Tutorial

Install InsarViz

To install the InsarViz tool, please follow the installation instructions.

Launch InsarViz

Once InsarViz is correctly installed, first make sure that you are in the virtual environment used during installation, and then simply use the command:

ts_viz

If you want to launch the tool directly with a data file or an insarviz project opened, then use the -i option:

ts_viz -i /path/to/my/data_or_project_file

Main window

The main window that opens up when you launch the tool is divided into three vertical columns:

On the left, from top to bottom, you will find the Layer panel and the Minimap sub-window.
In the center, the Band slider and the main Map.
On the right, the Colormap panel.

The Layer panel shows the layers, their order and their properties.
The Minimap is a full-extent view of the map with a white rectangle marking the area currently displayed in the Map, only the Main Data Layer is displayed. It can be detached from the main window or closed. Check the menu View > Minimap to show it again after you have closed it.
The Band slider allows you to navigate in the temporal dimension of the dataset, either by setting a band number directly or using the slider to navigate between bands. When available in metadata, the dates corresponding to the bands are shown on an interactive timeline under the band slider.
The Map is where the current layers are displayed.
The Colormap panel is where you control the colormap for the main data layer.

Load data

You can load data using the menu File > Open datacube or project (see Supported formats).

When a dataset is loaded for the first time, the histogram of every band is computed. This can take some time (up to a few minutes on a large dataset). If you save your work inside an InsarViz project using the menu File > Save project, the histograms are saved within the project and thus won’t be recomputed again when you reopen it. Loading time is shown in the Terminal.

Note on performance: the dataset is loaded dynamically, as you navigate through the bands, new bands are loaded and rendered. Only the rendering image is stored for later display, the data itself is not stored as this would dramatically reduce performance.

Colormap

The Colormap panel is used to control the color rendering of the Main Data Layer in the Map and the Minimap.

On the left, the histograms show the distribution of the data values. The blue histogram represents all the bands (the whole dataset), while the red histogram represents the current band. Histograms can be hidden by left-clicking on their color in the bottom legend. You can scroll or right-click + drag to zoom in/out on the histograms.

The colorbar on the right shows the current colormap, which can be changed through right-click.

The area in blue on the histograms shows the mapping of the colormap on the data distribution. You can move this area and change its boundaries using left-click + drag.

On the top of the Colormap panel are three buttons:

Autorange all bands change the mapping of the colormap to cover the range between the 2th percentile and the 98th percentile of all bands (the whole dataset).
Autorange current band change the mapping of the colormap to cover the range between the 2th percentile and the 98th percentile of the current band.

Navigate through space and time

In the Map and Minimap, you can:

Click + Drag to move spatially around.
Scroll to zoom in/out.
Ctrl + Scroll to rotate the z=0 plane
Shift + Scroll to Incline the z=0 plane

To navigate in the temporal dimension, use the Band Slider at the top of the Map, or the left/right arrow keys. When available in the file metadata, (see Supported formats), an interactive timeline is also displayed. You can also sepcify a reference band that will be substracted to every other band.

When you hover over the Map, information on the point currently under the mouse cursor (coordinates and value) are displayed in the footer of the window and in the cursor tooltip.

Nodata or NaN points are not rendered, they appear in the same: color as the background.

You can flip the Map vertically or horizontally using the menu View > Flip Vertically or View > Flip Horizontally.

Since InSAR data usually represents a height displacement, you can also use 1-band DEM layers’ and/or datasets’ values as height for a 3D rendering of your surface’s topography, by tweaking the DEM scale parameter.

Plot curves

Plot windows

Select the menu View > Plotting to dislay the plotting windows (or Ctrl+P). This opens two new tabbed windows on the right of the main window: the Temporal Profile window and the Spatial Profile window. Those windows can be detached from the main window or closed. Check the menu View > Plotting again to show them back after you have closed them.

In the Temporal Profile window, plots are displacement versus time. The thick vertical line in the Temporal Profile window marks the band/date currently displayed, and can be used to change the current band/date (left-click + drag).
In the Spatial Profile window, plots are displacement versus distance on the Map.

As you hover the cursor over the Map, a temporal profile of the point under the cursor is interactively drawn in the Temporal Profile window (thick red line). This mode enables rapid, dynamic exploration of the whole dataset.

In the Spatial Profile window, you can also choose to view a profile in 3D, along both the time and space axes. A yellow line shows the current band, and the magenta line highlights the time series of the profile’s focus point.

In the Temporal Profile view, you can perform some basic curve fitting to assess the behaviour of a time series (either from a Point, or from a profile’s Focus Point).

Selection tools

While moving around in the map, you can also define shapes and compute their temporal profiles.

There are two kinds of shape that can be created : Points (with Ctrl + drag) and Profiles (with Shift + drag)

Points are circles that are created with a center and a radius. Their temporal profile is the spatial mean of all pixels within the circle.

Once created, a Point has a radius that can be modified in the Layer Panel, its name and color can also be modified there (double-left-click on the field you want to modify).

Profiles define a series of points along a line (or a broken line), with a focus point, which is a special point of interest on the profile.

When creating a Profile, start by holding Shift, and drag the first segment, then release and hold the mouse for the second segment, and so on. When done, release the Shift key, and the profile will be added to the Profiles list.

Once created, you can adjust the Profile’s radius, color and name in the Layer Panel, just like a Point. You can also adjust its focus, which is the center of the focus point along the profile.

The temporal profile of each point along the line (or the temporal profile of the mean of each point’s surface if the Profile has a radius > 1) can be displayed in the Temporal Profile window, a circle is displayed around the current focus center.

Likewise, the spatial profile of the Profile can be displayed in the Spatial Profile window, for the current band. An interactive vertical line represents the current focus for that profile.

When a Profile has a radius > 1, each point of the line is like a Point with the same radius, thus the value of this point is the spatial mean of the square centered on this point with the same radius.

Plot options

The plots are zoomable with scroll or right-click+drag. To go back to the full view, you can right-click > View all. You can also adjust each axis limits manually by left-click + dragging or scroll on it, or right-click > X-Axis / Y-Axis. Once you are satisfied with the axes settings, you can lock them using the Lock axes checkable box on the top of the window. You can also show/hide grids and access other axes options (log, invert…) through right-click > Plot Options.
To export the plot click the Export… button or use right-click > Export.

Add layers

Select the menu Layer > New … to add a new Layer. For now, there are three types of layers you can add in InsarViz:

If you select Layer > New Raster1B, you can add a single band of a raster file. If your data are georeferenced, any georeferenced raster file can be added. If your data are not georeferenced, the added raster file must have the same shape as your data. You can change the colormap of this in the Layer panel.
If you select Layer > New RasterRGB, you can add three bands of a raster file as an RGB image. If your data are georeferenced, any georeferenced raster file can be added. If your data are not georeferenced, the added raster file must have the same shape as your data.
If you selected Layer > New Swipe Layer, you can add a Swipe Layer, which can hide the layers above it beyond a given threshold

A layer can be hidden by clicking on its checkbox in the Layer panel. A layer as an alpha (transparency) value between 1 and 0, that can be changed in the Layer panel. Layers order can be changed by dragging them up above or below one another.

Background Maps

If your data is georeferenced, InsarViz will automatically display a background map, retrieved from a standard map provider. You can choose a provider in the bottom menu of the Layer Panel (it is “OpenStreetMap” by default, but there are a few others).