Northeastern Wisconsin and UP of Michigan APRS Coverage Update

Northeastern Wisconsin and Michigan’s UP APRS Coverage 2011-02-12

A recent trip from Appleton, Wisconsin through Green Bay, Wisconsin up to Michigan’s Kewenau Peninsula (Houghton / Hancock, Michigan area) through places like Iron Mountain / Kingsford / Norway, Michigan and Crystal Falls, Michigan and through Amasa, Michigan – then Covington, Michigan and L’Anse and Baraga, Michgan allowed me to produce the APRS track on the left.  Our destination was the MTU (Michigan Technological University) Winter Carnival to tour the snow sculptures – some people call the ice sculptures – but they are mostly made of snow.  I graduated from Michigan Tech and wanted to show my new wife Jane (KD8KRS) what they looked like.  After the tour we returned to my childhood home of Iron River, Michigan for a nights rest and a GREAT meal at Alice’s.  The next morning after doing some photography at the Paint River forks we headed back to Appleton, Wisconsin.

For those not familiar with ham radio’s APRS (Automatic Packet Reporting System) here’s a quick lesson.  APRS in a nutshell allows a ham radio to transmit digital packets of information through the use of a little electronic box called a TNC )terminal node controller).  The TNC handles things like gathering data from a GPS sensor, conversion of the data to a digital format if needed and timing of transmission via the radio.  I happen to have been using a TinyTrak 4.  People generally refer to these as Tiny Tracker 4′s, but that’s not the actual name.

My settings are set to transmit a maximum of ever two minutes and / or at every turn of more than 15 degrees.  In practice I’m not sure this makes it into the Google map at exactly that pace.  There are a number of reasons for this.  One is that there can be many APRS trackers active on the network at any one time.  Best signal wins – and only one signal at a time wins.  There can be interference, network down times, programming errors in the TNC, etc..

The track on the APRS map that I use ( http://aprs.fi/?lat=44.2764&lng=-88.4280&mt=roadmap&z=11&timerange=3600 ) is defined by blue bands connecting red dots.  The red dots indicate points of APRS transmission.  On a live map, hovering over the red dots with produce ANOTHER red line – this is a connection between the APRS transmission and the station that heard the APRS transmission.

On the map in this blog post I was rather suprised by the relatively good coverage through the wilds of the sparsely settled UP of Michigan.  Believe me.  Between Crystal Falls, Michigan and L’Anse, Michigan – there just are not a lot of houses that might contain APRS receivers.  Now, my APRS settings are configured so that I instruct any APRS receiver that receives my APRS signal and data to please re-transmit the data up to two times.  These are called “hops”.  Hops are powerful but dangerous.  The more hops you specify the more likely it is that your data eventually will make it into the APRS database in the internet.  You see, some APRS receivers, but not all are connected to the internet.  For example, my ham radio in my car can receive and re-transmit others’ data but it is not connected to the internet.  Hops can be dangerous because the more hops the more congestion on the network.  Too much congestion and everyone looses.  I do wonder if there will need to be official rules and guidelines developed for times of emergency use such as Skywarn activations for severe storm spotting.  Of maybe some sort of “emergency overide coe” that certain devises are allowed to transmit at these times…

I also was somewhat suprised – but not shocked – that there was not as good coverage comming back down through northeastern (NE) Wisconsin.  I do a good amount of travel over these roads going to see friends, fishing, boating, etc..  It would be quite nice to have good coverage for times of severe storms.  Skywarn net control operators should be aware of this lack of coverage for several reasons.  One is that they need to be aware that the last red dot that showed up on the APRS Google map may not be the EXACT location of the vehicle or person being tracked.  This can be important when taking severe storm reports.

For those that wonder, or those that have a Tiny Tracker TNC, the following are my settings at the time that this track was made.  I do not represent that these settings are ideal for everyone or anyone.  Each person that uses an APRS tracker needs to determine their particular needs.  They also need to not produce network congestion to the extent practical.  I must admit that I am still doing research into these settings and am still adjusting them.  This post will not deal with specific setting defenitions.  Rather it is meant as documenation of my settings so that you may analyze them and the track and perhaps improve your track.