altimeter netCDF file

How do I...?
User avatar
hproe
Posts: 504
Joined: Sat Nov 27, 2010 3:46 pm

altimeter netCDF file

Post by hproe »

Hi -

I have altimeter data in netCDF format. Loading it with data type 'netCDF/GEMPAK Point Data files' the parameters are listed correctly in the Fields tab as 'Gridded Fields' and 'Point Data'. Using 'Point Data' and display type 'Point Data Plot' I can display the satellite track when selecting 'multiple' in the 'Times' tab in the Layer Controls. However, when I select one of the 'Gridded Fields' the display type 'Point Data Plot' is not available, and none of the listed display types fits the line data. Sample file attached.

cheers, HP
Attachments
nrt_global_al_phy_vfec_l3_20180524_20180612.nc
(574.48 KiB) Downloaded 292 times
User avatar
jayh
Posts: 424
Joined: Thu Jan 15, 2009 10:34 pm

Re: altimeter netCDF file

Post by jayh »

Hi HP-

I wanted to give a quick update on this. I do see the same problems you are seeing with your netCDF file. I haven't been able to find a way to get the Point Data Plot for the gridded fields. I have sent this to the programmers and am awaiting a reply. I'll update this thread when I get some more information. Thanks for your patience.

Thanks, Jay
User avatar
bobc
Posts: 988
Joined: Mon Nov 15, 2010 5:57 pm

Re: altimeter netCDF file

Post by bobc »

Hi HP,

The Point Data Plot display type will not work with gridded fields. A comparable gridded display you can use is Value Plots. In order to use the gridded display types in McIDAS-V with this data, you'll have to adjust the Time Binning settings. If you choose the Point Data field, the Point Data Plot display type, and hit Create Display, you'll notice a message that there are 22,427 timesteps included with the data. Each one of these timesteps likely don't include enough observations for McIDAS-V to do a contour analysis. This is where Time Binning comes in, where you can group all of these data points into 1 timestep. To do this, do the following:

  1. Once you have your data in the Field Selector, double-click on "nrt_global_al_phy*" under Data Sources in the left panel of the tab. This opens the Properties window for the data source.
  2. At the bottom of the Properties tab of the Properties window, you'll see a section for Time Binning. I set "Bin Size" to "1 day" and "Round To" to "1 hour". Hit OK in the Properties window.

At this point, all of the data (a day's worth) will be grouped together into one timestep and the gridded display types (including Value Plots under Plan Views) should work.

Please let me know if this doesn't work or if you have any further questions.

Thanks,
Bob Carp
User avatar
hproe
Posts: 504
Joined: Sat Nov 27, 2010 3:46 pm

Re: altimeter netCDF file

Post by hproe »

Hi Bob -

Many thanks for the tip - should have recalled the binning! Maybe, the User's Guide on this topic could be improved a bit. E.g. one could mention, reference to the binning under 'Point Data Plot Comtrols'.

Now to the displays. Value display does not produce one at all. Contour-shaded/filled produce tracks with big footprints, where you get lost somehow, like in the attached figure.

Any idea how to proceed?

thanks, HP
Attachments
contourFilled.png
User avatar
bobc
Posts: 988
Joined: Mon Nov 15, 2010 5:57 pm

Re: altimeter netCDF file

Post by bobc »

Hi HP,

I'm having some difficulty replicating your problems. Here is what I did (numbers 1 and 2 are the same from my previous post):

  1. Once you have your data in the Field Selector, double-click on "nrt_global_al_phy*" under Data Sources in the left panel of the tab. This opens the Properties window for the data source.
  2. At the bottom of the Properties tab of the Properties window, you'll see a section for Time Binning. I set "Bin Size" to "1 day" and "Round To" to "1 hour". Hit OK in the Properties window.
  3. Choose the "Gridded Fields > adt_filtered" field, the "Plan Views > Color-Filled Contour Plan View" display type, and hit Create Display.
  4. From the Main Display window, change the enhancement to "System > Gray Scale".
  5. From the Field Selector, choose the "Gridded Fields > Value Plots" display type, and hit Create Display.
  6. Not necessary, but I modified the "Grid Value" Layout Model to remove the plus sign at the location of the data point and I changed the number value format to give 3 decimal places instead of 1.

This gave the following image in both today's nightly as well as the last release, 1.7u1:
adt_filtered.png

Are you doing anything different to create your display? For example, did you use any formulas or adjust anything in the Grid Parameters subset tab of the Field Selector before creating the displays? When you say "Value display does not produce one at all", are there any error messages? Our Color-Filled Contour Plan View displays are actually similar. I think the main difference is my display background is white, so areas where no data exists (e.g. over land and between swaths over the ocean) are white. I'm guessing your display background is gray, making the areas with missing data gray and causing it to blend in a bit with the actual gray-scale data.

Thanks,
Bob
User avatar
hproe
Posts: 504
Joined: Sat Nov 27, 2010 3:46 pm

Re: altimeter netCDF file

Post by hproe »

Hi Bob -

Yes, we get the same colour-filled display, just with differing backgrounds. My issue is however, the generous width of the adt track. I would expect a somewhat slimmer track that hardly overlaps with the landmass.

As regards the value plot, I tried the type 'Plan Views > Value Plots' and, as already said, it does not produce something - no layer and no error message. I see that you use 'Gridded Fields > Value Plots', but I cannot see the display type 'Grdded Fields' in my installation.

HP
User avatar
bobc
Posts: 988
Joined: Mon Nov 15, 2010 5:57 pm

Re: altimeter netCDF file

Post by bobc »

Hi HP,

Sorry for the typo, I meant to say that I was using the "Plan Views > Value Plots" display type. Could you please set your log level to TRACE through the Advanced tab of the User Preferences, try displaying your Value Plots, and send us your mcidasv.log file? Perhaps an error or warning message is going there. Another possibility is that the layout model being used for your Value Plots display isn't correct. From the Layer Controls, this should default to using "Grids>Grid Value":
adt_filtered_layoutModel.png

To make sure that your Layout Model is displaying the data for the field you selected, do the following:
  1. From the Layer Controls, click the double-down blue arrow next to the Layout Model and click Edit (red number 1 in image above).
  2. From the Layout Model Editor, you should have a "123" shape included in the layout model (red number 2 in image above). Double-click on this "123" shape to get to the Properties window of the shape.
  3. From the Properties window, make sure you have a "*" listed in the Parameter field (red number 3 in image above). I'm wondering if you've edited this at some point to hard-code in a specific parameter that you aren't currently displaying. A "*" in this Parameter field acts as a wildcard and will use whatever field you selected at Create Display.

If this doesn't help, getting some screenshots of the Layer Controls of your Value Plots display and the Layout Model Editor (similar to my image above) would be helpful.

As for the width of the data, you can narrow it by adjusting some of the items in the Grid Parameters subset tab of the Field Selector. For example, I changed my Search Radius from 10 to 1 and got a much narrower track:
adt_filtered_searchRadius.png

You can find more information about the items in the Grid Parameters tab on the Gridded Point Data page of the User's Guide. Note that you'll have to uncheck the "Use Default" checkbox in the Grid Parameters tab to allow you to edit these settings. This Search Radius can be set to a decimal value as well. For example, a value of 0.2 makes the swath even narrower.

Bob
User avatar
hproe
Posts: 504
Joined: Sat Nov 27, 2010 3:46 pm

Re: altimeter netCDF file

Post by hproe »

Hi Bob -
Now I am completely lost. I cannot even display adt in display types that worked before - no layer and display for whatever display type. I also tried 1.7u1 to no avail. Find attached the log file.
HP
Attachments
mcidasv.log
(108.61 KiB) Downloaded 282 times
User avatar
bobc
Posts: 988
Joined: Mon Nov 15, 2010 5:57 pm

Re: altimeter netCDF file

Post by bobc »

Hi HP,

Are you able to create a simple Image Display of satellite data? If not, can you please send us your mcidasv.log file as soon as you click Create Display?

Did you make any other changes to your User Preferences when changing your logging level to TRACE? It could be worth trying to change your log level back to the default level of INFO and see if this makes an improvement.

To verify that nothing is wrong with your actual machine, can you try starting up McIDAS-V from the command line with the -tempuserpath flag? For example, from your McIDAS-V-System directory, run: runMcV.bat -tempuserpath

This will start McIDAS-V as if it were the first time run on your machine. Are you able to create your displays when running McIDAS-V this way?

Thanks,
Bob
User avatar
bobc
Posts: 988
Joined: Mon Nov 15, 2010 5:57 pm

Re: altimeter netCDF file

Post by bobc »

Hi HP,

Another question we thought of is if you are running McIDAS-V off a flash drive, like we believe you do for training. If that's the case, then it's possible that disk space with the log files could be giving some issues. With your logging back at INFO, you can look in your /McIDAS-V/archived_logs/ directory and you should see 9 or 10 log files in there. It's possible that with TRACE logging some of these files could be pretty large. You could try deleting them and see if it helps things.

Thanks,
Bob
Post Reply