Stereogram Go is a field data collection application for structural geology. It records the orientation of planar and linear features using the sensors built into a phone, organizes those measurements by station and sample, attaches photographs and notes, and functions without a network connection. Data collected in the field is later synchronized with Stereogram Pro, the companion web application, for analysis.

Measurement of orientation:
Planar features such as bedding, cleavage, foliation, joints, veins and fault surfaces are measured by placing the phone flat against the surface. Strike, dip and dip direction are computed from the device accelerometer and magnetometer. Linear features, including fold axes, mineral lineations and slickenlines, are recorded as trend and plunge, or as a rake on the host plane. Measurements may be entered and displayed in right-hand-rule strike, dip direction or quadrant notation, following whichever convention the user was trained in. Each measurement carries a feature type and any project-specific attributes the user has defined.

Stations, samples and photographs:
Observations are grouped by station. The station position is taken from the GPS receiver and can be adjusted on the map where the fix is unreliable. Samples are recorded with their formation, purpose and any custom fields required by the project. Photographs of the outcrop are stored with their compass bearing and position, so that each image can later be related to the measurements taken at the same locality. Photographs are held in the user's own Google Drive rather than on our servers. Field notes may be dictated and transcribed to text.

Review in the field:
A stereographic projection of the current project is available at all times, allowing the distribution of poles and lineations to be inspected while still at the outcrop and an erroneous reading to be repeated before leaving the site. The map view displays every station and orientation symbol in the project over an offline base map, with optional user-supplied overlays. A tabular view lists every record and permits editing.

Working offline and with Stereogram Pro:
The application does not require a connection to record data; synchronization takes place when one is available. A project may contain any number of formations, feature types and stations. Users sign in with an email address, a Google account or an Apple ID, and the same projects are then available in Stereogram Pro in a web browser for stereonet analysis, density contouring, rose diagrams and export.

Stereogram Go is free to use for data collection. Synchronization with, and analysis in, Stereogram Pro requires a Stereogram Pro subscription, which is purchased separately on the web and is not offered within this application.

Stereogram is developed by geologists at Sigma Geoscience. The field manual is available at https://sigmageoscience.com/go-manual and the privacy policy at https://sigmageoscience.com/privacy.