Suncal Configuration File
The Suncal utility uses information within the suncal.conf file stored in the ${IRIS_CONFIG} directory.
You can adjust your configuration by editing
this file with a text editor such as emacs or vi.
In the file users, you can add details of the scanning strategy, data output directories, whether to create a log file, and IRIS messaging signal thresholds.
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Optional sun simulation is built in to the utility to help testing. You must turn this off for operation. |
Running the Suncal utility with the –resave option reads in the old suncal.conf file, fills in all new fields with default values, and writes out the file including comments.
You can run suncal -resave when there is no file to create a default file.
It is a good idea to do this also when you are first using Suncal after an upgrade. The user can then change parameters within the suncal.conf file to suit their needs. When designing the sector task, remember that tasks are limited to 40 elevation angles.
Configure Logging
The options to create logging while the Suncal utility runs, the source of the angle tags, simulation, and minimum sun angle are at the top of the file.
If you wish to run with radiate turned off, and your RVP processor does not sense the radiate control signal, then it faults with burst pulse missing. To allow operation in this case, set lAbortOnMessages to 0.
sun_cal.sVersion = "8.12"
sun_cal.lLogToFile = 1
sun_cal.lLogToTerm = 0
sun_cal.lAbortOnMessages = 1
# 1=RVP Tags, 3=Antlib.The Suncal utility also checks the elevation angles to ensure they are not outside the position limits of the antenna. A maximum sun angle of 85° has been hard coded into the utility.
The following example shows an excerpt of the suncal.conf file where these fields are configured.
sun_cal.iAngleSource = 1
# Add a simulated sun, set to 0 for operation.
sun_cal.lSimulateSun = 0
# Will not run if the sun is below this angle in degrees.
sun_cal.fMinimumSunEl = 5Configure PRF, Start Range, Range Bin Spacing, Input Bins, and Pulse Samples
In the following section of suncal.conf are the options to configure the PRF, start range, range bin spacing (km), number of input bins, and pulse samples.
We suggest that you select a fairly large start range (like 100 km / 62.1 mi) to avoid interference from weather, clutter, and airplane returns. The azimuth scan speed is half that implied by the requested PRF and sample size. If you have a dual-polarization radar, you configure the transmit polarization here. You must specify a valid polarization which you can transmit.
# Configure the recording task here.
sun_cal.fPrf = 800
sun_cal.fRangeStart = 100
sun_cal.fRangeStep = 0.150000006
sun_cal.iBinCount = 1000
sun_cal.iSampleSize = 64
# Choices are 0=Horiz, 1=Vert, 2=Alt, 3=Simul.
sun_cal.iTaskXmtPolarization = 0Configure Resolution and Sector Span
In the next section the resolution and sector span are configured for azimuth and elevation in degrees.
# Spacing between rays in degrees.
sun_cal.Az.fSpacing = 0.200000003
# Span of the sector in degrees.
sun_cal.Az.fSpan = 8
# Spacing between rays in degrees.
sun_cal.El.fSpacing = 0.200000003
# Span of the sector in degrees.
sun_cal.El.fSpan = 8Configure BEAM Products
Next we configure the BEAM
products.
Specify a directory to write the BEAM products. If the
BEAM product is added to the ${IRIS_PRODUCT}
directory it is eventually removed by the watchdog process.
It is often a better choice to put the BEAM product somewhere else so it
is retained for future reference.
To view the BEAM product in the QLW, then a nice plan is to place this in
the /usr/iris_data/input directory, and configure a blank input pipe to
read them.
# Configure the BEAM product here.
# Write the beam products to this directory.
sun_cal.sBeamDirectory = "/usr/iris_data/input/"
If you wish to make an LDR calibration from the sun, then specify a second
BEAM product data type. Choices are to transmit horizontal, and generate
LDR, or transmit simultaneous and generate ZDR. You should be able to get both the LDR
offset, and the vertical position offset. If you wish to calculate the vertical beam width,
run a vertical polarization scan.
# Second BEAM data type: 0=none, 25=LDR, 5=ZDR
sun_cal.iBeam2DataType = 25The final section of the
suncal.conf file configures the processing to produce the results
from the BEAM products.
# Configure the results processing here.
# Write the results file to this directory.
sun_cal.sResultsDirectory = "/usr/iris_data/suncal/"
# Power above this level (in SNR)
sun_cal.fBeamPower = -2
# must cover at least this area (in square degrees).
sun_cal.fBeamArea = 1
# The 3dB beamwidth of the sun must be at least this area (deg**2).
sun_cal.fBeam3dBArea = 0.200000003
# The peak power must be at least this, in SNR.
sun_cal.fBeamPowerThresh = 0
# Alert if the sun's position error is larger than this, in degrees.
sun_cal.fBeamPosThresh = 0.5
# Alert if the LDR offset error is larger than this, in dB.
sun_cal.fBeamLdrOffsetThresh = 0.200000003