Hexagon Geospatial
MENU

Spatial Modeler Tutorials

Learn more about our products, find answers, get the latest updates, and connect with other Hexagon Geospatial product users, or get support from our professional service team.
Showing results for 
Search instead for 
Do you mean 

Download Landsat 8 scene and Stack MSI image

by Technical Evangelist on ‎04-12-2018 09:30 AM (644 Views)

 

Download Model

 

Description

 

This Spatial Recipe is pretty self-explanatory. It uses the new Get AWS Landsat 8 Scenes operator to connect to an Amazon Web Service S3 Bucket, downloads one or more Landsat 8 scenes (which consist of individual GeoTIFF files per Band) of the desired location and stacks bands 1 to 7 into a Multispectral output layer stack. The original TIFF files (such as the Pan band, B8) also remain available. 

 

Please note that this operator relies on an external service not owned or controlled by Hexagon Geospatial. The bucket is provided by Amazon Web Services, Inc. and the data by USGS. If the service is discontinued or the site moved, the operator may cease to function. It is highly recommended that you review the following web page prior to using this operator. I.e. don't specify a Boundary Input that covers the whole Earth - that way leads to getting your IP address blocked by Amazon.

 

https://aws.amazon.com/public-datasets/landsat/

 

getlandsat8scenes_v16_5_0.gmdx
L8_Main_Model.PNG
 
List Iterator sub-model:
L8_List_Iterator.PNG
 
Band Iterator sub-model:
L8_Band_Iterator.PNG
 

 

Data Requirements

 

Before you attempt to run the model open a 2D View and load some data which covers the area of interest. Right-click in the 2D View and select Inquire Box and drag the box to cover the geospatial extent you want to search for available Landsat 8 images. Leave the Inquire Box dialog open and Run the Spatial Model. In the Run dialog use the ... button on the Search Extent to bring up a Boundary dialog that let's you click From Inquire Box to grab the appropriate extent.

 

The service request will return all scenes which touch that bounding box, so don't make it too large!

 

Setting the search extent:
L8_Extent.PNG

 

Each scene will download into a separate sub-directory of the Download Directory specified when running the model. The sub-directory name will be used as the base for the name of the stacked multispectral image (with _msi.img appended) and that MSI image will also be added to the appropriate sub-directory.

 

If the requested scene has already been downloaded (to the Download Directory) it will not be downloaded again, nor will any existing TIFF files be stacked if they haven't already been.

 

The Get AWS Landsat 8 Scenes operator has been set to retrieve the "Most recently acquired" scenes. This can be altered in the model to retrieve the scene with the "Least amount of cloud cover" instead. Ascending mode (i.e. nighttime) images can also be requested.

Courses
Contributors