![]() ![]() So you use the dollar sign at the end of your pattern to tell R to only grab files that end with. Note that it is important that the file ends with. In this case, you just want to look at a list of files with the extension. ![]() This allows you to specify a particular pattern that further subsets your data. You can also use list.files() with the pattern argument. To begin, let’s explore your file directory in R, You can use list.files() to grab a list of all files within any directory on your computer. You have already been working with the geotiff file format in this class! You will thus use many of the same functions you used previously, to work with Landsat. This makes it a bit easier to use across many different programs and platforms. In recent years USGS has started to make each band of a Landsat scene available as a. However that format, while extremely efficient, is a bit more challenging to work with. If you look at the Landsat directory for the week_07 data, you will see that each of the individual bands is stored individually as a GeoTIFF rather than being stored as a stacked or layered, multi-band raster.Ĭonventionally Landsat was stored in a file format called HDF - hierarchical data format. ![]() # load spatial packages library ( raster ) library ( rgdal ) library ( rgeos ) # turn off factors options ( stringsAsFactors = FALSE ) Next, you can open the Landsat data in R. There are several links at the bottom of this page that provide tables that help you convert Julian days to actual date. For the purpose of working with Landsat and MODIS data, what you need to know is that the calendar year Julian day represents the numeric day of the year. In class, we won’t spend a lot of time on Julian days. C = OLI & TIRS O = OLI only T = IRS only E = ETM+ T = TM M = MSS.Let’s have a look at one of the files and use the image above to guide us through understanding the file name.įile: LC80340322016205LGN00_sr_band1_crop.tif Sensor Landsat file naming convention Landsat file names Source: USGS Landsat - list.files() to create a subsetted list of file names within a specified directory on your computer.After completing this tutorial, you will be able to: ![]()
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