Monday, December 8, 2014

How to use the USGS EarthExplorer website

As promised here is the "How to use the USGS EarthExplorer website" guide for the people of the NICKELPLATEROADmodeler Yahoo Group.

In planning a NKP Wheeling Division Adena branch line layout that could better fit my basement space, I quickly found out just how hard it was to find photos of that area. After traveling down to those areas myself several times, I saw why the southeastern end of the Wheeling wasn't photographed as much. It's a good out of the way drive for most people and not easy to get down and around to find things!

Luckily I found through the United States Geographical Service's EarthExplorer website I could download old black and white aerial photographs that gave me a window far enough into the past to help me locate trackside structures, terrain conditions, buildings and houses, even how industry and yard tracks were used.

The detail you will find is not of Google Maps satellite quality, but is good enough when nothing else is available.

Here's an example of the Hanna Coal Company's Glen Castle Mine south of Harrisville, Ohio on the Adena Branch in 4-16-1958. I've have yet to find a decent ground level photo of this facility, so this aerial photo is good enough to zoom in and learn more than I previously could about the mine.

Hanna Coal Co.'s Glen Castle Mine on the Adena Branch near Harrisville, OH 4-16-1958

Two things about EarthExplorer
  1. Your time period of interest may not be available for every geographic area. Some areas might only have data from the 1970s for example, but I've seen some with choices from the 1940's through the 1970's.
  2. Your time period of interest might be only available in a high altitude view that gives poor detail. Some aerial photos look like they were takes from a U2 spy plane but with a Polaroid instant camera. Usually there is a photo set from at least one year that can give good detail.

Let's Get Started

I'll go step by step, each step broken down with photo examples. It might be it too simple for some but not everyone is computer savvy I've learned.

Before we start you will need a unzipping program for the high resolution photos, these are usually 70-100MB each and are compressed into a .gz file format. Also make sure you have some available hard drive space if you plan on downloading a lot of aerial photos!

Winzip at has a free trial and is popular.
7-Zip at is an open source unzipping program that is completely free. 7-Zip is what I use but I'm sure there are other great programs out there that are similar.

Step 1

Go to

Register for an account. Yeah... I would just want to get to the good stuff right away too, but take the time and make an account. Because you can't get to the high resolution photos without one..

You can fill in the "User Affiliation" fields like this, I haven't had any government men in suits knocking on my door yet, so these must've been good answers.

OK, now finish up and login.

Step 2

Let's pick a location, for this example we'll check out the heart of the Wheeling & Lake Erie, Brewster, Ohio!

There's two ways to do this.
Type in the name of the city and state and hit the show button.

Underneath where you entered the address, the name of your town has now appeared with some coordinates. Click on the name of your town.

Bam! A little red marker appears on Brewster. This red marker tells the EarthExplorer exactly where you want data from.

Two (this is much easier):
Don't enter an address(unless you really have no idea where a location is!), instead just click on the map and the red marker will appear.
Here I've zoomed in to the yard at Brewster and clicked on it, dropping the marker where I want the data.

Step 3

Now click on the "Data Sets" tab to choose the kind of photo data you want.

We want "Aerial Imagery". Click on the plus sign next to Aerial Imagery to open up that menu.
That Declassified Data looks pretty intriguing huh? Maybe scroll the map over to Nevada? Nah, maybe another time, back to trains.

The only thing we want to select is the "Aerial Photo Single Frames". I haven't looked through all the categories yet, but so far Aerial Photos is where we want to go for older data usable for our needs.

Step 4

Time for results, literally. Click on the "Results" tab.

Now let's look at what we've got.  

You may have multiple pages of results, don't forget to click the "next" at the top or bottom of the current shown data set to see more results.

There's a thumbnail of the actual aerial photo, along with the date is was taken and the scale it's in.

The higher the scale number the worse detail you get.
Remember the U2 spy plane using a tiny Polaroid Instant Snap Camera? Yeah a scale of 80,000 is like that. Shoot for a scale under 30,000 otherwise it's not worth it, under 20,000 is the best.

Only 3 of those funny little buttons for each photo are important enough to worry about for our needs.

Show Footprint
This button shows the footprint of the aerial photo on the map in an opaque colored square. This is handy to compare which aerial photo will give you the best coverage of your subject.

Show Browse Overlay 
This button shows a small image of the aerial photo as it would appear on the map. Most of the time however, it is rotated the wrong way and won't match up with the surrounding roads and such. Any picture viewer or Photoshop can easily fix this after you download it.

Show Download Options
This button will give us the option to download the aerial photo in high resolution . Click it and choose the High Resolution option.

I use Google Chrome for my web browser and most of the time the "Download Options" window will go away. Sometimes it doesn't, but it's still safe to close it and your download will still start once the proper connections are made. The EarthExplorer photo servers can be very slow at times, but if you see this in the lower left corner of your browser(may be different for Internet Explorer or Mozilla Firefox, etc), then its all good.

Finally its downloading...

Step 5

Let's open that file and see what Brewster yard looked like on May 9th, 1971.

Your unzipping program should automatically open the file, but if not, you may have to select it from a list of programs to use.

Once it's open lets extract the aerial photo file to a new location for use.

Here I chose a folder already made for my collection of aerials. Once there I'll rename it with the location and date, because 1VCRE00040118 just doesn't get the same information across to me.

Don't forget to delete the original zipped file from your downloads folder if you've extracted the aerial photo to a new location for safe keeping.

Step 6

Now however you chose to file away your photos, let's go and open that aerial and see what we've got!

Here's a close up of the Brewster Engine Shop and Turntable. Even for one of the well photographed Wheeling locations it's still pretty neat to see like this! Even more fun when you start comparing changes from other dates at the same location!

Roundhouse & Engine shop area, Brewster, OH 5-9-1971
Finally here's a good comparison between the medium and high resolutions. You can easily see why you don't bother with anything but the high resolution.

Roundhouse & Engine shop area, Brewster, OH 4-25-1960
As I found out not all parts of my favorite railroad were photographed equally, but these aerial photos help fill the gaps of the unknown.
I hope this long guide was helpful in using the USGS EarthExplorer website. Thanks for making it to the end!

1 comment:

  1. Perfect! Thank you for sharing this great tool. Especially good for me not living in the US. Best regards! Jacob from Sweden