APRS Tracking & Mapping
An APRS client for amateur radio operators - a tool that runs on your own device.
It ships with no server address: enter your own APRS-IS server, or use a
Bluetooth TNC / sound card / direct Icom connection.
That number is every packet the world’s APRS stations have relayed so far — radio waves cross the sky and end up on this planet, and the next one is yours to send.
APRSlocus 2.0 released 2.0 is out · Download now →
📡 APRSNETCN OA · test round
Saturday 17 October, 00:00 to 23:59 Beijing time. Network and RF both count, RF first. Address the message to BG7LZQ-3 and send it the CQ CNNET way.
The first round of APRSNETCN OA is this Saturday. Stay on for the day, send one packet to the week's duty callsign, and you are on the list.
📡 When, and who is on duty
📮 How to join
Address the message to BG7LZQ-3.
Send CQ CNNET BG7XXX from OL62 with your own call and your own grid. When the duty station answers with an ACK, send U CNNET.
You can also send CNNET BG7XXX from OL62 and skip the CQ step.
A grid of 4 or 6 characters both work, for example OL62 or OL62AA. If a packet arrives without a grid, the duty station answers with a hint; send it once more with the grid in.
Anything you want to pass on to the duty station goes after the grid. That sentence shows up next to your callsign on the roster.
Packets over the network and packets over RF both count, RF first. An RF packet records the digipeaters it went through.
You need a valid callsign and licence, and please follow your local regulations.
📋 What shows up
The duty station answers every check-in with an ACK.
Your callsign then appears on the activity page roster, with your grid and the time it arrived.
The roster image and the grid image can be downloaded the same day.
🙋 About this round
This is the first round, so the flow will keep changing. The activity page always carries the current version.
No scoring, no leaderboard, and no commercial use.
If you miss this one, there is another round next Saturday.
In APRSLocus, open the Messages page and set the recipient to the duty callsign.
The roster for the day is on the activity page. Open the activity page
✅ The Qingling channel is back
The 2.2.0 build published on the Qingling (清零) channel by mistake has been taken down, and the channel works normally again.
Checking for updates now returns the latest stable version, 2.1.6. If you installed 2.2.0, uninstall it first, then install 2.1.6.
🥚 A small easter egg in 2.1.0: tap, and the planet turns around
The egg is on the About page — the spot you most likely pass every day.
That slowly turning star on the cover is not a picture. Give it a light tap: it shudders, turns around, and drops you into a page of story. There is a planet turning there too, a number that keeps climbing, people who keep watch on the airwaves — and the people who built this thing alongside them.
There is sound on that page; turn your speakers up. No long press, no five-second wait — one tap and the story arrives. Changed your mind? One more tap turns the cover back, and the story stays closed.
The rest is yours to see.
📮 We would like to hear from you
APRSLocus has walked a while with 620+ users now. Where it goes next is partly your call: what feels awkward, what is missing, what we should fix first.
💬 Official QQ group 925025834
Questions, ideas, or just a "copy that": you are welcome to drop in.
🎵 A song for you: 启航的歌 (Set Sail)
The planet is still turning, the number is still climbing.
Thank you, everyone still listening.
The APRSLocus team
October 2026
The all-new UI 2.0: a full-screen map with floating capsule navigation and draggable panels. See the full promo page →
Position tracking, beacon reporting, messaging, group chat — all the APRS essentials, built to be straightforward.
Maps & tracking
Many tile sources: AMap tiles, AMap satellite, Vector, Carto (light/dark/voyager), OSM (standard/humanitarian), OpenTopo, and Esri. One marker per station (clustering removed in v1.6.149), with trail playback support; the heatmap shows density when zoomed out.
A navigation-style page built for glancing at while driving: large heading / distance / speed readouts, a nearby-stations panel, and the target station centred.
Download the tiles of the current view to the device (resumable, 200k tiles per region) and keep the map with no network at all; a four-step fallback keeps it readable and clickable.
Messaging & gateway
One-tap position reporting in standard APRS 1.0 format. Auto-includes altitude, speed, heading, and battery level. Report interval is configurable.
Private and group chat in a unified conversation list with ACK confirmation. Supports group invites, member management, unread badges, and Chinese text.
Built-in multi-engine translation that works out of the box on a free endpoint, no API key required. Translate both incoming and outgoing messages, compare against the original, or translate your text into the other station's language before sending.
Relays RF packets into APRS-IS, tagging them with qAr / qAR; loop protection is built in (packets already carrying TCPIP* or a q-construct are never echoed back), and the same frame is injected once per 30 seconds. Optional two-way mode sends messages to stations recently heard on RF.
Stations & data
Recognizes station devices via the official aprs.org database (tocalls): vendor + model + device class (rig / HT / tracker / app / gateway…). Filter by status, type, device class or exact model; jump to QRZ callsign DB or aprs.fi for tracks from the details page.
Raw packets displayed in monospace with long-press copy. Parsed results sorted by type: position, message, weather, status. Built-in hierarchical logs for debugging.
Internet (APRS-IS), Bluetooth / serial TNC (KISS), sound-card AFSK 1200 (Bell 202 software TNC), Kenwood $PKWDWPL waypoints (receive-only), and WLAN radio direct link (supporting IC-705 / IC-9700 / IC-7610 / IC-905 over Wi-Fi / Ethernet with CI-V and LAN audio). Multiple links can receive simultaneously, while the transmit link is picked separately.
A weather panel whose dynamic background follows the actual conditions, station statistics (latest spot, farthest distance, packet rate), and an honors wall.
One-tap ADIF export — the standard amateur-radio log interchange format — with a configurable frequency, ready to import into other logging software.
An HF panel plus a standalone widget: SFI / Kp / A index, sunspots, X-rays, solar wind, and day/night conditions for four band pairs at a glance. Data comes from hamqsl.com (N0NBH) with a 30-minute cache.
System & experience
Auto-connects to APRS-IS public servers over TCP or WebSocket. Progressive reconnect: 8 → 16 → 32 → 60 seconds. Android uses a foreground service to stay online.
In-app update checker with two channels (GitHub / GitCode). Platform-aware download routing and historical version access.
Simplified Chinese / Traditional Chinese / English / Japanese / Indonesian / Spanish UI, dark mode, custom accent colors, scalable UI (85%–130%). Six-step onboarding wizard on first launch.
Android home-screen widgets: weather (four adaptive sizes), HF propagation and system status. The widgets never open a connection themselves — the app pushes a snapshot to them, which keeps them cheap on battery.
Themes go beyond colour: icons, text and your own background image (17 colour tokens), exported as JSON to share; settings and data back up as one file for a one-tap restore.
Ready-made packages for Android and Windows. Download and go.
On first open, the onboarding wizard walks you through the setup. Fill in the steps and you'll be connected to APRS-IS and reporting your position.
中文 / English / Follow System
Try demo mode first
e.g. BG7LZQ-3, choose SSID suffix
Car / House / Person / Weather Station …
Filter stations by country / region
Enter Passcode, done — auto-connect
-1 works for basic connectivity, but an unverified Passcode cannot send or receive messages properly. Visit
APRS Passcode Generator to generate your own Passcode.
APRS 1.0 compliant, compatible with mainstream APRS software. All icons from the official symbol table.
BG7LZQ-3>APALOC,TCPIP*:!2148.90N/11049.14E/> /A=000328 090/050 Bat:70% APRSlocus v1.6.18APALOC — Identifies this station as APRSlocus/A=000328 — Altitude in feet090/050 — Course / SpeedBat:70% — Battery levelHighlights of recent releases — dozens of maintenance releases in between are folded in; see GitHub Releases for the full history.
SAT=nn is an optional comment field, fed by whichever source is supplying the position — phone GPS (Android reads the satellites used in the fix) or the external GPS module's GGA sentence. Off by default, and nothing is sent when the source does not provide it, rather than a zero that reads as "no satellites".GSA, and an explicit "not reported"), module time (UTC), the trigger sentence and the latest raw sentence are all out in the open; the age ("N seconds ago") refreshes every second, so a stalled stream shows at a glance how long ago the last fix was.RMC / GGA / GLL / ZDA / GSA / VTG) over Bluetooth SPP or a USB serial port, used for this device's own position and receive-only. Position priority: simulated > external module > Garmin watch > phone GPS.stream, so the backend answered with one plain JSON blob; the app saw "no stream" and sent the very same request a second time — every round waited twice as long and paid twice the tokens. The streaming request now really carries stream: one request, shown as it arrives, with the same automatic fallback when a backend does not accept it — never fewer replies.https://… / www.…) become tappable links, consistently in the station list, the station detail page and the map info window.>APRSlocus CONNECT … frame every 15 seconds and then a second frame with your custom status — a wasted frame that also made the status on aprs.fi flip between the two. Now a single frame is sent, whichever has content: custom text if set, otherwise the built-in default; the CONNECT identity frame goes out once, at the moment of connecting. A custom frame that fails to write is still retried automatically, so your status is never overwritten by CONNECT.stream, or on the Web) the app falls back to a whole-answer request plus a typewriter effect for the same feel — never fewer replies. A switch in Settings → Interface (on by default) controls it.360°.strategy_add_point / strategy_add_line and friends, and each element lands on every member's map and is broadcast to the group. Use list_strategy to see what is there, edit or delete by id, or strategy_clear to wipe the layer. The read-only list_strategy needs no confirmation; the frame-sending writes still need the "allow sending"/"allow settings" permissions and a per-action confirmation.WIDE1-1,WIDE2-1. The page now has an “RF digipeater path” input, sharing the same key and semantics as the TNC/audio pages (empty = no digipeater); changes take effect immediately.aprslocus) and Hong Kong (aprslocushk) buckets; Hong Kong is served over the custom domain aprslocushk.oss.theez.top..apk / .ipa downloads with ApkDownloadForbidden (.exe is fine). Uploads now add a .bin suffix to those objects and the index download URLs point at xxx.apk.bin, while asset names stay unchanged -- no client change needed. The release self-check now really downloads each asset.aprslocus.oss-cn-guangzhou.aliyuncs.com), which is fast in mainland China. It is off by default and must be picked on the update page.publish-oss job that uploads the installers plus a GitHub-format releases index; credentials come only from GitHub Secrets and are never committed.updateChannelBases, shared by the update page and the launch prompt. The Qingling channel uses HTTPS with a pinned self-signed certificate (pinning only that one host; other channels keep the default trust chain): encrypted and tamper-proof, with no domain, filing or purchased cert needed. GitHub stays the default.flutter_windows.dll and data/, so it did nothing when opened) -> now a single-file installer with if-no-files-found: error; the iOS test artifact dropped its fork suffix -> the suffix is kept. Also: v2.0.50 was already released, so this feature bumps the version to 2.0.51.onEditingComplete, which fires on Enter but not on focus loss. They now settle on blur; Enter still confirms immediately, and the output-amplitude commit rebuilds only the modulator without interrupting receive. The same fix lands for the IC-705 radio fields and the TNC serial baud.output amplitude — the gain that decides clipping — was not editable in the UI, while both warnings said to adjust it. The TX card now has an output-amplitude field that takes effect immediately (rebuilding only the modulator, without interrupting receive). It also shows the current TX source (connected ≠ transmitting) and notes that the app never keys the radio PTT (use VOX or a data-port cable).Flexible, so short text left free space and the chevron drifted left; switching to a tight Expanded pins it to the right and aligns the description column too.groupChatAllowed is always on; on RF (TNC / audio) strategy frames are sent ack-requesting and delivery is judged by teammates' standard auto-ack; unacked after 90s is treated as "unconfirmed" (a peer may have auto-ack off) and can be resent manually from the strategy map page.$M, long lines auto-chunked, every frame ≤ 67 chars); elements support jump-to-navigation and editing attached info, and "clear layer" syncs to the whole group.Tianditu Vector (vec), Tianditu Imagery (img) and Tianditu Terrain (ter). Their base tiles carry no place labels; text lives in separate transparent annotation layers (cva/cia/cta), so each basemap is composited with its matching overlay (vector+cva, imagery+cia, terrain+cta). Base and annotation are cached separately and downloaded together offline, so you never get a map with no place names. Tianditu is measured as WGS-84 (zero offset vs Esri/OSM imagery), so it is not GCJ-shifted and falls back to OSM; tiles go up to z18. The key is injected at build time (CI Secret TIANDITU_KEY), never committed to source; when absent the map falls back to OSM and stays usable.OpenTopo Terrain (with contours, moved out of "Others"), Esri Topo (contours) (roads + labels + contours, closest to a paper contour map), Esri Shaded Relief (pure relief, cleanest for overall terrain) and Esri Hillshade (valley direction only). All four are key-free, offline-downloadable and fall back to OSM; being native WGS-84 international tiles, they are not GCJ-shifted and will not offset.scl=2, 512px), Carto / OSM / Esri / Tencent / Gaode satellite only serve 256px — the source was not the cause. The real issue was level selection: the map used zoom.floor(), so the whole [z, z+1) band pulled level-z tiles, stretching the source up to 1.93× at z=12.9 and then 2–3× more by screen pixel density — a 4–6× physical upscale, hence blur. It now uses zoom.round(): the upscale is capped at √2≈1.41× and the upper half downscales. Applies to every source.ReportActions (auto-report switch + report-now button); the duplicate implementations and the false "reported" toast are gone. Settings now use the unified "自动上报" wording with a hint pointing back to the main UI.IMPORTANCE_LOW) persistent notification, which the system neither vibrates nor banners for — so with the phone in a pocket (the usual state during a fall or while driving) it was not noticed at all. The strong reminder uses its own high-priority channel; Android needs the VIBRATE permission (added).ts(12), whose default color is dark, on an equally dark background - dark on dark and unreadable. It is now explicit white text (one more instance of the same bug in the settings pages is fixed too).rotate.aprs2.net / 14580 / -1 - the app presets and recommends no server; re-running the wizard still restores your saved values.HitTestBehavior.opaque); with translucent both receive the pointer - tap selects the station, drag/pinch moves the map; applied to both the raster and vector map. The vector-map heatmap never worked either (it was excluded by !_usePluginMap); the vector map draws it now, projected with the flutter_map camera. "Start from a favourite station" opening a black screen was fixed too: it closes the New conversation dialog first and then closed one again after picking, popping the whole messages page - now the dialog is only closed when one is open. No system notification when picking a simulated point was fixed too: setting the position manually stopped the foreground service without restarting keep-alive - it is restarted now.key for identity reuse, and callsign labels are skipped when dense. Tile dragging was fixed too (tile loads are deferred until the gesture ends), as was the packet page (each row restarted a fade-in whose duration grew with the row index).TEL k=v ..., so the app can add fields without touching the firmware (unknown keys are skipped, empty values are not sent, and the box shows --, never a fake 0). Also: IS rx-only now explains itself in three places (home set pass, the server own words on the SYS page, and the app event log) with the fix (use the passcode of the base callsign), and countdowns now tick locally on the box with status pushed every 5 s.armeabi-v7a means (or which row to choose) pushes the app's job onto the user. The page now picks the package matching this device's CPU by itself (Abi.current(), no platform channel needed) and downloads it in-app: a 32-bit device gets the 32-bit build, an emulator gets x86_64, and no one sees "incompatible with this device" after downloading. When the architecture cannot be determined it falls back to the pre-split behaviour, so an unknown device never ends up with no package at all..apk in the asset list and assets come back in ascending name order, where . sorts before _ — so the 64-bit build is always first, an invariant with a dedicated check and self-test._armeabi-v7a directly. One display fix came along: while downloading, the hero card and the card below it each drew a progress bar for the same download (it read as two tasks); now there is one.livetrack.garmin.com and the China-region (mainland) one at livetrack.garmin.cn. Only the international host was recognised, so a link shared from the China-region app just said "no LiveTrack link found" — and not a single network request was ever made, making the feature silently dead. All three host forms are accepted now (.com / .cn / .com.cn), including a link without https:// (which is what copying from a chat window usually gives), and two fallbacks were added: parsing searches the whole document for trackPoints (the China-region and older share pages are not Next.js streaming chunks), and fetching still follows the 301 redirect..SF NS Text). When that name fails to resolve, no fallback is left for Chinese, so the map page and the settings pages came out as garbage. macOS now uses the system default font instead (it is SF either way, so nothing looks different — the OS just does the font picking and CJK fallback), and the CJK fallback list was completed (PingFang SC / Microsoft YaHei / Noto Sans CJK SC …). Monospace areas (packets, logs, the honour wall) got CJK fallbacks as well — monospace faces carry no Chinese glyphs either. A new check refuses that private family name and requires the three platforms' CJK families.STEPS=, off by default). A new activity leaderboard sits above the honour wall in Settings: today's steps, and tapping a row opens the station detail. You cannot see the board without contributing — every number there was sent by someone else, and receiving without sending should not get you other people's data for free. The page states plainly that it ranks the neighbours you can hear, not the whole network..part file and renames atomically, so an interrupted download never leaves an uninstallable package behind.HR= in the beacon comment: a BLE chest strap or Garmin LiveTrack), and the day detail page gains three polylines — heart rate / speed / distance — each of which can be toggled, or the whole panel hidden. A vertical cursor follows playback, and the heart-rate row shows the day's min–max. Gaps with no reading are drawn as breaks, not straight lines. A day can hold 40,000 points, so the curves are bucketed once to 240 points on entry; playback stays smooth.2.0.5 was compared against the tag v2.0.5, which never matches); the comparison now ignores the v prefix. (6) The update channel now defaults to GitHub (one tap switches back to the mirror).000/000 PHG2130 /A=000033), and the reference implementation (aprslib) reports phg as missing entirely with PHG2130 left as ordinary comment text — meaning third-party maps showed no coverage and the feature did nothing. Two independent traps caused it: (1) APRS101 defines PHG / /A= / CsT as fixed-length data extensions that must be glued to the symbol with no separators (real stations look like …ErPHG1460/A=000071); (2) CsT and PHG compete for the same "start of comment" slot — parsers match ^\d{3}/\d{3} first and, once it hits, only look for a DF report and never search for PHG, so even glued together PHG stays unreadable while 000/000 comes first.!2155.17N/11052.40EbPHG2130/A=000033 Bat:22% (spaces appear only between the block and the comment). One trade-off: a mobile station that also fills in PHG shows no speed/bearing on aprs.fi — both need that single "start of comment" slot and cannot coexist; stations without PHG are unaffected. The beacon packet's third-party compatibility test now runs in CI, so this class of "compiles, analyze is green, third parties cannot read it" bug has a guard.PHGphgd; leaving them empty sends nothing at all. The encoding follows the spec: power uses the largest step that does not exceed the real value (25 W reports 25, and 30 W still reports 25 — over-reporting claims coverage you do not have) and antenna height snaps to 10×2ⁿ feet. The settings page echoes back what will actually be encoded, since quantisation is invisible and there would otherwise be no way to know what went out. In the packet the extension sits where the spec puts it: PHGphgd comes immediately after the symbol (right after !lat/lon/symbol, ahead of the /A= altitude and any other comment text), matching the standard packet …:!2216.45N/11113.90ErPHG5950 — third-party parsers look for PHG as a data extension at the start of the comment, and reading it after other fields fails.APRSlocus CONNECT vX.Y.Z online frame. A status packet is a frame of its own (>-prefixed, carrying no coordinates, and it does not move you on aprs.fi), so it can be sent even without a fix. Transmitting reads the current contents of the field directly instead of relying on input-event timing — with an IME composing text the app used to send the default frame although the user had typed something. A manually entered altitude was added too: empty follows the fix (the default is unchanged), and the settings page shows the /A=aaaaaa fragment that will be sent.--, making "absent" and "not received" look identical.@video marker plays in-app (Android / iOS / macOS; Windows / Linux / Web fall back to the external browser). Older versions simply show that line as plain text (still a link).positionSourceNow) whose priority is written in both places — simulated/manual › Garmin (while the watch has live data) › phone GPS — and the beacon page option is renamed to "Phone GPS" (matching the Devices page), with an "In use now: …" line.EXTRA_TEXT, while plenty of apps (some Garmin versions, browsers) put it in clipData — a null read made the whole share go silent, which is exactly the intermittent mechanism. (2) No text meant a silent return, with neither a message nor a log line. (3) A cold-start race: the share can arrive before the UI registers the callback, so the callback is null and the event is dropped (the "still no feedback after the hand-off") — it is now "call if present, otherwise store", with the UI consuming it once it is up. Link detection was widened too: the short code is unbounded in length and case-insensitive.gar.mn/…) never got through. Garmin's Share button produces a short link, but the app only accepted the long form and the Android share target only allowed that host — so "Share → APRSlocus" did nothing. Both forms are recognised now (including a bare gar.mn/xxx with no scheme), redirects are followed, and the token is masked before logging, because a share link is the credential for reading a live position.HR=nn to the position comment — and sends nothing without a reading (HR=0 would read as "pulse 0"). It does not fight with the TNC link: TNC uses classic Bluetooth SPP while heart rate uses BLE GATT, they run in parallel, classic discovery (which would tear down the SPP link) is never used, and a device already held by TNC is rejected with a reason.contain whenever "container width / card height > 1.62" — but the card height is capped at 300 while the container reaches 600, so that held on every screen 600 wide or more: the photo shrank to a band in the middle with 75px of blank space on each side, and in landscape the logo card sat on that left gap (the "logo backdrop isn't filled" report). It is now cover + topCenter, filling the card while keeping the snow-capped summit. (3) The messages page switched columns by orientation (any landscape screen got two columns), but the 2.0 landscape shell puts it in the ≤560 left pane (often 200–280 on a phone), where the fixed 280 list column squeezed the chat column to a negative width. Column switching now looks only at the available width, the list column follows its container, and a new narrow-container degradation lets the callsign ellipsise and wraps the group action chips onto their own row (nothing hidden).topBase+46, right on top of the immersive-map entry. Merging it into the same column fixed that, but measuring the real geometry showed it was one pixel from intersecting the legend — a layout that relies on "it just barely fits" breaks with a longer language or a different text scale. So both full-screen map views now use a one-off bottom sheet: with overlays on every side there is no position where a floating card is safe. The sheet only fires when the page is actually in the foreground.check_landscape_layout.py no longer counts occurrences of leftInset but judges the structure instead — counting implementation details punishes refactoring, and it produced a false failure this time.tool/check_guides.py, ties the guide table, the six-locale text, the generated l10n output and the page call-sites together — missing any one of them breaks neither the build nor the tests, it just means the guide never appears. The check caught three real problems the moment it was writtenwidth × 0.64, 196–300) and switches to “fit entirely” on ultra-wide screens so the volcano is never cropped; the hero and body now share one width-capped container (600) on desktoptheez.top and the "site owner" label are removed, and the globe button now opens the app's own website (already listed under Feedback)reverse() only changes the status — the value moves a frame later — so the page underneath showed through for one full frame (visible only with the material or a background image enabled)From Passcode to battery drain — everything we could think of. The full 23 questions, grouped by topic, live in the Help Center.
Most likely an unverified Passcode. Entering -1 only lets you connect — it won't work for messaging. Visit APRS Passcode Generator to generate your own Passcode and enter it in Connection Settings. If the server returns unverified, a yellow banner appears at the top of the home page — tap "Go to Settings" to fix it.
In step 6 of the wizard or under Settings → Connection, use your full callsign (including SSID suffix, e.g. BG7LZQ-3) to generate a Passcode, then paste it in.
The app has built-in progressive reconnect (8 → 16 → 32 → 60 seconds). If it persists, check your network, make sure the server address (default rotate.aprs2.net:14580) and port aren't blocked, or try a different server in Connection Settings.
Check if your target country/region is selected in the Receive Filter, and verify that the receive range (lat/lon + radius) covers your location. By default, only Chinese (B-prefix) stations are received.
Android uses a foreground service for continuous positioning. You can adjust the report interval in Location / Beacon settings, or switch to manual reporting to reduce power usage. The notification bar has a one-tap "Exit" button.
For best compatibility on Windows, switch to Vector Map (no API key needed) or use Carto / OSM / Esri layers in Display → Map Type.
Since v1.5.2, Android builds use the official release signature. CI and local builds use the same key — just install over the old version. If upgrading from a much older build, uninstall and reinstall.
Star, open an issue, send a PR, or join the QQ group / Discord — all welcome.
Thank you to everyone who makes APRSlocus better.
Want to be on this list? Translate, open a PR, or file a bug — see the contributing guide →
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