Using NWS County shapefiles for other packets


Fred Hillhouse
 

Greetings,

 

This is cross –posted to APRSSIG but the list appears to have been replaced by a forum. It is also on the Facebook APRS page.

 

Is there a mechanism to use the shapefiles that encompass counties for anything other than an NWS packet?

Here is an example that will display a FLOOD symbol inside two counties along with county outlines

PAHFLS>APRS,TCPIP,qAO,WE7U-WX::NWS_ADVIS:070730z,FLOOD,INC129-KYC225 {6H50l

 

After studying the details and documents for this packet (Thanks WE7U!), I am curious if other data could be displayed.

 

Is the packet type generic enough?

Can “NWS_ADVIS” be anything else?

I am not sure what determines the FLOOD symbol. Is it the product code of “FLS” or “FLOOD”?

 

A current scenario might be COVID-19 cases in a county, but that is only one example.

 

Just thinking about current world events and APRS.

 

I know the NWS is US based. Are other shapefiles available for counties, states, provinces, etc.?

 

I hope everyone is being careful and rides out this storm successfully!

 

Best regards,

Fred N7FMH

 

PS. The New York Times maps and data (free subscription for COVID-19)

https://www.nytimes.com/interactive/2020/world/coronavirus-maps.html

https://github.com/nytimes/covid-19-data

 

PPS. Is the APRSSIG email list really replaced by a forum? L

 




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Lynn Deffenbaugh
 

Actually, I would recommend looking into using the NWS MultiLine format for this purpose.  It requires nothing to be installed except an APRS client that supports this display.  You can't transmit the same level of detail as a local shapefile selection can deliver, but you also don't need to have shapefiles installed to see the described area.  Another advantage is that the base packet still supports location, symbol, and comment text, unlike the shapefile selection stuff.

This is what KJ4ERJ-15 uses to put the footprint circles around the ISS and PSAT* satellite objects.


As for where the flood symbol comes from, it is the "product code" that is "FLS" for "Flood Statement" in your example packet.  The "source" callsign is the NWS office (or zone) and product code concatenated together.  In ARPSISCE/32, I went through all of the product codes and selected symbols for them for display.


The MultiLine format is generated for weather alerts as well and is what carries the non-shape shapes that are actually drawn by the weather forecasters themselves when alerts are issued.

And yes, this originated in the USA, but the Australians are doing their own thing.  The base pages for this information is (although the Australian page didn't come up when I just tried it):



I'd have to go check the source code to see what the conditions are that trigger the shapefile lookup, but I know the multiline is simply the presense of the proper }xxxxxx{seq# at the end of a packet.  Here's a few samples from the satellite objects:

KJ4ERJ-15>APZTLE,TCPIP*,qAC,NINTH:;ISS      *234348h4637.47N\09311.67WSMsg4Pass }k1mkNbrQzAq5a1N5;A+Q#b*kN{!wJU!
KJ4ERJ-15>APZTLE,TCPIP*,qAC,NINTH:;PSAT     *234355h3709.89N\10424.05ESMsg4Pass }k1kpNhnTz@t1c,N19@(T"h.pN{!w0'!
KJ4ERJ-15>APZTLE,TCPIP*,qAC,NINTH:;PSAT2    *234424h2649.97S\13728.36WSMsg4Pass }k1iuNne\vEz0l'N00E#\&n7uN{!wm<!
And lots more at https://aprs.fi/?c=raw&call=KJ4ERJ-15 (but aprs.fi thinks the satellites fly too fast!)

Oh, and the !xxx! as the "sequence" was specifically chosen to make it different than an NWS multiline which will always have a letter or digit as the first character after the {.

Lynn (D) - KJ4ERJ - Author of APRSISCE for Windows Mobile and Win32

On 4/7/2020 7:13 PM, Fred Hillhouse wrote:

Greetings,

 

This is cross –posted to APRSSIG but the list appears to have been replaced by a forum. It is also on the Facebook APRS page.

 

Is there a mechanism to use the shapefiles that encompass counties for anything other than an NWS packet?

Here is an example that will display a FLOOD symbol inside two counties along with county outlines

PAHFLS>APRS,TCPIP,qAO,WE7U-WX::NWS_ADVIS:070730z,FLOOD,INC129-KYC225 {6H50l

 

After studying the details and documents for this packet (Thanks WE7U!), I am curious if other data could be displayed.

 

Is the packet type generic enough?

Can “NWS_ADVIS” be anything else?

I am not sure what determines the FLOOD symbol. Is it the product code of “FLS” or “FLOOD”?

 

A current scenario might be COVID-19 cases in a county, but that is only one example.

 

Just thinking about current world events and APRS.

 

I know the NWS is US based. Are other shapefiles available for counties, states, provinces, etc.?

 

I hope everyone is being careful and rides out this storm successfully!

 

Best regards,

Fred N7FMH

 

PS. The New York Times maps and data (free subscription for COVID-19)

https://www.nytimes.com/interactive/2020/world/coronavirus-maps.html

https://github.com/nytimes/covid-19-data

 

PPS. Is the APRSSIG email list really replaced by a forum? L

 




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Lynn Deffenbaugh
 

And I completely forgot about the following which should let you play with MultiLines.

Multiline Creation in APRSISCE/32

APRSISCE/32 now has a rudimentary multiline object creation capability built in. Follow the procedure below to create your own tracked objects and convert them to a MultiLine object.

  1. Right click at one end of your line or one point on your area. From the Coordinate cascade, select "Create Object HERE" and give it a name and comment. You'll need to keep it Enabled, but you do not need to check any of the Vias. The screen should center and lock on your new object.
  2. Drag and pan to the next point along your line or area. Again, right click, but this time select "Move <ObjName> HERE" from the coordinates cascade.
  3. Repeat step 2 as many times as necessary to build up the line or area boundary using the tracks you're making with the object. I don't enforce the 23 limit yet, so please don't say it's broken if it breaks.
  4. If you don't like the most recent point you added, you can left (normal) click on the object itself and select "Shrink Track" from the new "My Object" cascade. After confirming, the object track will have the most recent point removed.
  5. When you have all of the line segments tracked, or are one step from closing your area, left (normal) click on the object name itself. From the new "My Object" cascade, select "Track to Area" or "Track to MultiLine".

When APRSISCE/32 creates the Multiline object, it takes into account the distance to the most distant offset, and uses that to determine the scale required, and then attempts to find the best fit for each vertex defined.

Now you can compare your object's track with the line or area boundary that you got. Expect LOTS of error depending on the size of your
maximum offset. Also, since MultiLine objects are relative the object position, don't be surprised to see the line or shape move intact if you
decide to start over with the same object!

From http://aprsisce.wikidot.com/doc:multiline

Lynn (D) - KJ4ERJ - Author of APRSISCE for Windows Mobile and Win32

On 4/7/2020 7:13 PM, Fred Hillhouse wrote:

Greetings,

 

This is cross –posted to APRSSIG but the list appears to have been replaced by a forum. It is also on the Facebook APRS page.

 

Is there a mechanism to use the shapefiles that encompass counties for anything other than an NWS packet?

Here is an example that will display a FLOOD symbol inside two counties along with county outlines

PAHFLS>APRS,TCPIP,qAO,WE7U-WX::NWS_ADVIS:070730z,FLOOD,INC129-KYC225 {6H50l

 

After studying the details and documents for this packet (Thanks WE7U!), I am curious if other data could be displayed.

 

Is the packet type generic enough?

Can “NWS_ADVIS” be anything else?

I am not sure what determines the FLOOD symbol. Is it the product code of “FLS” or “FLOOD”?

 

A current scenario might be COVID-19 cases in a county, but that is only one example.

 

Just thinking about current world events and APRS.

 

I know the NWS is US based. Are other shapefiles available for counties, states, provinces, etc.?

 

I hope everyone is being careful and rides out this storm successfully!

 

Best regards,

Fred N7FMH

 

PS. The New York Times maps and data (free subscription for COVID-19)

https://www.nytimes.com/interactive/2020/world/coronavirus-maps.html

https://github.com/nytimes/covid-19-data

 

PPS. Is the APRSSIG email list really replaced by a forum? L

 




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Jon KM8V
 

Is there a document or guide on how to gate NWS warnings and watches out over the air?

I'm not sure how to subscribe to or receive warning or alert info from the WXSVR.

Thanks & 73 de KM8V