PDS_VERSION_ID = PDS3
RECORD_TYPE = STREAM
OBJECT = TEXT
INTERCHANGE_FORMAT = ASCII
PUBLICATION_DATE = 2008-07-29
NOTE = "BROWSE directory content"
END_OBJECT = TEXT
END
The BROWSE directory contains Quick Look Browse Plots of the data. The plots
are available as jpeg (*.JPG) files. There may also be postscript versions of
the plots (*.AUX). The plots are accompanied by a single label file of the
same file name but with extension *.LBL.
The files contain either quick look views after early processing of raw data
(RSR i.e. Radio Science Receiver data) or quick look plots of calibrated level
2 data (IFMS). These may be useful in identifying data which deserve more
detailed inspection. Certain data anomalies can be readily seen in the plots.
More details are given in the label file (*.LBL) of each plot.
JPEG files contain several figures generated from level 2 Doppler data after
processing and calibration. These may be useful in identifying data which
deserve more detailed inspection. For example, by looking at the JPEG file,
the user can determine whether a signal was easily detectable or whether the
data were corrupted. Certain data anomalies can be readily seen in the plots.
AGC that is the Auto Gain Control [dB] corresponds to 'SIGNAL LEVEL' in the
LBL file accompanying the level 2 data. Also calibration [Hz] corresponds to
'CORRECTION OF EARTH ATMOSPHERE PROPAGATION'. Residuals [Hz] correspond to
'RESIDUAL CALIBRATED S or X-BAND FREQUENCY SHIFT'. Differential doppler [Hz]
is computed by F_s - (3/11)*F_x, where F_s and F_x are the received signal
frequencies at S- and X-bands, respectively. The differential doppler is not
computed in case of a sampling frequency less than 1 per second. The plots of
the frequency residuals and differential doppler are divided into three plots
with shorter consecutive time periods.
The panels are arranged in the following way and can be easily identified
by the title on top of it. The plots were generated using gnuplot. Thus
the numbers in the upper right corner in each plot thus not give a ratio
but the number of columns plotted against each other. I.e. using 1:2 means
that the first column of the plotting data set was plotted against the
second column.
However this plotting data set is a subset of the complete data set given
in the corresponding level 2 data file. The raw data set contains not all
columns of the level 2 data. For example not all time columns were used
since only time in UTC was needed. In the filtered plots some data points that
were identified as cycle slips were removed. To see which columns of the
level 2 data was used for plotting compare the description given below
with the corresponding lebel 2 data label file.
Plot 1: Auto Gain Control in dBm vs UTC time (hours of the DOY of
measurement)
Sometimes no Auto Gain Control (AGC)-files are available.
In that case no AGC is plotted.
Plot 2: Calibration in Hz vs UTC time (hours of the DOY of
measurement)
Plot 3: Complete Residual of observed and predicted Doppler shift [Hz]
vs UTC time (hours of the DOY of measurement). If the predicted
frequency (Column 10 in level 2 file) is not given a residual
calibrated frequency shift is not computed and the plot is
therefore missing in the panel.
Plot 4: Complete Differential Doppler [Hz] vs UTC time
(only available if both X- and S-Band was recorded at a sampling
frequency higher than 0.1 Hz) (hours of the DOY of measurement).
Plots 5-7: The complete residual (above) was subdivided into three plots
in order to better identify smaller fluctuations which would
otherwise not be seen in the complete plot. Plots which contain
'filtered' data are cleared from cycle-slips.
Plots 8-10: The complete differential Doppler (above) was subdivided into
three plots in order to better identify smaller fluctuations
which would otherwise not be seen in the complete plot.
Plots with extension 'filtered' are cleared from cycle-slips
using scripts.