*******   P W S  data format description   *******



  PWS  (plasma  waves  and sounder experiments) onboard the  Akebono  (EXOS-D)

satellite 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). In the present database system, electric field intensity  data

observed by NPW sub-system represented by 8 bits digit (i.e. 0 - 255) has been

stored for every 8 seconds in a following format :



  1) File name :  yymmddhh.pws ( same as other PI data file name )



  2) 1  block  data (120 sec data, 3841 bytes)  consist of  sequential  record

number (1 byte) and 15 data sets corresponding to the every 8 seconds interval

observations.  The first block contains no observation data but start time  of

the  observation and the additional comments on the carrying out  observation,

if necessary, in ASCII code.





  3) Each  data set (256 bytes) consists of  256 points of  observation  data;

each  data point consists of 1 byte integer without sign bit. Each data  point

in one data set represents electric field intensity at a given frequency  with

the  band width of 1kHz. The frequency variation in each data block  is  given

with linear function of corresponding step number; i.e. 

                data block 1 (step 1 - 64)      :   20kHz -  140 kHz

                data block 2 (step 65 - 128)    :  140kHz -  380 kHz

                data block 3 (step 129 - 192)   :  380kHz - 1340 kHz

                data block 4 (step 193 - 256)   : 1340kHz - 5120 kHz.

        

  4) If  there is  no observation data, record of each data set is given  with

null code.



  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 onboard the EXOS-D  satellite.  Before  the

presentation  of  the result in meeting, journals etc. using PWS data,  it  is

also required to send abstract or paper to: 



                     PI:   Hiroshi Oya

                           Department of Astronomy and Geophysics,

                           Tohoku University

                           Sendai, 980, JAPAN

                           Tel. 022-217-6514    Fax. 022-217-6517

                           E-mail  THKSTP(40.799)::Oya   (DECNET)

                                   Oya@stpp.geophys.tohoku.ac.jp (INTERNET)



  For the detail information on PWS database, contact to:

                           Masahide Iizima

                           Department of Astronomy and Geophysics,

                           Tohoku University

                           Sendai, 980, JAPAN

                           Tel. 022-217-6516    Fax. 022-217-6517

                           E-mail  Iizima@stpp.geophys.tohoku.ac.jp (INTERNET)



Reference 



Oya, H, A. Morioka, K. Kobayashi, M. Iizima, T. Ono, H. Miyaoka, T. Okada and

  T. Obara,  Plasma wave observation and sounder experiments (PWS) using  the

  Akebono (EXOS-D) satellite - Instrumentation and initial results  including

  discovery  of  the high altitude equatorial plasma turbulence,  J.  Geomag.

  Geoelectr., 42, 411, 1990.