Case Study on Multispectral Land Cover Classification - Open Source Geospatial Tools: Applications in Earth Observation - page 287

data (Sect. 17.1 ), create training data (Sect. 17.2 ) and classify image (Sect. 17.3 ). The
fourth deals with the accuracy assessment of the resulting map (Sect. 17.3.4 ). Most
of the workflow is fully automatic. The two exceptions, represented by the boxes in
gray, require manual intervention for the labeling. The first is related to the labelling
of clusters identified by the unsupervised classifier. The second is related to the inde-
pendent test set necessary for the accuracy assessment. The approach followed here
is to do the labeling using photo-interpretation of independent high spatial resolution
imagery. Alternatively, a subset of the training dataset could also be used.

17.1 Create Input Data

The workflow presented in Fig. 17.1 starts by creating the input data for the clas-
sifier. In this instance we use the two Landsat 8 scenes that were downloaded from
the USGS corresponding to path 207 and row 23 and acquired in 2013 (see also
Appendix A.2.2).

• LC82070232013160LGN00.tar.gz (2013-06-09)

• LC82070232013192LGN00.tar.gz (2013-07-11).

The archived scenes contain data that have been processedwith the Level 1 Product
Generation System (LPGS) software (version 2.2.2). Each archive contains 13 files:
•

11 raster datasets for the multispectral bands ( B1-B11 );

•

One quality assessment raster dataset ( BQA );

• One metadata file ASCII file ( MTL ).

The archive files are compressed and need to be unpacked. In a Linux environment,
this can be done using the tar command, with the options x (extract), z (unzip), v
(verbose) and f (from archive file). In Windows you can use WinZip or 7Zip.

tar xzvf LC82070232013160LGN00.tar.gz

-rw-rw-r-- lpgsops/prodgen 118183658 2013-06-09 17:42
ₒ LC82070232013160LGN00_B1.TIF
-rw-rw-r-- lpgsops/prodgen 118183658 2013-06-09 17:42
ₒ LC82070232013160LGN00_B2.TIF
-rw-rw-r-- lpgsops/prodgen 118183658 2013-06-09 17:42
ₒ LC82070232013160LGN00_B3.TIF
-rw-rw-r-- lpgsops/prodgen 118183658 2013-06-09 17:42
ₒ LC82070232013160LGN00_B4.TIF
-rw-rw-r-- lpgsops/prodgen 118183658 2013-06-09 17:42
ₒ LC82070232013160LGN00_B5.TIF
-rw-rw-r-- lpgsops/prodgen 118183658 2013-06-09 17:42
ₒ LC82070232013160LGN00_B6.TIF
-rw-rw-r-- lpgsops/prodgen 118183658 2013-06-09 17:42
ₒ LC82070232013160LGN00_B7.TIF
-rw-rw-r-- lpgsops/prodgen 472550958 2013-06-09 17:42
ₒ LC82070232013160LGN00_B8.TIF