Plasma Waves and Sounder experiment (PWS)

Data

PWS (plasma waves and sounder experiments) has three sub-systems; i.e. i) a sub-system for natural plasma wave observations (NPW), ii) a sub-system for stimulated plasma wave experiments (SPW) and iii) the instrumentation for measurement of the number density of electron (NEI). The following data are open to the public for scientific use. All the files from 1989 to 2015 are available.

For effective utilization of PWS data and responsible publication, the user is requested to refer to Oya et al. [1990] for further detail specification and descriptions on PWS experiments.

If you have any questions, please contact Akebono/PWS Data Manager.

Akebono/PWS Data Manager:
Dr. Atsushi Kumamoto (kumamoto (at) stpp.gp.tohoku.ac.jp)

The electric field intensity spectrum data

The electric field intensity spectrum data of 2 seconds time resolution observed by NPW sub-system. Each data point consists of 512 electric field intensity in a frequency range from 20 kHz to 5.12 MHz with a band width of 1 kHz. The frequency variation in each data block is given with linear function of corresponding step number.

data block 1 : 20kHz - 140 kHz
data block 2 : 140kHz - 380 kHz
data block 3 : 380kHz - 1340 kHz
data block 4 : 1340kHz - 5120 kHz

The data files are provided in the CDF format.

The electron number density data

The electron number density data of 30 seconds time resolution derived from the resonance frequency of the upper hybrid resonance (UHR) waves found in the electric field intensity spectrum data. The data files are provided in the text format. Please check README.txt also.

The Poynting flux data

The waveforms of two electric field components (E1 and E2) and three magnetic field components (B1', B2', and B3') of radio and plasma waves observed by NPW sub-system. Each waveform data consists of 50 data points sampled from IF signal with center frequency of 1 kHz and band width of 100 Hz, which are converted from 8 frequencies from 59 kHz to 1.3 MHz. The sampling frequency is 5 kHz. The directions of the five electromagnetic fields change depending on the time due to the spacecraft spin. So, some matrixes for conversion from antenna's coordinate system to equatorial coordinate system are also provided in the same data file. As for usage of them, please check README-PY.pdf also. The data files are provided in the CDF format.

The topside ionogram data

The topside ionogram data observed by SPW sub-system operated in n2, n3, and h3 modes. The frequency range, number of frequency step, sweep period, range resolution in vacuum, and number of sample data in these mode operations are as follows:

Mode	Frequency range	Frequency steps	Sweep period	Range resolution	Echo samples
n2	20 kHz - 890 kHz	256	16 sec	18 km	128
n3	20 kHz - 890 kHz	256	16 sec	9 km	128
h3	300 kHz - 11.4 MHz	512	32 sec	9 km	128

The data files are provided in the CDF format.

TDAS load procedure

Here, you can find a TDAS load procedure file for PWS electric field intensity spectrum data. PWS electric field intensity spectrum data analysis becomes available on TDAS with this load procedure. TDAS (THEMIS Data Analysis Software suite) has been developed by THEMIS project. See TDAS web page for details.

Data Policy and Credits

In order to confirm the reliability of the data, you are requested to contact the PWS data manager, Dr. Atsushi Kumamoto at Tohoku University before using the PWS data in oral/poster presentations. In the publishment, You should contact to the PWS data manager, Dr. Atsushi Kumamoto at Tohoku University before the submission for the confirmation of the principle of authorship/acknowledgement. You are also requested to send reprints to the PWS Data manager.

In any publications, the use of the Akebono/PWS data should also be acknowledged, for example, as "The Akebono/PWS data were provided through DARTS at Institute of Space and Astronautical Science, JAXA."

Contact

Dr. Atsushi Kumamoto: Tohoku University
Aoba, Aramaki, Aoba-ku, Sendai, 980-8578, Japan.
E-mail: kumamoto AT pparc.gp.tohoku.ac.jp