John Mccombs

by Monday, April 16, 2012 @ .

I have been with the Coastal Remote Sensing Program at the NOAA Office for Coastal Management in Charleston, South Carolina, since 2003. At the office, I oversee the quality control of the moderate-resolution Coastal Change Analysis Program (C-CAP), as well as coordinate mapping efforts in support of the Sea Level Rise and Coastal Flooding Impacts Viewer. Before NOAA, I worked on Gap Analysis Program land cover mapping projects in Virginia and Mississippi and helped run the Spatial Information Technologies Laboratory at Mississippi State University.

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Coffee and Landsat?

Back in July 2007,  I started a wholesale account with a coffee distributor. Since that time, my co-workers and I have ordered 1,371 pounds of coffee beans. After doing some Google searches, I discovered that there are approximately 3,350 coffee beans per pound, and each pound will make about 2 gallons of coffee. That means I have ordered over 4,592,850 beans, which could in turn make about 2,742 gallons of coffee. 

What does this have to do with Landsat 5 though? Did you know that Landsat 5 was launched in March 1984 with a planned 3 year operational life? Did you also know that it was still collecting data this past fall? It has only recently stopped collecting imagery due to some on-board system failures. Well, we know what keeps my co-workers and I going all day, but what kept Landsat 5 going (on-board percolator maybe)?  I don’t know the answer, and frankly I am not that concerned with the “why.”  I’m just glad it had the ability to impersonate the energizer bunny and keep going, and going, and going…

Landsat History

Landsat 5Throughout this time span, the biography of Landsat 5 takes on a near soap-opera quality. On March 1, 2012, Landsat 5 turned 28. On this day it entered its 148,932nd orbit around Earth and has traveled more than 4.1 billion miles- greater than the distance between the Sun and Pluto (landsat.gsfc.nasa.gov/news/news-archive/news_0446.html).  It has suffered from temporary technical issues and was brought back to life by a team of dedicated engineers, changed owners, became commercialized, then back to public stewardship with the price of imagery changing from ~$650 per scene, to upwards of $4400 per scene, to free.  It is this last part that really makes Landsat special.

In April 2008, the USGS announced its intention to provide the full archive of all Landsat data (among other satellite data sets) for free! Scientists around the world rejoiced with the news! Just imagine what could be done with the thousands of images available from the early 1970s! Since 1984, imagery was collected up to 23 times per year for the whole U.S. using Landsat 5.  The imagery has been used in trend analysis, climate change, crop studies, forest patterns, water quality, geology, coral reef health, natural disaster assessments, and recovery monitoring- the list goes on and on. Heck, we even use it for our moderate resolution Coastal Change Analysis Program!  Seeing the connection to needing coffee yet?


Number of images captured by Landsat TM 5 in 2011. Image courtesy of USGS.

Data Access

Now let’s say you want some of this awesome, free data.  How would you go about getting it? The USGS has been kind enough to make it quite simple for us actually. The two most common sites are GloVis and EarthExplorer. Prior to using these sites, all you have to do is register. Once in the system, you can browse the whole suite of available data sets, from different sensors and across time. You can even view thumbnails of the data prior to selection, just to make sure clouds aren’t blocking your pretty view from above. Once downloaded, the data will be ready to be used in your favorite image processing software (of course it is never that simple, but that is a topic for future blogs).

The Next Landsat Cup of Joe?

With Landsat 5 on its last legs (antennas?), and Landsat 7 operating in a degraded mode (not covering that topic here either…), what is next? The Landsat Data Continuity Mission (LCDM), a collaboration between the U.S. Geological Survey and NASA, is the next generation moderate resolution satellite. Planned for launch in January 2013, it will share many of the same characteristics of Landsat 5 and boast some improvements as well. More detailed specifications can be found at www.nasa.gov/mission_pages/landsat/overview/index.html.

We can only hope that the engineers of the LCDM partook in their fair share of coffee and have massively over designed this satellite, and it is able to follow in the giant footsteps of Landsat 5.

2 Responses to “1,371 Pounds of Coffee Beans and Landsat 5”

  1. Kirk Waters

    Hi John,

    I wanted to let you know that I have enjoyed reading your blog. Your comment about avoiding “clouds blocking your pretty view” in your satellite images made me laugh. They’re not so pretty when they are covering up your study area! Interference from the atmosphere has always been one of the biggest problems in remote sensing, and a large obstacle to radiometric accuracy. You could easily devote a whole blog post to Atmospheric Corrections that might be needed for an image even if you don’t actually see puffy white clouds, since distortion from the atmosphere can make pixels in your image brighter than they would have been otherwise.
    Anyway, I will continue to read and enjoy.

    Cheers!
    Jessica Edwards