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How to display weather data onto a sphere

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 so im in delphi 10.4 CE and im trying to make a weather application and i woud like to view NEXRAD/satellite/vector data on to a sphere with a bitmap image of the earth but im not sure

on how to lay1er the data on to the sphere APP uiusing netcdf here is a picture of the application with the globe 

Edited by Linuxuser1234

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The data must have location info in some kind of polar coordinates, so you can translate them onto the flat bitmap that you use on your sphere.

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48 minutes ago, Linuxuser1234 said:

@Doug Rudd the data i get is from thredds so i dont know how to even convert the data to be visualized in delphi and nobody from unidata knows either 

But the data format is known/documented? There must be some kind of coordinates in there, probably in WGS84.

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3 hours ago, Linuxuser1234 said:

@dummzeuch also do you know how i can plot wind vectors like this 

Screenshot 2022-10-02 111333.png

No idea. I'd assume that the data contains the information for doing this, but it will be up to you to draw the actual graphics. So basically the process is:

  1. read a data point from the data
  2. convert the coordinates from whatever coordinate system it uses to the one you need for drawing
  3. draw a circle + an arrow in the right direction and length + the number

I can't really help you there any more because I neither know the data format nor have I ever drawn a map on a sphere.

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13 hours ago, Linuxuser1234 said:

do you know how to display this popup form i made when i click on the goes button 

That is basic stuff, perhaps you should consider a Delphi course or reading a book.

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I don't know what data you are trying to plot, but wind data from the NWS or other sources are in two formats:   direction/speed      or     north component of speed/east component of speed.    Gridded data is usually in the latter format.     In the direction/speed format, the direction is that FROM which the wind is blowing.   That is a reported 315/21   means that if you face towards the Northwest, the wind will hit you in the face, so your plotted vector would be to the southeast (or if you are using the meteorologists' wind barb depiction, the "arrow" would be coming from the NW.)     But I would, in your code, first align your wind indicator to your geographical location.  That is make your arrow, say 10 miles long if that fits your scale; then taking the lat/long of the location, figure the lat/long you would be at if you went with the wind 10 miles and figure that lat/long.  Save all these wind arrow start and end point pairs.  And when it comes time to convert your background map to the projection on the flat screen of the display, fold in the wind data using the same equations.   Step by step it sounds lengthy, but computers are fast.


Good luck.


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