RAV Data Files
RAV files contain data from the
URAP RAR instrument that has been averaged over a
144 second period. This period is the shortest one
that contains data from all of the frequency channels
when the RAR is operating in its normal configuration.
Data from all of the frequency channels, both high
and low band, are included, so there are 64+12=76 channels.
Each file covers a single data. The data files are Ascii
text files with data for each 144 second period (600 per day),
even if there were no valid data for one or more periods. Invalid
or missing data are indicated by a value of -99.0. All valid
data are positive in value. The format of the data is as
follows:
RAR RAV output file format
Each averaging period contains the following information
which was written using the
Fortran format statement:
(I4,2I2.2,1X,3I2.2,1X,5I2,/,(1P6E12.4)).
| NAME |
DESCRIPTION |
| YEAR | Date and time of the
averaging interval |
| MONTH |
| DAY |
| HOUR |
| MIN |
| SEC |
| LO_POL_MODE |
Low band polarization mode:
| 1 | 2 |
3 | 4 |
| On | Off |
Switch | Unknown |
|
| LO_SUM_MODE |
Low band summation mode:
| 1 | 2 |
3 | 4 |
| Summed | Separate |
Switch | Unknown |
|
| HI_POL_MODE |
High band polarization mode:
| 1 | 2 |
3 | 4 |
| On | Off |
Switch | Unknown |
|
| HI_SUM_MODE |
Low band summation mode:
| 1 | 2 |
3 | 4 |
| Summed | Separate |
Switch | Unknown |
|
| KBPS |
Bit rate flag:
| 1 | 2 |
3 | 4 |
5 | 6 |
| 128 | 256 |
512 | 1024 |
Swtich | Unknown |
|
| DATA |
Data for each frequency, both low and high bands, from
the low frequency (1.25 kHz) to the high frequency (940 kHz).
|
Meaning of the data entries
- Date/time
- These data give the date and time of the beginning of the averaging
interval. They start at 000000 of each day and increase by 144 seconds
for each period.
- LO_POL_MODE
- This flag indicates the state of the low band polarization - that is
whether phase-shift is introduced into the signal of the Z antenna so that
the polarization state of the incoming radiation can be measured.
The value 3 for this flag means that the value switched during the averaging
period and thus some of the data accumulated was in polarized mode and
some in unpolarized mode. The value 4 indicates that the value could not
be determined for some reason - usually due to missing or corrupted data.
- LO_SUM_MODE
- This flag indicates the state of the low band summation - that is whether
the signal from the Z antenna was added to the signal from the X antenna to
produce a synthesized signal simulating an antenna tilted at an angle to the
rotation axis of the spacecraft. When in summed mode, a more accurate
determination can be made of the source direction.
- HI_POL_MODE
- This flag is similiar to the LO_POL_MODE but applies to the
high frequency receiver (frequency channels 64-75).
- HI_SUM_MODE
- This flag is similiar to the LO_SUM_MODE but applies to the
high frequency receiver.
- KBPS
- This flag indicates the telemetry bit rate that the Ulysses spacecraft was
operating at when the data were taken. The configuration and capabilities
of the URAP
instruments changes with the bit rate. For instance, measurement of polarization
of radio signals can only be measured at the highest bit rate (1024).
- DATA
- These are the averaged data from the radio receiver. There are 76 channels
(numbered 0 to 75)
going from 1.25KHz to 940KHz in order. There are 6 channels per line in the
file, with 4 channels in the last line.
Updated 2005-10-17