[aprssig] Satellite positions: FREQUENCY

Lynn W. Deffenbaugh (Mr) ldeffenb at homeside.to
Wed Oct 19 06:23:23 CDT 2011

On 10/19/2011 2:16 AM, Greg Dolkas wrote:
> Adding my $.02...
> YES to what Bob describes here, especially the idea of using the DX 
> Cluster format for future passes.  Those slots have yet to have 
> anything drop into them in the many years I have owned my D7, and this 
> is a great use.

Sorry, not happening.  The ONLY thing an APRS-IS server can push through 
IGates to remote RF users is an APRS message.  And the only way I'll 
know there's one out there is to respond to an APRS message query.  
There's a method to (at least some of) my (seeming) madness.

> Anything more than an hour away will have to get converted to a 
> specific time anyway, and written down, otherwise it will get 
> forgotten or mis-remembered. 

Then just query again when you think you've got the time.  Remember, 
this is for CASUAL satellite pursuit. (3 hours from now, I'll not be 
anywhere near the radio).  If you mis-remember a future pass time, oh 
well.  If you happen to recall it later (didn't that say somewhere 
around NOW), send another query.

> I'm not sure how it would fit, but knowing the date as well as the 
> time would be good, given that a suggested near-GEO satellite could 
> have passes lasting more than a day, and not repeating for more than a 
> day. 

Delta times remain short.  They reference NOW and the whole service is 
intended to be immediate, not future.  Why do people text so much?  They 
like the immediate feedback.  Yes, serious satellite workers plan hours 
(days?  weeks?) into the future to catch that "perfect" pass.  This 
isn't intended for them.  It's intended for quick pertinent information 
for NOW and hints into the future.

> Hmmm, LOS in 507min is kind of meaningless too.  Maybe LOS in 8h27m if 
> it's longer than an hour away?

Expect the delta time format to transform when I have a moment (or maybe 
6m29s) available.   That's a suggestion I can agree with.

> Don't forget about the max elevation for the pass. 

It's already there.  You haven't queried recently, have you?

> ...especially if the Az of that max elevation is also given.  "10 
> degree pass behind that big hill over there to the East..."  Yeah, 
> skip it.

Considering the azimuth along with the MaxEl for future passes and 
possibly a heading (4 or 8 compass points in characters) within a pass.  
I'm finally hearing the INFORMATION that would be useful instead of 

> I like the idea of asking what satellites are coming up next, but 
> prefer that to be the default if the message is empty.  Otherwise, the 
> message would have a command and a satellite name, say "PASS 
> satellite, satellite...", leaving open other commands, perhaps for 
> MODE, FREQ, or other things that can be predicted based on the 
> satellite, time of day, and your location.

Non-satellite-directed queries (SATS or SATSRV) are further out in the 
future, maybe 7d13h or so... (but that's just a delta estimate).

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

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