Task: Download three Landsat 8 satellite data for the dates 24 May 2019, 27 July 2019 and 28 August 2019 covering our case study area - Miandoab irrigation scheme.

The Landsat program is the longest-running program for acquisition of satellite images of Earth (USGS/NASA project). Landsat 1 was launched in July 1972 and the most recent satellite (Landsat 8) was launched in February 2013, Landsat 9 is expected to be launched in January 2021. Landsat 8 has two instruments on board: the Operational Land Imager (OLI) for optical bands and the Thermal Infrared Sensors (TIRS) for thermal bands. Optical bands of Landsat 8 imageries have a spatial resolution of 30 m and a revisit time of 16 days.

The main archive of Landsat satellite (all missions – TM/ETM/OLI) is earth explorer website.

Step 1:

First step is to create user login for this website so that you are able to download the data.

Let us now search and download data for Miandoab irrigation System (see Figure 1) for the time period January to December 2019.

Figure 1: Location of the Miandoab Irrigation scheme and Landsat tile covering the scheme

Step 2:

In the “Search Criteria”, under the “Geocoder” card, select your “Path/Row” - 168/034 as Geocoding Method.

Click on the result (red box) and a location popup will appear over on the map on the right panel.

Figure 2: Setting the search criteria

Step 3:

Now enter the date range for which data is required in the same tab.

Figure 3: Setting the date range

Step 4:

Select the datasets you want to search and set the additional criteria of those data with cloud cover less than 20%.

Here we are selecting only Landsat 8 data. For previous years you can also try with Landsat 7 ETM, and Landsat 4/5 TM. Finally click the “Results” to see list of all available data with our conditions met for the study area in the given period of time.

Figure 4: Setting additional criteria and listing results

An explanation on different levels and collections of Landsat data is given here.

Step 5:

Check the listed scenes using browse images, select and download only the 168/034 scene.

Figure 5: List of available Landsat 8 data for the given period of time.

The image icon under each result can be used to see the preview of that Landsat scene (see Figure 5). The download icon can be used to download that single scene without ordering. While the Bulk download icon can be used to get a single link to download multiple products at a time. More details on bulk download can be found in these links –[link1], [link2]-

Figure 6: Preview image of a Landsat scene

Now that the image dated 24 May 2019 looks really good, click on the download icon to get the data. You have to login in order to download the data.

Figure 7: Landsat download options, select the one highlighted

From the list of options download the “Level-1 GeoTIFF Data Product” to get all the spectral bands and metadata of the scene. Please note the file size: about 900 MB (make sure your internet connection is stable and foresee sufficient time for download).

Similarly download the L8 data dated 27 July 2019 and 28 August 2019.