Working with Landsat imagery in ArcGIS Pro

in this video we'll show you how to access download and work with Landsat imagery using ArcGIS Pro we're starting out in glovies which is the USGS global visualization viewer globe is a wonderful online tool that allows you to search different USGS datasets apply search criteria and easily download these data so you can bring them into your GIS for further analysis Clovis makes it really easy to access the data you want you simply pan or zoom to the location select the datasets apply any search criteria you want and you can download that data directly from glovies to your computer I'm interested in obtaining a Landsat scene over the presidential range in New Hampshire so I'm going to use the jump tool to enter the latitude and longitude coordinates for Mount Washington which is New Hampshire's highest peak and then just zoom in a little bit over on the left for choose your datasets I'm going to turn on the radio button for Landsat 8 oli as soon as I do this globe is begins displaying some Landsat scenes I can browse through those scenes this would take a long time and there's an awful lot of scenes with a tremendous amount of cloud cover to improve my search I'm going to go over to the metadata filter and constrain my search to only those scenes with 0 to 20 percent cloud cover and those acquired in the months of June July and August now I'm able to browse through the collection of Landsat 8 scenes that meet my search criteria I have the ability to exclude certain scenes from my browse by clicking on the hide scene button this is useful because I clearly have some Landsat scenes in this case that have extensive clouds over the presidential range the whole scene may not be cloudy but the area around the presidential range is so I'm going to hide those scenes if any time I want to show those scenes again I can go back to the choose your datasets and click on clear hidden scenes for any scene I can move over and click on the view metadata button to obtain all the information about that scene this will include everything from the percent cloud cover to the acquisition date to even specific sensor parameters that I may want to use for calibration once I found the Landsat scene that I'm interested in I simply move over and click on download' glovies will package up the Landsat scene I want to make sure that I click the download button for the level 1 geo TIFF product as this is the full Landsat 8 data set once the download is ready I'll save the tar.gz file to my computer where I can uncompress it and make use of the Landsat data you may need a specialized zip utility to uncompress the tar.gz file that glovies uses to package up your landsat data I recommend 7-zip here I'm going to first uncompress the GZ file then unpack the tar file once the data uncompressed separate Landsat band his stored is its own individual geo TIFF file in addition to the individual Geo tube band files I also have some metadata and calibration files that may be useful to me the metadata stored in the underscore MDL file opening up will allow me to read through the metadata and access key information particular things like the date the scene was acquired on the bathro cloud cover and calibration parameters although it's certainly possible to add each individual band and work with it separately within ArcGIS what I really want to do is combine all these bands together into a single multi spectral composite image to stack the bands that I'm interested in working with into a single multi band raster data file I'm going to use the composite bands to your processing tool the composite bands geoprocessing tool will produce a new raster file containing all of the bands that I enter into the composite bands tool my input raster's are going to be all the bands that I'm interested in in my case I'd like to load in bands 1 through 7 these are the 30-meter multispectral bands that are commonly used in a multi band raster data stack once I have these raster selected it's imperative that I pay attention to their order in the composite bands tool the order they're listed in the composite bands tool determines their band order within the multi band raster output in this case you can see the band one is accidentally at the bottom so I'm going to need to reorder the bands by moving band one up to the top so that it becomes layer one in the resulting output raster dataset I'm going to save my composite raster as a geo TIFF file by navigating to the directory that I want to store it and typing dot gif at the end of the file extension distort is imagined format I would replace the del T if' without IMG or alternatively I could save it inside a geo database running the composite bands tool stacks all of these raster's into a new single composite band raster file and in my case I've stored it in JIRA TIFF format once the composite bands tools finish running it's important to go into the properties of my new layer to confirm that the tool ran is expected by going into the source tab and raster information I can access the key source information about this data set specifically I want to check the number of bands which is seven I see that the cell size is 30 by 30 which is the resolution of these particular Landsat 8 bands the format is geo TIFF and the pixel depth is 16-bit just as I expected the best way to adjust your symbology for imagery is to move over to the appearance tab and go to bang combinations you can see the dark jazz already has two defaults natural color and color infrared unfortunately these band combinations are for aerial imagery not for Landsat 8 imagery under the appearance tab I'm going to get accustomed and I'm going to create custom bank combination settings for some common Landsat a bank combinations 3 2 1 4 3 2 etc until I have all the bank combination set this will allow me to quickly and easily symbolize my Landsat 8 multi band composite image now that I have my bank combination said I can make some other changes to the appearance of my imagery activating DRA or dynamic range adjusts automatically modifies the contrast stretch within my field of view as I pan around the image you may find that certain stretch types help you pick out particular features of interest but it's important to keep in mind that there may not be one single stretch type that's optimized for all the features you're interested in on the landscape remote sensing is an autonomous science to toning the best symbology takes a bit of trial and error to make it easier for me to compare the different bang combinations I'm going to copy and paste the raster layer in my table of contents and adjust the bang culmination for each one of these layers and then give each layer meaningful name for quick reference I'm interested in doing some vegetation analysis around the presidential range so I'm going to use a locate to find Mount Washington chutney and Mount Washington will pull up a list of similar names and then we'll display the list of those locations that match on the map now I'm going to compute NDVI or the normalized difference vegetation index this is very easy to do using the raster function in DVI so I'm opening up the raster functions tab searching for NDVI and clicking on it to launch the function any one of my layers can be entered as the input raster it's imperative that I understand my bands the visible band for this Landsat 8 composite is band 4 and the near-infrared band is band 5 entering the bands incorrectly here will produce invalid and DVI output I want my mdvi values to have a range from negative 1 to 1 so I'm going to check the box for scientific output and then when I'm ready to execute the NDVI tool I'm going to click create new layer the raster function and DVI creates a virtual layer pointing back to my original imagery so it executes almost instantaneously after renaming my leg on the table of contents I'm going to head over to the symbology tab I'm going to make sure I'm not displaying any background values of 0 and then I'm going to adjust the stretch type until I come up with something that I think displays the NDVI values the best finally I'm going to tinker with the color scheme choosing a ramp that goes from red meaning their vegetation to green which means higher concentrations of vegetation as I explore my NDVI lair I can see that areas of high amounts of vegetation such as the forested areas have high NDVI values displayed as green the features that are devoid of vegetation such as roads and water bodies and mountaintops have much lower NDVI values symbolized by the red color clicking on any individual pixel will display the NDVI value and they identify window one of the advantages of and minimizes the effect that lighting has on my data and around the presidential range we see the forested areas and shattered valleys are considerably darker than forested areas that are in unshadowed regions however when we move over to the NDVI layer we see that the effect of shadowing has been greatly reduced this is because lighting has a similar effect on both the near infrared and red bands and thus when we apply in DVI which is a ratio between those bands the effect is minimized in this video we showed you how to use globe is to access the Landsat scene that you're interested in create a multiband raster composite with an ArcGIS display the multispectral imagery using different band combinations and then finally compute NDVI

Channel: Jarlath O'Neil-Dunne

Views: 19,275

Keywords: ArcGIS, Landsat, Remote Sensing, GIS

Id: bb9_zANr76A

Length: 9min 52sec (592 seconds)

Published: Tue Jan 01 2019