3. SPECTRUM MONITORING TASKS
3.1 Metrics - Task Calendar (Optional)
3.1.1 Entering Task Items
Task items include measurement setups, and measurement results. When you enter a Task, you always have the opportunity to give it an identifying name. Once entered, each item is placed into the Task Calendar and is viewed from the main Task Calendar screen.
Figure 3-1 Task Calendar Window
Table 3-1 Task Calendar Window Field/Button Item Descriptions
Field/Button Item Description
Hour Increment Bar (12a to 12a) This display bar shows Tasks that have been scheduled into a particular time slot. This is to display all Tasks the have been scheduled to run within the entire 24 hour period of the day. The marker color relates to the status of the Task performed.
*
HINT: Click on the Hour Increment Bar to scroll the 5-Minute Increments task list.5 Minute Increment Task list with Scroll Bar
This display region shows a limited amount of 5-minute intervals for scheduled measurements being performed. The user may scroll up or down to display any 5-minute period of the day.
Desired measurement Tasks are listed with the identification assigned to them and a colored box that displays the Tasks status.
Any stored Tasks can be reopened and modified. The Spectrum Monitoring system provides a quick way to delete, modify, or find a Task.
NOTE: Scheduled DF Measurements (calendared events) will only be displayed for the currently connected Server. Only one Server will be connected at any one time for Scheduled events.
Entries are made to the calendar by selecting the desired day/time and entering specific measurement requirements into the customization tabs and then clicking on <Schedule>, located on the "Measurement"
tab. The item entry tabs are discussed below in Table 3-2 through Table 3-9. Placing a check mark into the box displaying the type of customization desired gives the user access to the additional customization tabs.
In addition to listing the scheduled Task items, the Task software indicates the item status as follows:
Table 3-2 Scorpio Client Calendar Box Color Descriptions
Task Calendar Box Color Description
Blue “Task” is currently being sent to the Spectrum Processor.
Red “Task” Request has not been sent to; or “Task” Result
confirmation has not been received from the Spectrum Processor.
Green “Task” has been received and scheduled for completion by the Spectrum Processor.
Yellow “Task” should have been run but confirmation of Task Results has not yet been received from the Spectrum Processor.
Grey “Task” Results have been successfully retrieved from the Spectrum Processor and are available for examination.
Red check Mark “Task” is currently selected for viewing or editing.
Optionally, the Task Calendar is capable of identifying and displaying externally generated measurement results. As an example consider SHF measurements generated from an external Spectrum Analyzer, where the measurements are stored in files. These files can be loaded and viewed in an external measurement viewer.
An externally generated measurement result is given the label "EXT" to identify it as an external measurement. Each external measurement is numbered 1, 2, 3… in the Task Calendar, indicated with "-n"
that appears to the right of the "EXT." The filename used by the operator when saving this file appears in parenthesis to the right of the number identifier. For example, two external measurements may be labeled
"EXT-1 (filename1.bmp)" and "EXT-2 (filename2.gif)."
External measurement files placed in a subdirectory "External" will be located by the Scorpio software and will appear in the Task Calendar window based on the date/time of the saved file.
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3.1.1.1 Measurement
Central to each scheduled Task, are the measurements you perform to gather required information.
When you enter a scheduled Task, you must specify the following basic characteristics:
• Center frequency
• Bandwidth
• An identifying name
One or more of the following characteristics must be selected for measurement:
• Occupied bandwidth
• Modulation
• Field strength
• Frequency
• Direction
Figure 3-2 Scorpio Client Task Calendar Measurement Tab
Table 3-3 Scorpio Client Task Calendar Measurement Tab Field/Button Item Descriptions
Field/Button Item Description
Frequency Allows the user to enter the center frequency you want to measure in this field.
Bandwidth Allows the user to enter the necessary bandwidth for the modulation mode of the signal you want to measure in the Bandwidth field.
NOTE: Bandwidth values inconsistent with selected de-modulation mode will yield inaccurate results.
Identity Allows the user to enter a value for identifying the signal to be measured.
Antenna Allows the user to specify which antenna, from a list of available antennas, to be used for the metrics measurements. Note that the reference antenna is always used for the Direction measurements, regardless of antenna selection.
Table 3-3 Scorpio Client Task Calendar Measurement Tab Field/Button Item Descriptions
Field/Button Item Description
Station Name When in "On-line" mode, this shows the currently connected Measurement Server and cannot be changed. When in "Off-line" mode, all defined Measurement Servers are listed and can be selected. Any previously retrieved measurements can be reviewed.
Schedule (D) – Delayed
(I) – Immediate
The <Schedule> button allows you initiate the Task measurement to be scheduled and will contain all parameters that have been specified with the use of the additional tabs.
Clear Clears the entries in all tabs of the currently selected Task.
Remove Removes the currently selected Task from the schedule. If you inadvertently create an unnecessary Task, or if you no longer need the Task, you can easily delete it from the mission list.
Check Boxes:
These are toggle switches that allow the user to gain access or remove access to the additional entry tabs that are available. Placing a check mark into the box by clicking on it gives the user access to that entry tab.
3.1.1.2 Bandwidth
The "Bandwidth" measurement reported by the signal measurement helps you identify over-modulated signals and also helps you identify the type of signal you are monitoring. The measurement works for all signal types including AM, FM, SSB.
Bandwidth measures the occupied bandwidth of the signal. You can select the one of the following bandwidth analysis methods:
• Beta %dB - measures the occupied bandwidth using the β 99% method
• xdB - measures the occupied bandwidth using the x-dB method
• Averaging Method - provides options by which to average the measurement data
• Measurement Time – provided optional Dwell and Repeat times.
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Table 3-4 Scorpio Client Task Calendar Bandwidth Tab Field/Button Item Descriptions
Field/Button Item Description
Beta %dB Setup Checkbox Y (dB) Beta (%)
This method finds the bandwidth within which β% of the energy is contained. A typical value for β is 99% for this measurement Server to collect a block of data and calculate the power spectrum using FFT. It repeats the collection and FFT process using specified averaging method processing for a specified dwell time. Next it estimates the noise floor and zeros out all FFT bins that are less than Y dB above the noise. A typical value for Y is 6 dB.
xdB Setup Checkbox X1 (dB)
X2 (dB)
This method finds the frequency limits such that all spectrum components outside these limits are at least x dB below a 0-dB reference level. Since the occupied bandwidth is the value that is regulated (No. 147 of Radio Regulations), this method is not the preferred one. In order to obtain better agreement with the occupied bandwidth measurement, the values of x vary with modulation type and have been empirically determined.
Averaging Method:
Mean RMS Max Hold
Select on of the averaging methods to average the results from each measurement repetition. Selection of the Averaging Method in the Bandwidth Tab is independent of other choices of Averaging Method. For example: The user may set a “Mean” Averaging Method in Bandwidth, and an “RMS” Averaging Method in the Modulation Tab.
Measurement Time:
Dwell (ms) Repeat
Dwell sets the measurement duration in milliseconds. Repeat allows the user to specify how many times to repeat the measurement.
3.1.1.3 Modulation
The "Modulation" tab allows the user to set modulation characteristics of the signal in the selected modulation modes. The system is capable of measuring "Amplitude," "Frequency," and "Phase modulation."
Figure 3-4 Scorpio Client Task Calendar Modulation Tab
Table 3-5 Scorpio Client Task Calendar Modulation Tab Field/Button Item Descriptions
For AM signals, the modulation depth m is measured. This is defined as:
m = (Emax – Emin)/(2Ec) where Emax and Emin are the maximum and minimum amplitudes of the modulated signal and Ec is average amplitude of the signal.
For FM signals, the primary measurement is the frequency deviation.
For PM signals, the primary measurement is the phase deviation. This is measured similarly to the FM measurements.
Averaging Method:
Mean RMS Max Hold
Select one of the averaging methods to average the results from each measurement repetition. Selection of the Averaging Method in the
Modulation Tab is independent of other choices of Averaging Method. For example: The user may set a “Mean” Averaging Method in Bandwidth, and an “RMS” Averaging Method in the Modulation Tab.
Measurement Time:
Dwell Repeat
‘Dwell’ sets the measurement duration in milliseconds. “Repeat” allows the user to specify how many times to repeat the measurement.
3.1.1.4 Field Strength
"Field Strength" tab allows the user to measure the field strength of the signal. Field strength measurements provide detailed information to determine the adequacy of radio signal strength and the effectiveness of the transmission source. It measures field strength at a specific frequency. Each time the operation is executed, the Spectrum Monitoring system will measure the field strength of a specified signal. This is primarily utilized in mobile measurement applications. You can use field strength measurement to:
• Determine the adequacy of a radio signal strength and the effectiveness of the source transmitter
• Ensure compliance with the relevant radio regulations
• Measure spatial-distribution of field strength
• Measure variation of field strength due to shadowing and other loss mechanisms
• Determine the interference effects of a given intentional radio emission (electromagnetic compatibility)
• Measure propagation phenomena
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Table 3-6 Scorpio Client Task Calendar Field Strength Tab Field/Button Item Descriptions
Field/Button Item Description
Specifies the type of detector used during field strength measurements.
Averaging Method:
Mean RMS Max Hold
Select one of the averaging methods to average the results from each measurement repetition. Selection of the “Averaging Method”
in the “Field Strength” tab is independent of other choices of
“Averaging Method.” For example: The user may set a “Mean”
“Averaging Method” in “Bandwidth” and an “RMS” “Averaging Method” in the “Modulation Tab.”
Measurement Time:
Dwell Repeat
Dwell sets the measurement duration in milliseconds. Repeat allows the user to specify how many times to repeat the measurement.
3.1.1.5 Frequency
The "Frequency" tab allows the user to measure the center frequency of the signal.
Figure 3-6 Scorpio Client Task Calendar Frequency Tab
Table 3-7 Scorpio Client Task Calendar Frequency Tab Field/Button Item Descriptions
Field/Button Item Description
Frequency Measurement Method:
Instantaneous Frequency
Method used to measure frequency.
Averaging Method Mean
RMS Max Hold
Select one of the averaging methods to average the results from each measurement repetition. Selection of the “Averaging Method”
in the “Frequency Tab” is independent of other choices of
“Averaging Method.” For example: The user may set a “Mean”
“Averaging Method” in “Bandwidth” and an “RMS” “Averaging Method” in the “Modulation Tab.”
Measurement Time:
Dwell Repeat
“Dwell” sets the measurement duration in milliseconds. “Repeat”
allows the user to specify how many times to repeat the measurement.
3.1.1.6 Direction
The "Direction" tab allows the user to specify or alter existing DF entries. When performing DF, the user may specify a confidence value for the signal of interest being tasked. This window also allows the user to specify a bandwidth to be used if it varies from that used in the "Measurement" tab.
Figure 3-7 Scorpio Client Task Calendar Direction Tab
Table 3-8 Scorpio Client Task Calendar Direction Tab Field/Button Item Descriptions
Field/Button Item Description
Confidence The Confidence factor (CF) allows the user to set a confidence value in percent. Confidence ranges from 1 to 99, with 99 being high confidence. A typical value for confidence is 80*.
Bandwidth Bandwidth allows the user to enter the necessary bandwidth for the modulation mode of the signal you want to measure in the Bandwidth field.
Polarization (optional) Polarization allows the user to perform the measurement(s) using the vertical or horizontal components of the antenna, if available.
Use this Bandwidth (not Measurement BW)
Check this box to specify whether to use the Bandwidth entered into the Measurement Tab or the Bandwidth entered above.
Measurement Duration Dwell
Cuts
Dwell sets the measurement duration in milliseconds. Cuts allow the user to specify how many times to repeat the measurement.
NOTE: Server software will finish the DF measurement when either of those two parameters reaches specified value.
*Note: The confidence number returned from the measurement is based on how well the amplitude and phase from each antenna matches the computed answer. A perfect agreement will return a confidence of 99. Due to multipath propagation, it is difficult to always have perfect agreement. A confidence of 80 will provide a useable DF.
3.1.1.7 Tasking Options
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Figure 3-8 Scorpio Client Task Calendar Tasking Options Tab
Table 3-9 Scorpio Client Task Calendar Tasking Options Tab Field/Button Item Descriptions
Field/Button Item Description
Tasking Selection:
Immediate Delayed
Select when you want the measurement to begin in the Start field.
You can select:
• Immediate - to start the measurement at the present time.
• Delayed - to start the measurement at a later time Delayed Scheduling Options:
If you select Delayed: You can specify the Task to be run when it is convenient for the Scorpio Server to run it. If a measurement must be made at a certain time, then the Rigid button should be chosen to confirm that the measurement time should not be varied upon. The user can also specify whether or not this measurement should be repeated.
Repeat Options Task Count Period
If the user has chosen that this Task be repeated, a Task count must be specified. Period defines the interval between repetitions.