Geog 121 Project 4: Finding LandSat Data Shawn R. Gill Mark J. Imperial Lawrence Herrighty Jr. Carolyn S. Fish Richard K. Naffin

History Behind LandSat Originally called the Earth Resource Technology Satellite Program Launched the first satellite, ERTS-1 in 1972. In 1975, NASA renamed the program Landsat There have been six successful Landsat launches (with the exception of Landsat 6). Landsat 7 was successfully launched in 1999. The next Landsat satellite is projected to be launched in 2010.

What Exactly Is Landsat? Landsat is used to observe the surface of the Earth through the use of thermal infrared and visible light satellite images with a resolution of 60 meters. It is one of the most accurate imagery tools available. The primary goal of Landsat 7 is to continually update the archives of satellite images of Earth.

How to Find a LandSat Image First, go to http://earthexplorer.usgs.gov. Enter the site by clicking on ‘guest’.

‘Spatial Coverage’ Directions Under ‘Spatial Coverage’, go to ‘Enter Place Name’ Then, enter your town’s name and select your state. Then, press search. Then, simply select your town out of the list. After selecting town, close all the pop-up windows. The coordinates of your town will appear under ‘Spatial Coverage’.

‘Data Set Selection’ Directions Under ‘Data Set Selections’, click on the ‘+’ in front of ‘Satellite Imagery’. Then, click on ‘LandSat 7 ETM+ SLC off. (July 2003 to present)’ Then, click ‘continue’.

Cloud Coverage On the next screen, go down to ‘Cloud Cover’ and select “Less than 10%”. Click ‘Search’. Once the status turns from ‘Running’ to ‘Complete’, hit the results icon.

Selecting Correct Image Choose the image file with a ‘normal’ classification and cloud cover of ‘0’ In the below example, choose row 3.

To Find Metadata Under ‘Show All Fields’, select ‘show’ to open up the Metadata file for row 3. Save the opened file directly under your ‘www’ folder. Afterwards, you can create a hyperlink to that file in order to open it from your project webpage.

This Is The Metadata File.

Downloading the Image Under ‘Preview Image’, select the icon ‘show’ to display the satellite image. Unselect ‘Show Grid’ to remove the yellow lines. Then save the photo in your ‘Image’ folder using the usual techniques.

The Landsat Image

Now You Can Create Your Project Page

Why the Lines? An Instrument malfunction occurred on Landsat 7 on May 2003. The failure occurred with the Scan Line Corrector, which compensates for the satellites continuous forward motion while in orbit. The lines are data gaps roughly the size of 400 meters. Most of the data errors are along the edges of the image.

What is WRS Path and WRS Row? WRS is the ‘Worldwide Reference System’. WRS Path refers to the orbit number of satellite (WRS equivalent of latitiude). WRS Row refers to the scene center number of image (WRS equivalent of longitude). Landsat 7 uses WRS-2, with a 16 day repeat cycle (it is basically the orbit). WRS grid is comprised of 233 paths and 248 rows.

WRS-2 Path/Row

Info For Project All the information for the rest of the write-up can be found in the linked metadata file. Prices can be found at http://earthexplorer.usgs.gov. under ‘prices’.

To see a copy of this presentation, go to: http://www. personal. psu

Works Cited http://landsat.usgs.gov http://earthexplorer.usgs.gov. http://campus.esri.com http://en.wikipedia.org/wiki/landsat http://landsat.gsfc.nasa.gov. http://landsathandbook.gsfc.nasa.gov/handbook.html