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.
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.7.0.2 -- 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.
V. 7.0.1 --24 March 2026
• FIXED -- A bug that would cause crashing immediately after install of v. 7.0.0 in some unusual circumstances.
• FIXED -- A bug that would cause the map overlay transparency slider on the Map Screen to disappear when it was set to 100% transparency and the user temporarily left the Map Screen (e.g., when entering an orientation or POI. The slide will now be there when you go back to the Map Screen.
v. 7.0.0 -- 21 March 2026
• NEW -- Calculate the slip magnitude on a fault given the orientation of the slip vector (from slickensides, mylonitic lineations, etc.) and any two points on a planar contact that has been offset by the fault. For the calculation to be accurate, it requires that the offset plane have the same orientation on either side of the fault. To do this calculation, first measure the lineation on the fault plane. Tap the lineation and then select "Displ. from Separation". You will then need to type in the orientation of the offset plane. Then tap on the contact on the map on one side of the fault, and then again on the same contact on the other side of the fault. As you tap and drag along the 2nd contact, the slip is displayed next to the pointer hotpoint. When you lift the pointer, the slip will be displayed in a message box and it will also be written to the notes field of the lineation on the fault plane. Interestingly enough, entering the strike and dip of the fault plane is not necessary for this calculation! Also, the intersection of the fault plane with the contact does not need to be exposed anywhere.
NEW -- You can now specify the font size by observation type so, for example, the labels for fossil sample POIs can be a different size than formation type POIs, etc. The same is true for orientation and contact types. You set the font size by going to the Settings Screen (gear icon), tap Edit Data Types & Tags, select the POI, Orientation, or Contact type to Edit, then tap the Edit button and in the Edit Type screen, enter the Font Size. Following the same path, you can use the switch next to the Font Size label to toggle on or off whether labels are shown on the map for that type. Thus, you can opt to show contact names for stratigraphic type contacts but not for, say, access roads.
FIXED -- A few more, mostly minor bugs were squashed.
