ATAK Plugin — PLSS Grid
Download PLSS Grid 0.5 (pick the one matching your ATAK-CIV version, sideload, then load it in ATAK's Plugins manager):
- ATAK-CIV 5.6: https://github.com/takwerx/plss-grid/releases/download/v0.5/ATAK-Plugin-PLSS-0.5--5.6.0-civ-release.apk
- ATAK-CIV 5.7: https://github.com/takwerx/plss-grid/releases/download/v0.5/ATAK-Plugin-PLSS-0.5--5.7.0-civ-release.apk
- ATAK-CIV 5.8: https://github.com/takwerx/plss-grid/releases/download/v0.5/ATAK-Plugin-PLSS-0.5--5.8.0-civ-release.apk
All releases: https://github.com/takwerx/plss-grid/releases
User guide with screenshots: docs/USER_GUIDE.md (https://github.com/takwerx/plss-grid/blob/main/docs/USER_GUIDE.md)
PURPOSE AND CAPABILITIES
Public Land Survey System (PLSS) overlay for ATAK. Draws surveyed township and section boundaries with their labels, the way the built-in Grid Lines overlay draws a computed graticule, and answers "what section is this" for any point on the map.
PLSS is how ground is referenced in the western United States for wildland fire and public-land operations -- division assignments, drop points, contingency lines. ATAK ships MGRS and USNG grid lines but nothing for PLSS.
Capabilities:
- Township and section boundaries as a rendered GL layer, not map items, so the section layer (2.77 million polygons nationally) stays usable.
- Two zoom tiers: townships with their T/R label, then sections with their numbers, each appearing only when large enough to carry its label.
- Toggled from Overlay Manager alongside Grid Lines, and from the plugin pane.
- Color selection per tier: township lines and labels together, section lines and numbers together. The label backdrop flips automatically between dark and light so any chosen color stays readable.
- Go-to-township lookup by principal meridian, township and range.
- Works fully offline once data is installed.
Source data is the BLM National PLSS CadNSDI, which is the authoritative survey record. USGS products derive from it.
A step-by-step user guide with screenshots lives at docs/USER_GUIDE.md in the repository, with the images under docs/screenshots/ (both excluded from the source submission zip).
STATUS
Version 0.5. Verified on ATAK-CIV 5.7.0.5.
Rendering, data pipeline and data management are working and have been exercised on hardware: Samsung Galaxy S21+ (Android 15, ATAK-CIV 5.7) and Samsung Galaxy XCover Pro (ATAK-CIV 5.8.0.3). Labels are placed and sized by ATAK's own label engine and verified through pan, zoom, tier handover and rotation. California, Idaho and Nevada validated against BLM feature counts.
Prepared for tak.gov third-party submission.
POINT OF CONTACTS
Andreas Johansson, takwerx https://github.com/takwerx/plss-grid/issues
PORTS REQUIRED
(This is important for ATO, networking, and other security concerns)
Outbound TCP 443 (HTTPS) only, and only when the operator explicitly requests a data download.
The plugin ships with no map data. On first use the operator opens the data manager, which fetches a small JSON manifest over HTTPS and then downloads the state packs the operator selects. Downloads are resumable and each pack is verified against a SHA-256 digest published in the manifest before it is installed.
No inbound ports. No listening sockets. No traffic to or from the TAK server, and no CoT is generated or consumed. The plugin does not contact the BLM service at runtime -- BLM is queried offline by the tools in tools/ when the data packs are built.
After the packs are installed the plugin makes no network calls at all and functions with the device in airplane mode.
EQUIPMENT REQUIRED
Android device supported by ATAK-CIV 5.6, 5.7 or 5.8. Storage for the data packs the operator installs. Packs are per state and range from about 6 MB to 124 MB; a typical western operating area of three or four states is under 100 MB.
EQUIPMENT SUPPORTED
Any Android device supported by ATAK. No additional or external hardware, no sensors, no peripherals.
COMPILATION
Standard ATAK plugin build. Set sdk.path in local.properties to an unpacked ATAK CIV SDK, then:
./gradlew assembleCivDebug
./gradlew assembleCivRelease
ext.ATAK_VERSION in app/build.gradle selects the ATAK release to target.
tools/ holds the off-device data pipeline (Python 3, standard library only): fetch_blm.py pages the BLM MapServer, pack_plss.py builds the per-state SQLite packs, and make_manifest.py writes the manifest the plugin reads. These are build-time tools and are not part of the plugin.
DEVELOPER NOTES
Data cannot ship inside the APK. The national dataset is about 550 MB across 30 states, which is incompatible with a source submission. The plugin therefore ships bare and downloads packs on request.
The packed store is SQLite with an R-tree spatial index and geometry stored quantized and delta-varint encoded rather than as text. Note that Android's bundled SQLite is built without the R*Tree module: the index is only visible through ATAK's own SQLite, reached via com.atakmap.database.Databases and DatabaseIface. That interface also provides typed parameter binding, which matters because android.database.sqlite passes every argument as text and compares wrongly against the index's REAL columns.
Labels are not drawn by the plugin at all. Every label is registered with ATAK's own label engine (GLMapView.getLabelManager()), which owns placement, screen-size text, decluttering and rotation -- the same engine that places every marker callsign, so labels agree with the surface-drawn grid by construction. Text placed by hand from either render pass does not: the passes do not share a projection, and the error grows with distance from the screen center. Labels must be released back to the engine on every clear and hidden with the layer, or they keep drawing with nothing able to reach them.
The label engine does not render every color faithfully. 0xFFFFA500 text measured (255,231,0) on screen against (255,166,0) for identically colored lines, regardless of bold or priority; ATAK's own palette colors measured exact. Ship palette colors for labels, and measure any hard-coded label color on the device against its line.
Plugin resources must be resolved through the plugin context, while anything that opens a window -- dialogs, popups, list choosers -- must be built with ATAK's Activity context. A Spinner cannot satisfy both, since it inflates with one context and opens its popup with the same one, so pickers here are buttons that open list dialogs.
Zoom thresholds are measured on a device from GLMapView.State.drawMapResolution rather than derived from the scale bar, which changes length to suit round numbers and does not convert to a fixed meters-per-pixel.
PLSS coverage is not universal. The rectangular survey went around Spanish and Mexican land grants, so there is no PLSS beneath much of coastal and southern California. Gaps in those areas are correct, not missing data.
BLM spells some principal meridians more than one way in its own data. The packer canonicalizes them, otherwise the meridian picker offers several near-identical entries and a lookup against the wrong one silently fails.