Sparrow - geospatial data visualization

The Sparrow application provides a virtual globe to visualize earthquake hypocenters, earthquake source models, fault traces, topography datasets and other geoyhisical datasets in 3D and over time. Its primary focus is on simplicity, allowing for interactive dataset exploration and export of short animations for scientific presentations.

Note

The Sparrow is currently in an experimental stage. Bugs and errors might occur during its use and some essential features might still be missing.

Please help us by providing feedback through Issues, Discussion, or Coding.

Requirements

• The Sparrow has one additional requirement which (on purpose) is not listed as a hard requirement for the rest of Pyrocko: VTK. Please install it with your installation method of choice (e.g. on Deb based Linuxes, use apt install python3-vtk, in an pip-managed environment use pip install vtk, or under Anaconda/Miniconda use conda install vtk). Sparrow will complain if VTK cannot be found on startup.

• Make sure your graphics card driver setup allows for hardware-accelerated OpenGL (e.g. check with glxinfo -B, look for OpenGL renderer). If you have an NVIDIA graphics card, you may want to install their proprietary drivers.

• For visualization of InSAR scenes, Kite is needed.

Invocation

Run sparrow from the command line to launch into Sparrow’s graphical user interface (GUI). To get a list of its options, run sparrow --help.

Figure 1: Startup state of the Squirrel GUI, with Icosphere, Grid and Coastline elements

First flaps

Online help

Instructions and help are shown in the status bar at the bottom of the window.

Navigation

There are two navigation modes, global and fixed. In global navigation mode the location of the focal point is changed when you click and drag the mouse, in fixed navigation mode, the location is fixed and the view angle is changed when you click and drag. Navigate to a point of interest in global mode and then click “Fix” in the navigation panel to investigate your target. You can also hold down the control key to toggle between the navigation modes.

The focus point is visually shown when “Crosshair” in the navigation panel is checked.

The depth of the focal point can be set by modifying the third value [km] in the “Location” field. Use negative values to set the focal point into the atmosphere.

Elements

The scene shown in the view is composed of so-called elements. By default the Icosphere, Grid and Coastline elements are shown. You can add more elements using the “Add” menu. Elements can be shown/hidden by clicking on the pentagon sym