Metro APRS coverage continues to expand

Since I last wrote about this subject, the metro has gained and lost a few digipeaters and I-Gates. Of course, W0YC-5 (formerly W0YC-10) at the U of MN has been back in action for months now. Others stepped in to fill the gap, and most of those pieces of the network remain. Two new stellar machines have joined the effort in the past month or so: the WB0ZKB-3 digipeater in Maple Plain and the KE0CGZ digipeater and I-Gate in Prior Lake. WB0ZKB-3 picks up the woefully-neglected west, and most often feeds the KE0CGZ gateway. The KE0CGZ gateway is further fed by the Chaska WB0ZKB-10 and Shakopee KF0ZH digipeaters, and even the Woodbury K0JDD-1 digipeater seems to send its packets across town to the same I-Gate. 

This is the current, worst-case metro-area digipeater coverage. It reflects the coverage areas for HTs and mobiles in somewhat-obstructed locations: 

12/2014 worst-case metro area digipeater coverage

As you can see, there are gaps in the south and north-east, but these are actually covered by other gateways (some receive-only). I'd venture that a digipeater somewhere between Circle Pines and Forest Lake would find some use, if only to improve redundancy of the network. Bear in mind that this map doesn't include the coverage provided by gateways -- only digipeaters.

All of these machines contribute to the real-time VHF propagation effort by virtue of their packet data being available to the public. Each one is a virtual propagation beacon, but also one that automatically tracks which other "beacons" it can hear.

One sure way of examining coverage is to look at the path map of the individual digipeaters and gateways. These represent the the areas that the particular machine actually handled during December 2014. The more red the block, the more packets that came from that area. I'm just going to pick a few of the newer (and also some of the lesser-known) pieces of the network that make the local APRS network function. 

Let's start with the new KE0CGZ I-Gate in Prior Lake: 

It's almost too wide of an area to display clearly, but you can see that it gates packets from Eau Claire in Wisconsin, up to Saint Cloud, and down to Mankato and Rochester. Bear in mind that this map includes gated packets passed on by other digipeaters.

 Next, let's look at the path map for the new western digipeater, KB0ZKB-3: 

I-94 most of the way to Saint Cloud is covered, and the north-central areas are backed up to provide redundancy for other gateways if the direct path becomes difficult.

 The south-west digipeater, KB0ZKB-5, also repeats packets with decent coverage:

Hwy 212, and the southern passes of I-35 and Hwy169, are covered. And fill-in coverage for Hwy 52 is also provided.

Next, we can take a look at the other south-western digipeater, KF0ZH:

While concentrating on its local area, KF0ZH also manages to help fill in the western suburbs. Like KB0ZKB-5, its proximity to the KE0CGZ gateway ensures that the received packets are efficiently gated to the APRS-IS service -- from which they are available to the entire world. 

One of the previously-mentioned receive-only gateways in the NW metro is N0FKB. In spite of a lack of nearby digipeaters to feed it, it does a fine job of gating packets by itself: 

This is one of the gateways that helped fill in while W0YC was down. The metro core is well-covered, and the north-central metro is also backed up. While the more long-range coverage is sporadic, this can still serve to increase redundancy of the network coverage. 

Another of the metro I-Gates is KB0GTF-10 in Richfield:

This gateway covers the southern suburbs quite well, and contributes to the coverage of both the north-west and north-central areas of the metro. It further helps fill areas to the south-east that the Red Wing digipeater (KC0FXY-2) tends to struggle with. 

There are, of course, other gateways and digipeaters providing their niches. But this isn't intended to be an exhaustive examination; only a look at how a few elements work with each other to get the packets sent by hams "home". Some gateways are "part-time", possibly in operation while the individual running them is at work and their rig is sitting unused at home. Sometimes mobile hams will operate a digipeater out of their vehicle while driving, and in so doing help out the effort to sustain coverage.

All of these gateways and digipeaters are run on a completely voluntary basis. Very few are sponsored by clubs. Nobody is co-ordinating this effort. Individuals simply pitch in and make it work. 

If you're interested in joining this effort, KC0VRV wrote detailed instructions on how to set up a receive-only APRS gateway for this blog back in October. You could easily let your VHF rig provide coverage to your fellow hams while it's sitting there unused, and you don't even need to transmit. Just connect the audio to a computer that has internet access, install some software, and start gating packets. You could even use an old analogue scanner.

To check the path map for a particular digipeater or gateway, go to aprs.fi and zoom the map down to your local area. Then look at the toolbar on the right. You'll see an icon of a funnel (third from the bottom). This is the filter. Clicking it opens the filter options. Un-check the box marked "All stations", and check the box for either "Digipeaters" or "I-Gates" -- or both. This will show you only those kind of APRS stations. Next, left-click on a station. This brings up a dialogue box, and you should click "INFO" at the top. This takes you to a page displaying the packet data for the station. Click on "show map" to see the path map. You can further select the particular month you wish to see data for by using the drop down labelled "Select month" on the left toolbar. 

With this information, you can dig in to some of the machines that I left out, and also explore the rural area coverage.