Geospatial data visualization

Overview

The UP42 platform does not support the direct visualization of geospatial assets and job outputs. Download and render them in third-party GIS software.

Step 1. Download and examine files

Step 2. Open assets in QGIS

Step 3. Add basemaps

Step 1. Download and examine files

Download tasking or catalog assets, or job outputs.

The unpacked folders will contain different file formats depending on the source of the data. Find the file you will visualize by analyzing the folder structure:

• DIMAP folder structure

  This folder structure is used for Pléiades and SPOT collections. It consists of several folders with different prefixes:

  • _MS_ for analytic multispectral assets
  • _P_ for analytic panchromatic assets
  • _PMS_ for display assets

  For visualization, use corresponding XML files with DIM_ prefixes inside these folders instead of TIF or JPEG files, because they may be not georeferenced.

• Simple folder structure with GeoTIFFs

  If the unpacked folder has a simple structure, use TIF files. GeoTIFF is the most common geospatial data file format, a single file that contains one or multiple color bands. Some TIF files are also cloud optimized (COG).

Step 2. Open assets in QGIS

1. Download and install free open-source software QGIS.
2. Drag and drop the required file (XML or TIF depending on the source) into a QGIS project.

For more information on how to use QGIS, see QGIS documentation.

Step 3. Add basemaps

Optionally, you can use different basemaps as location references for your image in QGIS.

1. In the top navigation menu, click Plugins → Manage and Install Plugins.
2. Search for QuickMapServices. Select it and click Install Plugin.
3. In the top navigation menu, click Web →  QuickMapServices → Settings.
4. Go to More services and click Get contributed packages.
5. Click  QuickMapServices and select a basemap of your choice.

Pansharpen images

You can also use QGIS to pansharpen analytic data products from Pléiades and SPOT collections. There are different ways to do it, and one of the easiest is to use a pansharpening tool by GDAL.

1. In QGIS, click Processing → Toolbox to open the toolbox sidebar.
2. Import necessary assets:
   • An analytic multispectral asset with the _MS_ prefix
   • An analytic panchromatic asset with the _P_ prefix
3. In the toolbox search bar, search for GDAL → Pansharpening and select it.
4. Choose the _MS_ image as the Spectral dataset and the _P_ image as the Panchromatic dataset.
5. Click Run.

The pansharpened image will be displayed as a new layer in your QGIS project.

Video tutorials

How to download and visualize job outputs

Troubleshooting

My image appears colorless, bland, or half transparent

Sometimes QGIS interprets the near-infrared band as the alpha band. The optional alpha band in RGB images is used for giving transparency to specific parts of the image.

1. In QGIS, right-click the image layer and click Properties.
2. Go to Transparency.
3. Under Custom transparency options, select None instead of an image band. Click Apply.

My image has a lot of white spots where there should be pixels

Sometimes in products of the display radiometric processing level, the nodata value is set to 0. At the same time, some very dark pixels are also set to 0. This causes this white spot effect.

1. In QGIS, right-click the image layer and click Properties.
2. Go to Transparency.
3. Under No Data Value, clear the No data value checkbox. Click Apply.

My image is too dark or too bright

There isn't a default setting for images. Manually change different option values to achieve a satisfactory look.

1. In QGIS, right-click the image layer and click Properties.
2. Go to Symbology.
3. Under Band rendering, go to Contrast enhancement and select Stretch to MinMax.
4. Expand the Min/Max Value Settings drop-down pane.
5. Try changing values for Cumulative count cut and Mean standard deviation. Click Apply after each iteration to see the result.

My Pléiades or SPOT images are rotated 90° counterclockwise

You rendered a JPEG file instead of an XML file with a DIM_ prefix. For more information about the DIMAP format, see Pléiades and SPOT 6/ 7 Format Delivery.