Watch APRS travel across the air
APRS turns short bursts of amateur-radio data into a living picture of stations, vehicles, weather, messages and radio coverage. This page explains what you are seeing and connects you to real activity around my K5NWZ station in Loveland, Colorado.
144.390 MHz • Northern Colorado • Read-only public view
What Is APRS?
APRS is the Automatic Packet Reporting System. Amateur-radio stations use it to exchange small packets of useful information over the air. A packet may contain a position, weather report, short text message, telemetry reading, station status or information about a local radio service.
Unlike a voice conversation, APRS stations normally transmit short automatic reports. Nearby radios and internet gateways collect those reports and place them on a shared network. The result is a real-time view of what radio stations are doing and where their signals are being heard.
Explore This Page
- Hear, see and decode APRS on the SDR
- How an APRS packet travels
- What appears on APRS
- Live K5NWZ and regional activity
- How to read the map and station reports
- Why APRS is useful
- How to get started
- APRS glossary
Hear, See and Decode APRS
APRS is packet radio you can both hear and see. A transmission is normally a short 1200-baud Bell 202 AFSK burst: two rapidly changing audio tones carrying an AX.25 frame. We will show it using a verified capture from this station’s own K5NWZ OpenWebRX waterfall and decoder.
Keep your volume moderate. The reference burst lasts about one second.
Try it on the K5NWZ OpenWebRX receiver
- Open the guided SDR page in another window.
- Choose SDR 1 APRS 2m / 144.390 (Auto Decode) from the Receiver profile list.
- If the decoder is not already visible, choose DIG → Packet.
- Watch for a short bright burst, listen to the tones and compare the decoded AX.25 line with the callsign, path and packet details explained on this page.
How an APRS Packet Travels
Not every packet uses every step. K5NWZ may hear a station directly, receive it after a digipeater repeats it, or see it through the APRS internet network.
📻 Direct RF
K5NWZ heard the transmitting station itself over 144.390 MHz. Direct packets are especially useful for measuring the real performance of the local antenna and receiver.
🗼 Via digipeater
Another APRS station heard the packet and repeated it. The path shows which digipeaters helped the signal travel farther across the region.
🌐 APRS-IS
The report arrived through the worldwide APRS internet service. It may have started on RF somewhere else before an internet gateway forwarded it.
What Can Appear on APRS?
Cars, off-road vehicles, bicycles, boats and portable operators can report position, speed and direction.
Temperature, wind, pressure, humidity and rainfall can be transmitted as APRS weather packets.
Operators can exchange short addressed messages, acknowledgements and bulletins.
Home stations, digipeaters, gateways, repeaters and other radio resources announce their status.
Voltage, temperature, channel activity and other measurements can be carried in compact packets.
Events, hazards, repeaters, meeting locations and other points of interest can appear as named objects.
Live K5NWZ and Regional APRS Activity
The links below open real APRS network information for K5NWZ-1 and the surrounding stations. They are public, read-only views: visitors cannot transmit, send messages, change radio settings or access my station controls.
Stations received by K5NWZ-1
This interactive map is fed by my personal K5NWZ APRS station in Loveland, Colorado. Blue markers were heard through my 144.390 MHz radio; orange markers arrived through my APRS-IS connection. The green home marker is K5NWZ-1.
Connecting to the station’s read-only public feed. If it is briefly unavailable, the last known map remains visible.
Working now
Pan, zoom, filter by source and select a marker to see callsign, path, packet count, distance, bearing and comment.
Live station feed
The map, receiver status and recent packet list update automatically from a safe read-only feed. Visitors cannot transmit or reach station controls.
Coverage analysis next
Range rings, direct-RF highlighting, bearing sectors, station density and before-and-after antenna comparisons.
Recent activity received by K5NWZ-1
Loading recent packets…
Receiver snapshot
Loading receiver counters…
Counts reset whenever the station service restarts. Recent-map records represent the latest positioned packets, not every station ever heard.
How to Read APRS Reports
A callsign often includes an SSID, the number after the dash. It distinguishes more than one APRS station or function operated under the same callsign. For example, a home gateway, vehicle and handheld radio may all use the same base callsign with different SSIDs.
- Last heard tells you when the most recent packet arrived.
- Path lists digipeaters and gateways that handled the packet. An asterisk marks a station that repeated it.
- Symbol suggests the station type, such as a vehicle, house, weather station or digipeater.
- Comment or status may describe the operator, equipment, frequency or purpose of the station.
- Distance and bearing show how far away the reported position is and in which direction.
Why APRS Is Useful
APRS is more than dots on a map. It gives amateur-radio operators a shared situational-awareness network that can continue moving useful local information over radio. It is used for event support, public-service communication, weather reporting, vehicle tracking, search-and-rescue support, telemetry and everyday experimentation.
For my station, APRS also provides a practical way to study two-meter coverage. By separating stations heard directly from those received through digipeaters or the internet, I can see what the antenna and receiver are actually hearing and compare performance when station equipment changes.
APRS and Packet Radio
APRS grew from the same AX.25 packet-radio technology used by traditional packet stations. Traditional packet radio often creates a connected session with a mailbox, node or bulletin-board system. APRS normally uses short, unconnected broadcasts so many stations can hear and use the same report. Both are excellent ways to explore digital networking over radio.
Visit my Packet Radio page to learn about connected packet sessions, BBS systems, mailboxes and the live 145.050 MHz packet feed.
How to Get Started
You can begin by simply watching APRS activity. Open the regional map above, select stations and compare their paths and last-heard times. To receive APRS yourself, you need a two-meter receiver or transceiver, an antenna and software or a TNC capable of decoding 1200-baud AX.25 packets on the North American APRS frequency of 144.390 MHz.
Many modern amateur radios include APRS or packet functions. A computer with a sound interface and software modem can also decode packets. Before transmitting, make sure your callsign, beacon rate, path, symbol and comment are configured responsibly so the shared radio channel is not overloaded.
APRS Glossary
Come Explore APRS
Keep this page open while you listen on 144.390 MHz. Select stations, follow their paths and watch how radio and internet gateways work together. The next phase of this page will bring the K5NWZ direct-RF, digipeater and APRS-IS feeds together in one interactive view.
Data links: public APRS network information for K5NWZ-1 and nearby stations is provided through APRS.fi. The upcoming K5NWZ map will remain read-only and will not expose messaging, beaconing or station controls.