[aprssig] Re: TIGER maps what-s the problem?

Wes Johnston wes at kd4rdb.com
Tue Jun 13 15:07:17 EDT 2006


Yes, that's the reason.... the kenwood radios won't support base91 objects. 
In all fairness, I've been meaning to add the option for Base91 to my little 
perl script, but I kinda figured "what's the point".

I did write !DAO! support into the perl script (WGS 84 with machine readable 
AO).  The only thing I know to do at this point (trying to send postions 
better than 60' to two devices with differing capabilities) is to use the 
xastir_udp_client program twice for each object... send DAO to the RF 
interface Base91 to the NET interface... in that order so that xastir sees 
the bestest position last.  In other words, an object would jump over to the 
60' spot for just a moment, and as soon as I sent Base91 the object would 
jump to the 2' spot.

But there's no guarantee of that.  If I send a DAO copy of a packet out on 
RF and follow it up a fraction of a second later with a Base91 on the 
network interface..... the DAO could bounce around the digipeaters for 5 to 
10 seconds and the DAO copy will come back into xastir after I sent the 
Base91 position.  This will cause xastir to use the latest position it heard 
which is the 60' postion.  It defeats my attempts.

I am very frustrated that the kenwood radios won't support Base91 objects, 
but what can we do execpt beat up on the thing that we _can_ change!! ;-) 
Curt you really should commit xastir to ROM so we have to work the spec 
around the "would be static" xastir!!

I suppose another option would be to truncate the names of the rino radios 
to 6 characters and send them as regular aprs Base91 compressed position 
reports.  But then that starts to get into legal issues b/c the names look 
like callsigns and we have to ID them as tactical callsigns.  The kenwoods 
will decode aprs stations using compressed postion reports right?

Wes


----- Original Message ----- 
From: "Curt, WE7U" <archer at eskimo.com>
To: "Wes Johnston" <wes at kd4rdb.com>
Cc: "TAPR APRS Mailing List" <aprssig at lists.tapr.org>
Sent: Tuesday, June 13, 2006 12:55 PM
Subject: Re: [aprssig] Re: TIGER maps what-s the problem?


> On Tue, 13 Jun 2006, Wes Johnston wrote:
>
>> Actually, the 60' limit of a standard aprs position is killing me with 
>> the
>> rino radios.  It's very difficult to explain to the layperson looking at 
>> a
>> photo of an event why all there is only one icon showing near the trailer
>> we're using.
>
> Explain to me again why you're not using base-91 compressed
> positions?  Is it because Kenwoods understand base-91 stations, but
> not base-91 objects?
>
> If you _could_ use base-91, you'd have separate icons as you zoomed
> in, at their correct positions and within 2 or 3 feet of the true
> location if the GPS was capable of it (which it is not, but it's
> capable of better than 60').
>
> --
> Curt, WE7U.   APRS Client Comparisons: http://www.eskimo.com/~archer
> "Lotto:    A tax on people who are bad at math." -- unknown
> "Windows:  Microsoft's tax on computer illiterates." -- WE7U
> "The world DOES revolve around me:  I picked the coordinate system!"
> 






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