In the upcoming chapters we will work with remotely sensed imagery. We will mostly process Landsat 8 imagery of the Berlin region downloaded from the U.S. Geological Survey (USGS) EarthExplorer on October, 14 2022. First, you will be given a short introduction into Landsat 8 data products.
Landsat is a joint project of the U.S. Geological Survey and the NASA. The Landsat Earth Observation satellites have continuously acquired images of the Earth's land surface, providing uninterrupted data about natural resources and the environment (USGS 2022). Landsat 8 was launched on February 11, 2013 and comes with a repeat coverage of 16 days (NASA).
Timeline of Landsat Missions, Source: USGS 2016.
Landsat 8 carries two sensors. The Operational Land Imager (OLI) and the Thermal Infrared Sensor (TIRS). Landsat OLI includes the follwoing nine spectral bands (USGS 2018):
Band | Property | Wavelength range (µm) | Spatial Resolution (m) |
---|---|---|---|
1 | Coastal Aerosol | 0.43 - 0.45 | 30 |
2 | Blue (VIS) | 0.450 - 0.51 | 30 |
3 | Green (VIS) | 0.53 - 0.59 | 30 |
4 | Red (VIS) | 0.64 - 0.67 | 30 |
5 | Near-Infrared (nIR) | 0.85 - 0.88 | 30 |
6 | SWIR 1 | 1.57 - 1.65 | 30 |
7 | SWIR 2 | 2.11 - 2.29 | 30 |
8 | Panchromatic (PAN) | 0.50 - 0.68 | 15 |
9 | Cirrus | 1.36 - 1.38 | 30 |
Landsat TIRS comes with t wo spectral bands (USGS 2018):
Band | Property | Wavelength range (µm) | Spatial Resolution (m) |
---|---|---|---|
10 | TIRS 1 | 10.6 - 11.19 | 100 |
11 | TIRS 2 | 11.5 - 12.51 | 100 |
When downloading and working with Landsat Data it is very helpful to understand the file naming convention an the meta data. It will contain information about the sensor, how the data was processed, the acquisition time and how the data is structured. A nice overview about these information is given by USGS or click here for a whole tutorial on Landsat data by Wasser 2021. Here, you will be given only a short overview.
``LXSS_LLLL_PPPRRR_YYYYMMDD_yyyymmdd_CC_TX`
where:
As an example we will explore our Berlin scene:
`LC08_L1TP_193023_20220803_20220806_02_T1`
Means:
Citation
The E-Learning project SOGA-Py was developed at the Department of Earth Sciences by Annette Rudolph, Joachim Krois and Kai Hartmann. You can reach us via mail by soga[at]zedat.fu-berlin.de.
Please cite as follow: Rudolph, A., Krois, J., Hartmann, K. (2023): Statistics and Geodata Analysis using Python (SOGA-Py). Department of Earth Sciences, Freie Universitaet Berlin.