Dynamic LST Validation (NEW!)
We have added a new tab to the scheduling block (SB), "Dynamic LST Validation" (aka Block Checker Tool). This new built-in tool will allow observers to check their observations for a specified LST start range and several defined parameters.
Important Notes:
This new tool is a work in progress. Please contact the NRAO Science Helpdesk if you encounter any issues, discrepancies, or you see a message with "unknown" severity.
The NRAO staff will continue to check SBs before approving for observation.
We have added a few new parameters to help observers check their SBs:
- Antenna Shadowing (applicable to D and C-configuration)
- Observers may now enter an antenna shadow limit (in meters) to help them determine when during the LST start range antennas are being shadowed, which antennas are shadowed, and by how much (in meters).
- Antenna shadowing information remains present on the Static Reports tab in the Summary Report table near the bottom. You will need to adjust the assumed LST start time to check when/if there are shadowed antennas.
- Antenna Wraps (CW, CCW, or no preference)
- We have made this visible to observers to help determine which antenna wrap should be selected. However, we realize the output is not always correct and can be confusing. We are continuing our work to optimize this for less confusion. If you are confused, ask us for help in determining which antenna wrap to use if you are unsure.
- Basic tips for selecting an antenna wrap at the start of an SB:
- Select the CCW wrap, if the starting azimuth is ~70-90d.
- Select the CW wrap, if the starting azimuth is ~270-290d.
- No antenna wrap is needed if the starting azimuth and the sources following are:
- always in the north: azimuth is ~290-445d (outer wrap) or ~-85d-70d (inner wrap)
- always in the south: azimuth is ~90-270d
- Max Slew Time
- This check can help the observer determine when there are long antenna slews between sources, i.e., flux/bandpass cal and complex gain calibrator or if a group of science targets have long slews between them possibly indicating the scans in the SB may benefit from being rearranged or perhaps split out into a different SB.
- 4m 30s is the default setting. Observers may adjust the time to a maximum of 8m 0s.
- Syntax is important, must be in minutes and seconds, e.g., 4m 30s, 5m 5s, 2m (0s will be autofilled), etc..
Dynamic LST Validation Parameters
As seen in the screen capture of the Dynamic LST Validation tab within the OPT, please note the "?" found beside each parameter. While working in the OPT, the "?" can be found throughout and contain helpful information regarding the parameters.
Starting Conditions
The following are editable starting conditions.
LST Start Range | To use the same LST start range from the Information tab, select the "Get LST From Info Tab" button.
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LST Step |
This will allow you to step through the defined LST start range in increments of 5, 10, 15, 20, 25, or 30 minutes. The default is 5 minutes, since the LST start range can be set in 5 minute increments. |
Assumed Antenna Starting Direction |
Azimuth This will help you determine if you have enough slew and on source time for the first calibrator scan, i.e., reference pointing, flux, bandpass, complex gain calibrator, etc.. The default starting AZ position is 225.0d.
Elevation You may also set an assumed starting elevation position. The default starting position of 35.0d is usually sufficient. |
Evaluator Settings
The following are editable evaluator settings.
Antenna Shadowing |
Shadowing Limit (max)
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Elevation Limits |
Low EL Limits
High EL Limits
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Max Slew Time |
Time:
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Time On Source Minimum |
You may edit the recommended default settings for your observation. |
If you wish to reset the evaluators to the default settings, select "Reset to VLA Defaults". Note, the starting conditions will not be reset.
Running the Block Checker
Once you are satisfied with your starting conditions and evaluator settings, select "Start Dynamic LST Validation".
The results may be grouped by evaluator, severity, LST, or all.
A "Show All" or "Hide All" results option is also available.
This can be helpful when there are many messages and want to focus on a particular evaluator or severity. The messages in the table(s) may be sorted by selecting the top row of each column, i.e., by scan name, scan number, etc..
In addition to the editable evaluator parameters, you may see addition evaluator messages if they have been flagged in your SB. If they do not appear, then they were not used. This is likely ok. It is also ok if after you select "Start Dynamic LST Validation", you see the info message: "No Messages to display. Scheduling Block looks good."
Message Types
Evaluators
Setup Scan |
messages will appear if,
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Scan Time Type |
messages will appear if the prohibited time types are found:
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Flux Calibrator |
message will appear if 3C295 is used as the flux density scale calibrator.
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Scan Intent |
messages will appear if,
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Scan Flags |
Three types of warnings may appear under this evaluator: indicates a special mode for observing is in use and may not be what was intended. If intended, then it may be ignored.
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Scan Duration - Maximum |
will appear for all scans and all LST start times which exceed the default scan duration maximum of 15 minutes.
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Source Elevation - Maximum |
will appear for all scans and all LST start times which exceed the defined elevation maximum.
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Source Elevation - Minimum |
will appear for all scans and all LST start times which exceed the defined elevation minimum.
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Time On Source - Minimum |
will appear for all scans and all LST start times which exceed the defined time on source minimum set in the table.
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Antenna Wrap |
will appear when the incorrect antenna wrap has been selected.
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Max Slew Time |
will appear when the selected max slew check is exceeded.
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Antenna Shadowing |
will appear when the selected antenna shadowing max has been exceeded.
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