Order Tray | Contact Us | Home | SIG Lists

[aprssig] The best resolution of position from APRS

Robert Bruninga bruninga at usna.edu
Wed Jan 4 16:37:02 UTC 2006


>>> archer at eskimo.com 01/04/06 2:24 AM >>>
>> >I find this deprecation of compressed objects/items 
>> >unacceptable.
>> 
>> Stalemate.  I find the continued use of compressed
>> opject/items unacceptible as it leaves 10,000
>> APRS users unable to see them.
>
>How could I reach 10,000 Kenwood users:
>*) If APRS is supposed to be a local tactical network?

I assume your software is used around the world.
APRS is around the world.  Everywhere that your
software is used with the depricated object format
it will affect all surrounding kenwoods.

>*) If none of those Kenwood radios are linked to the internet?

APRS is an on-air portocol.  It was designed to
display EVERYTHING on the APRS channel.
If XASTIR is transmnitting the depricated object
format, it is denying those kenwood users the
ability to see what is around them.

>*) If most of the ones that _could_ receive the 
>packets are too busy driving to look at their display?

In a any kind of come-as-you are event, or SAR,
your radio has to be avaiable to be your resource.
If it cannot be used effectively because the
person putting out SAR objects is using XASTIR and
the compressed object format, then you and
your resource are excluded from seeing the
big picture.

>The way I figure it, I might affect 3 or 4 Kenwood 
>users at any given time during a SAR operation, 
>none of which are actually involved in SAR.  

That is the most shortsighted way to look at 
emergency communications preparedness that
I have ever heard.

In our area, about eveyone that shows up to do
anything with APRS shows up with a kenwood.
It sure is a lot more flexible, available and 
immediately ready than someone who shows up
with a PC, a TNC and a radio and a bunch of cables
and powersupplies.   The rule in communications
effectiveness is simplicity.

>> Then use the APRS1.2  !DAO! format which gives 
>> a resolution to under a foot AND includes the DATUM.
>> AND is 100% compatible with everything on the air.

>100% compatible as in almost nothing will see the 
>proper position, 

Which is better?  THe 1 foot proper position on
all current software and NOTHING AT ALL ON 
10,000 APRS MOBILES?

>but almost all with see a poorly-placed position for 
>that object. 

Yes, but they can UPGRADE by downloading new
versions of all software so they CAN see that
precision.  

>Sometimes that's worse than not seeing the object at all.

Then they should download their latest favorite
APRS program that supports the new100% backwrds
compatible !DAO! format.

It seems to me that XASTIR is what is holding us back
in refusing to support the 100% backwards compatible
!DAO! format,  not the kenwoods...

>> I cannot see any way to encourage such incompatibilities
>> in APRS  when doing so [continuing with the XASTIR use
>> of the obsolete compresse object format] would guarantee 
>> on-air confusion and missed information.

>Little on-air confusion I would suspect.  Can't be 
>confused about it if you don't know it's even there.  

A Mobile responding to a SAR or any other event that
cannot see the objects is a REAL CONFUSING ISSUE
if you ask me...

>I'll give you that, but as I iterated earlier it doesn't 
>matter much to my county's SAR units, as we're 
>not running Kenwoods. 

I you will limit distribution of XASTIR and make it so
that it cannot under any circumstances be used
anywhere else in the world except your local SAR
group, then I would agree.  But I thought XASTIR
was used in other places besides your local SAR group?

de WB4APR





More information about the aprssig mailing list