GMDE Lite
iOS Universel / Education
GMDE Lite has been designed from the ground up with small phone-sized screens in mind although it also works very well on iPads and spectacularly on iPads with an Apple Pencil. We borrow the best from both GMDE Mobile and Stereonet Mobile and present that functionality in a clean, simple, map-centric interface. Data can be exchanged between GMDE Lite and Desktop, and imported from Stereonet Mobile, GIS programs, as well as uploaded or downloaded to/from StraboSpot.
Some things GMDE Lite can do:
• Set a point of interest (POI) at your current location or anywhere on the map which is immediately tagged with location time and date and to which you can attach a photo and an extended description. You can email a POI, complete with photo, to a field partner, Advisor, etc.
• Annotate photos or make digital sketches attached to points of interest.
• Enter an orientation by any of six methods: (1) using the device orientation, (2) tapping 3 points on the map and having the device calculate the orientation, (3) sighting along the contact plane either in the strike or dip direction, (4) best fit plane to selected vertices on a path, or (5) type typing in the orientation at the location that you specify. You can project a contact temporarily as a check on the validity of the orientation; the projected contact can be converted to a regular contact.
• Read in and display POIs, orientations, and contacts on the map data from Stereonet Mobile or GMDE Desktop. Use copy and paste between devices registered to the same Apple ID using Apple HandOff technology.
• Enter contacts by tapping and dragging a path, by recording a GPS track, or by projecting a planar orientation across the landscape. Edit contacts by lassoing and deleting vertices or tapping and dragging individual vertices (works way better on an iPad with Apple Pencil than it does with your finger on a relatively tiny iPhone screen).
• Use the device camera/orientation as a rangefinder and plot a point of interest at the sighted location. Rapidly use the rangefinder to determine azimuth, inclination, slope, horizontal, and vertical distance to the sighted location.
• Display orientation data on an equal area, lower hemisphere projection which can be filtered by data type. Mean vectors, cylindrical best fits, poles to planes, and rose diagrams can be displayed.
• If you have a data connection, GMDE Lite can display your data on Apple Maps within the program as well as get point elevations from an online server.
• Use a variety of icons and colors to represent different types of data.
• Access all of your data on your device from, and upload to and download from, the Files app on the device. Upload to and download from StraboSpot. Copy and paste between GMDE Lite and Stereonet Mobile.
Skills you need to take full advantage of GMDE Lite:
GMDE Lite can be used "right out of the box" with a cellular data connection using an online satellite or road base map, and online elevation server, in 2D to measure and collect strikes and dips, plot contacts, do 3-pt problems, etc. To experience the full power of GMDE Lite, and for complete offline operation (essential in remote field areas), you will need to know how to do the following:
• Produce base maps from whatever source you want in MBTiles format. Because you are producing your own base maps you can use whatever you want (existing geologic maps, USGS Topo Maps, LiDAR hill shade images, etc.) and not just the few option available from online mapping companies. Maps can be produced with my free desktop program MBTileMakerViewer.
• Download and format digital elevation models (DEMs) in GridFloat or BIL format. Having a DEM on the device is what allows GMDE Lite to perform its magic such as calculating an orientation from three points. DEMs can be produced with my free program DEM Masher (requires GDAL).
• Know enough about your digital devices to understand how to move files onto or off the device from/to your desktop computer.
Quoi de neuf dans la dernière version ?
v. 7.2.0 -- 2 June 2026
• NEW -- The rangefinder now has an option to measure vertical angles only. If you know your horizontal distance to the outcrop, the app can calculate thickness of horizontal units in a cliff face (or measure the height of a treen, etc.). Just set the lower angle to the base of the unit and the upper angle to the top of the unit. There are lots of other potential uses for this function.
• NEW -- When measuring a strike and dip with the device orientation, a green line will appear from topo to bottom on the stereonet face when the long axis of the phone is horizontal. An arrowhead on one end of the line shows the physical direction of the given strike direction. Explanation: Because the app measured the pole to the plane directly, you can place the phone on the bedding surface in any orientation. But, sometimes, you want to know where the strike line is (e.g., when collecting and marking an oriented sample). This allows you to find the actually strike line in the plane as well as determine which direction you should mark the sample so that it coincides with the measured strike line.
• FIXED -- Switching between base maps now works more smoothly without showing a blank white screen.
v. 7.1.0 -- 11 May 2026
• NEW -- Subsampling and smoothing contacts are now undoable. Just give your device a shake within 2 minutes of applying the subsampling or smoothing, and the old contact will be restored. Subsampling now uses the Ramer-Douglas-Peucker (RDP) algorithm for better results. The degree of subsampling can now be set with a slider control. As you move the slider, the number of vertices to be deleted will appear above the slider.
• NEW -- Additional database integrity checks are now in place. The checks are carried out every time you open a database. If corruption is found, the problematic rows are reported.
• NEW -- If the app experiences a hard crash (with no error message), the next time you start up the app, it will warn you of an abnormal exit and will inform you that it is starting up without opening up the last database used (just in case). You’ll need to open the database by going to the settings screen and tapping Open Project. With the new database integrity check, if the DB causes the problem, you will be informed when you try to open it. If the problem is with the tiny resume file, that will be rewritten when you open the database. This way, the app will remain operable, and you can troubleshoot the problem more effectively rather than continuing to crash repeatedly with no message and no recourse.
V.7.0.2 -- 13 April 2026
• NEW -- Correction for camera bump on the back of modern phones. Modern iPhones and iPads have bumps or plateaus on the back to accommodate more powerful cameras, and rugged cases can make the back of the phone even more irregular. This means the back is no longer flat, which can impact measuring of strikes and dips by placing the device on the bedding or fault surface. This version can correct for that non-planarity: Go to the Settings Screen (gear icon) and tap the new option "Correction for Camera bump." You will be taken to a new screen entitled Camera Bump Correction. Follow the instructions on the screen to set the correction factors. You can also use this screen to reset the correction factors to zero. Once set, these corrections will be applied whenever you measure the orientation by placing your device on the outcrop and will remain active even when you change projects. An incorrectly applied correction (e.g., not following the instructions) can thoroughly mess up your measurements!! You'll see from the displayed pitch and roll angles that the corrections are typically small, but more accurate is always better!
• IMPROVED -- Outline text has been made more legible by a slight increase in the spacing between letters.
• FIXED -- A bug that prevented the reading of some newly saved newly saved contact type characteristics. Other bugs fixed as well.
