Frequently Asked Questions
What is OpenSurvey3D?
OpenSurvey3D is a free, MIT-licensed field app for iPhone and iPad. It collects points, lines, areas, routes, media, and georeferenced 3D captures; connects to external GNSS and NTRIP corrections; supports stakeout and check shots; and exports open project files.
Is it really free and open source?
Yes. The app is free, has no required account or subscription, and the native Swift code is published on GitHub under the MIT license. OpenSurvey3D's name and logo remain Laan Labs trademarks, but the code can be inspected, built, and adapted under the license.
Do I need an RTK receiver?
No. The full project and collection workflow runs on the iPhone or iPad location service, typically at roughly 3–5 meter accuracy. That is useful for reconnaissance, inventories, and sketch mapping. An external GNSS or RTK receiver brings the same workflow to sub-meter or centimeter-class work.
Which GNSS receivers work?
OpenSurvey3D connects to supported Emlid Reach RX, RX2, and RS4-generation receivers through iOS Bluetooth ExternalAccessory, and to any receiver that streams NMEA 0183 over a Wi-Fi TCP connection. The TCP path covers hotspot or shared-network workflows used by Emlid RS2/RS2+, Eos, ArduSimple-class, and similar rovers.
Does it include an NTRIP client?
Yes. The app includes saved caster profiles, secure password storage, NTRIP v1/v2 handling, source-table and mountpoint browsing, a directory with list and map views, RTCM forwarding to the connected rover, correction health, and automatic reconnect.
Does it work offline?
Yes. Projects, assets, observations, photos, scans, and generated site models are local to the device. You can download the current 2D map area in advance, and built 3D terrain and imagery stay cached. A network connection is still needed when first downloading map, terrain, or correction data.
What can I import and export?
Import points, lines, routes, and areas from CSV, GeoJSON, GPX, and KML, including projected northing/easting when the project coordinate system is set. Export CSV, GeoJSON, DXF R12, LandXML 1.2, a complete project ZIP, QA reports as PDF or HTML, and terrain geometry as OBJ.
What 3D capture does the app support?
OpenSurvey3D has LiDAR mesh, LiDAR point-cloud, and photogrammetry capture paths, plus ordinary photos and video. Captures can be anchored to a surveyed asset and observation, viewed in the project, included in QA, and combined with terrain, imagery, routes, and points in a 3D site model. Device capabilities vary; LiDAR modes require LiDAR hardware.
How does AR asset finding work?
Choose Find in AR from an asset or open a browsed project to see its nearby assets through the camera. OpenSurvey3D converts stored project coordinates into local AR pins and shows target direction, bearing, and distance for assets within 250 metres. The view inherits current GNSS and compass uncertainty, so it is designed to reach an asset's vicinity. Use numeric stakeout and check shots when a position must be set or accepted.
How does field QA work?
Every observation keeps its positioning pedigree and receiver health. For independent verification, re-observe an imported design point or collected control point. The app records northing, easting, and vertical residuals, tolerance and pass/fail, and project RMS, then produces a report with checks, estimates, solution health, captures, and exceptions.
Which coordinate systems are supported?
Projects can use WGS 84 or select from 325 NAD83 State Plane and worldwide UTM entries. Projected imports and exports carry easting, northing, units, and EPSG identity where available. The app keeps geographic and projected coordinates together instead of discarding one representation.
Is the browser workspace available?
Not yet. The native iPhone/iPad app, local projects, open-source repository, and file-based handoff are available now. A synced browser workspace and self-hosted team backend remain on the roadmap.
Is this a replacement for a licensed surveyor?
No. OpenSurvey3D is a measurement and documentation tool. Boundary determination and many survey deliverables legally require a licensed professional. The app preserves measurement context and quality evidence; it does not make professional or legal judgments.