Originally Posted by DaveInDenver
So what's the story with this APRS? I know about it in theory and everyone talks about being able to report a location in the backcountry. But don't you need a packet-capable repeater for it to work? Are most repeaters capable of this? What about that funky Google reporting, does the digital repeater then also need to be on the Internet? Just wondering, I know pretty much nothing about how this stuff works. I don't have GPS box and I'm not about to buy and drag a laptop with me. I tolerate having a computer at home, but I'm definitely not going to have one with me in the truck.
I have a bit of book knowledge, but not *any* real-world experience.
APRS is packet based, and, basically routes packets between radios (TNC's) and "digipeaters". There are a fair number of digipeaters around, but they're not nearly as prevalent as regular repeaters.
APRS rigs update each other, so you'll always see "local" information. You, or a rig within a small number of "hops", must be able to get to a internet-enabled-digipeater for your packets to reach the Google-enabled map.
New Mexico has some of the best coverage in the states (digipeaters on most key high-points). I have not checked the coverage maps of Colorado & Utah yet.
In addition to location updates, you can send "email" to local stations or even internet email addresses. The messages are limited in length (think texting on your cell phone).
In SAR & emergency operations, APRS is commonly used to keep track of tactical (local) locations of resources. A computer at HQ receives (and sends) updates, and displays a map. The internet is not necessary at all for this.
Even though many TNC's can act as digipeaters, convention is that they are NOT configured this way -- primarily because it can cause dramatic traffic increases (congestion on the airwaves). There have been recent protocol changes to help mitigate this.
One of the nice features (for me) of the TM-D710A is that that NO computer is necessary for common APRS scenarios (sending/receiving location updates, sending/receiving messages, viewing & communicating with local "objects"). I have no plans to permanently mount a laptop/carputer in my 80. I will probably carry around a laptop to reprogram as necessary, at least initially.
If you look at the link above, centered on the Denver area, you'll see a few "tracks" of mobile rigs. A lot of the "noise" on the map is static weather stations, and static digipeaters. You can turn off different types of objects so they don't clutter your screen.
Once I get it all installed, I'll take it out and see how it works in real life. I hope the coverage in the places we go (non-urban) is sufficient to be useful to those NOT on the trip. Hey -- someone has to be the vanguard!