KD0TLS: Introduction to objects

  I've mentioned objects in a few times in other posts without explaining them. You have to start somewhere, after all. Objects are remotely-created icons, meaning that they don't originate from the icon itself. They can exist on either RF or -IS, or both. 

 Common examples that you'll see on aprs.fi are:

• Repeaters, along with frequency, offset, PL tone or CC
• Rest areas and medical aid stations in marathons
• severe storm cells

Examples of repeater objects in northern MN

 Some other potential EmComm-related uses of APRS objects could be relief stations, impassable roads, EOCs, volunteer sand-bagging locations, tornadoes, or field stations for search-and-rescue operations. 

 Other more mundane uses could be Hams In The Park locations, club meeting locations, Field Day stations, Hamfests, etc. In all of these cases, information can be attached (e.g. times, club callsigns, talk-in repeaters, etc.) to the object using COMMENT or STATUS fields when the object is created. And they can be created in advance of the event to inform the amateur community better.

 Objects save an operator from setting up a station (whether RF or -IS based) at that particular spot. They are usually renewed on a regular basis to keep them visible. If a repeater object is re-transmitted every two hours, it will not be visible at times to people who have their aprs.fi map set for a one-hour time period. RF-based objects usually need to be gated (i.e. the packet needs to be received by a gateway), though it's certainly possible to set up an object using the BEACON field and have it only appear to RF-based stations. Obviously, some consideration is called for here. You don't need to broadcast a repeater's location/existence every ten minutes -- yet at least one prominent local station does exactly that. 

 Repeater objects can be very useful to amateur operator travelers, informing them of local repeaters or repeaters they will encounter further down the road.

 The only way I know of to create an object is by using APRSIS32 or UI-View, but that's just a limitation of my experience. I'm not familiar with the more obscure capabilities of (for example) Linux-based APRS clients. It's entirely possible that Xastir or YAAC can create objects. And, as I've previously mentioned, an Android version of APRSIS32 is in beta stage right now. Once that's ready for prime time, most anyone with an Android smart-phone or tablet could create objects easily.

 KC0CAP has operated a gateway near Litchfield for several months that was used to maintain several repeater objects in the area. Unfortunately, it's been down for well over a week and seems to have been replaced by an iOS-based station incapable of generating objects. If you'd like to try your hand at creating objects, those repeaters might be a useful starting point. 

 It might also be good publicity for a club project to create an object for their repeater, possibly adding the URL of the club's website. Knowing how to do this is a useful skill for marathons, parades, and other public service events. 

 I (or the other contributors) will undoubtedly cover the "how-to" details of object creation in the future. This post is just intended to be an introduction to the topic, making the reader aware of the potential for this mostly-overlooked APRS packet tool. But there are enough local operators already familiar with APRSIS32 or UI-View for someone to experiment with objects on their own. Please feel free to write up your experiences and send them to kd0tls@amsat.org -- or any of the other contributors.