitude control and a recovery system. It has a capability for launching a 100 kg payload far above 300 km and provides more than five minutes of micro-gravity flight environment.

The S-520-29 sounding rocketrocket was launched from Uchinoura Space Center, Japan (31.3°N, 131.1°E) at 10:10 UT on 17 August 2014 for the purpose of stereoscopic observation of sporadic E-layer spatial structure.

Number Density Measurement of Electrons by Impedance Probe (NEI)

The NEI (Number Density Measurement of Electrons by Impedance Probe) is an instrument designed to determine the electron number density. It measures the impedance of a 1.2-meter probe extended into the ionospheric plasma across a frequency range from 0.1 to 25 MHz. The following datasets are publicly available for scientific use:

1. Spectrogram of Probe Capacitance:

   • File: s_520-29_nei_c_v01.cdf
   • Details: This data captures the capacitance of a probe within the ionospheric plasma across 394 frequency steps from 0.1 to 25 MHz, recorded at intervals of 129.7 milliseconds.
   • Format: CDF

2. Electron Number Density:

   • Files:
     • Ascent phase: s_520-29_nei_ne_a_v01.txt
     • Descent phase: s_520-29_nei_ne_d_v01.txt
   • Details: Electron number density derived from probe capacitance measurements taken during the ascent (X < 248 seconds; X is the time from the launch) and descent (X > 248 seconds) of the sounding rocket.
   • Format: Text with columns below.

     TIME(sec): Time from the launch [sec]
     LAT(deg): Geodesic latitude of the rocket [deg]
     LON(deg): Geodesic longitude of the rocket [deg]
     HEIGHT(km): Height of the rocket [km]
     FC(MHz): Electron cyclotron frequency [MHz]
     FUH(MHz): Upper hybrid frequency [MHz]
     FP(MHz): Plasma frequency [MHz]
     NE(/cc): Electron number density [/cc] 
     

Ancillary Data

1. Location Data:
   • File: S-520-29_LatLonHightDR.txt
   • Details: Latitude, Longitude, and Altitude data of the rocket.
   • Format: Text