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[aprssig] APRS as a Situational Awareness tool

Keith VE7GDH ve7gdh at rac.ca
Tue Jan 15 03:55:26 UTC 2008


Bob WB4APR wrote...

> I think ANY APRS program or clone can pretty well be used as the
> map display.  And just about anyone in the club can use those
> functions. That has rarely been a problem since that seems to be
> the focus of most clones.

If they are operating in a Windows environment, you might as well recommend
that they use the best APRS client going... UI-View32 ver 2.03.
www.ui-view.org

> You will notice that almost all of my complaining over these
> years rarely has to do with displays, but instead is the lack of
> any care for the optimal -transmission- of data keeping in
> mind the limitations of the network and human nature which can
> not be relied on for real-time settings in each changing
> situation.

I'm sure glad that UI-View knows how to beacon at a variable rate when it's
moving (i.e. GPS attached and enabled) and at a fixed rate while not moving.
It isn't quite SmartBeaconing, but it can beacon at a fixed rate (no GPS), at
a variable rate (GPS enabled) either every X miles or km, or every X minutes.
It could be set for every 10 minutes and every 1 or 2 or 3 km or whatever
depending on circumstances, and of course at a separate rate via TCPIP if you
have an Internet connection.

> Too many clones simply focused on the maps, and just figured
> transmit at a fixed rate and they were done. Extremely simple,
> but not at-all what APRS transmission was all about as a SYSTEM
> and a network.

I must be incredibly lucky... or lazy. UI-View was the first APRS client I
tried. Roger has been a silent key for nearly 3 1/2 years and nothing on the
horizon seems ready to replace it. Of course, that's partly because it doesn't
just focus on maps (although it's pretty good in that department), or just
beacon at a fixed rate, and not do all of the other things that can be done
with APRS.

> Many of the following parts of the TRANSMIT algorithms were left
> out of many clones making APRS hard to use in real time:
>
> - High initial rate (8 seconds) for any new data
> - Continuous decay  (doubling of time to next pkt)
> - 10m final rate if path is direct or one hop
> - 30m final rate if path is 2 or more hops

No, UI-View doesn't do the above. However, most UI-View installations are
fixed and not mobile. Some people, myself have gone mobile with it. It
certainly gives you the big picture of everything that's going on around you
as well as allowing you to watch for messages and bulletins, view WX stations
and other WX related alerts and so on. It also makes a dandy fully traceable
new WIDEn-N digi and can also respond to SSn-N. It also happens to make a
dandy IGate.

> - Decay applies to GPS input too (parked cars)

It doesn't have a decay rate, but it is more than capable of beaconing every X
minutes or every X km (or miles), so essentially it will beacon at one rate
with a GPS connected plus every X km. Disable the GPS and it can beacon at a
much slower fixed rate. Not too many people go mobile with it, but I and
others have.

> - Decay also applies to OBJECTS, WX and own station

Nope... doesn't do that. It beacons objects at the "object interval" setting.
The WX station setup has its own beacon rate. The station beacon rate is
described above.

> - Smart (redundant and delayed) acks for messages

UI-View handles messages very well. You can set the retry interval, the number
of times to try, and have it retry if the destination station is heard again -
if you didn't have an expire timer set on the message. It can display all
messages, just yours, bulletins, NWS bulletins and you can also set up your
own message groups. It keeps track of how many characters you have entered
while composing a message and has a setting for messages going to a D7. You
can enter 67 characters or 45 characters with the D7 setting.

> - embedded reply-acks to greatly improve message throughput

I don't know what embedded reply-acks are.

> - proportional pathing (lower rate for higher hops)

Doesn't have that.

> - Message delivery time out -and- RETRY-ON HEARD

As mentioned above, does a very good job with retry on heard.

> - ALOHA circle automatically computed & displayed
> - Aloha circle determines max hop count

Yes, but a readily-available add-on is required.

> - Warnings against improper settings

Perhaps you could ask Roger to add this next time you see him.

> - Transmitting PHG data so we can SEE the RF network

PHG goes in the beacon comment.

> - Transmitting the user-activity bit if present

Sorry... doesn't have this.

> Well, I guess I also complain about displays too..., I may as
> well list the DISPLAY processes that were left out of many clones:
> - the 8 or so Symbol color attributes

Nope... UI-View just displays the symbol that the sender intended. The
background colour of the label can tell you if it's a UI-View user or an
object. Hovering over a station will show most of the information about a
station. More details can be seen by double-clicking on it.

>  - Moving or dead reckoned versus fixed.

It doesn't do dead reckoning,

>  - message or non message capable (trackers vs users)

There isn't anything to do this automatically.

>  - Fresh, stale or Old versus new

If you hover over a station, it indicates how long since it was last heard.

>  - Objects versus stations

Objects have a different label background colour.

> - own objects versus other station's objects

You just have to hover over an object to see the owner.

>  - Special, priority and emergency stations

I don't know what a special or priority station is. One sending an emergency
beacon uses the emergency symbol. There isn't anything built into UI-View to
make it apparent.

> - Display of stations activity bits (user present)

As mentioned above, no.

> - Vicinity plotting for packets without position info
> - Position ambiguity for things with less precision

UI-View shows stations with ambiguous locations as if zeros were entered, so
in the northern hemisphere. It only becomes apparent that it's sending an
ambiguous position if you hover or double-click on it.

> - A consistent and easy to see map RANGE scale

Just enable the range scale. You can also measure distances on the map.
Naturally, you just have to hover over any station object or whatever to see
the distance from your own location.

> - Display of PHG data for network visualization

Yes. A readily available add-on is required.

> - Display of the stations individual ALOHA circle

Yes. A readily available add-on is required.

> Oh well, I run on...

That's OK! I could do the same, but it would take a LONG time to list every 
little detail of what can be done with UI-View. Did I mention street level 
scrollable and zoomable maps for North America? UI-NWS is useful for users in 
the US and at least along the US-Canada border. NWSGet can display US weather 
radar imagery in UI-View with an add-on. I'm sure you see the "missing" items 
above as a major detriment. However, thousands of UI-View users worldwide are 
going to continue to use it until a better mousetrap comes along. Some would 
argue that it's already here (Xastir) but it just doesn't seem to have the 
same user base. Perhaps that will change. UI-View does a lot of things and 
does them well. I cringe every time you mention "the clones." No one is saying 
that UI-View (or any other APRS client) is perfect. All have their strengths. 
Perhaps some should be mothballed. UI-View isn't among that group yet.

73 es cul - Keith VE7GDH
--
"I may be lost, but I know exactly where I am!"





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