The North Dakota Dept of Water Resources developed this service as a way to repurpose the thousands of air photos and maps that we have collected over the last 70+ years. Since we started this project, over 40,000 photos have been scanned from the NDDWR offices, 60,000 photos from State Archives, 19,000 photos from the State GIS Technical Committee and several thousand historical photos from the ND Geological Survey, USDA NRCS and various state agencies. Most were scanned from standard 9-inch paper photos (a mix of BW, Color, and CIR). We now have approximately 300 of our projects available here, which include over 150,000 photos available for viewing, comparison, or download. Additionally, we provide newer digital airphotos from county and state collects along with Federal products such as NAIP and USGS DOQQs. We have over 500,000 historical photos that are yet to be scanned/geo-registered. Photos are available from the late 1930's thru the 2021. While we would like to have all of our photos online right now, please understand that we have very limited resources to throw at this project and basically only 2 people to maintain and grow the service. If you have any questions about data for specific areas, please don't hesitate to contact us.

*One caveat:

In order to get these photos into a format where they could be easily found and dropped into a GIS system, they had to be geo-registered after scanning. Since the vast majority of photos are of North Dakota prairie, we decided to simply register them with only 3 or 4 control points to make it easier to find the photo you want with a map service. What this means to you, is that they are NOT ortho-rectified and there WILL be radial distortion and edge-matching problems. For this reason we have included both clipped and unclipped versions of these photos. The clipped photos allow us to loosely mosaic the photos without photo borders getting in the way. The unclipped versions allow users to download photos and register them using the original fiducial marks and a generalized camera model with more advanced software. If we had spent the time trying to ortho-rectify all of our photos, we would have never been able to provide this service. Newer digital photos are provided in their original format and will drop into mapping software with no distortion problems.

A Quick Tutorial

When you first bring up the map service, you will be presented with a map of the state of North Dakota. On the left will be a listing of all the photo projects available for viewing or download. Traditional map navigation tools are available to the upper left of the map with the zoom-in button on by default and highlighted in red. There is also a box to the right of the navigation tools for zooming to a particular township and range. To the upper right of the map area is a “Show Layers” button which will allow you to turn on/off map features such as roads, hydrography or annotation. In the lower left of the screen you’ll also find a link to zoom to a particular scale or longitude and latitude.

The left side of the screen is where you’ll find the aerial photography projects. The listing is alphabetical by project name. The NDDWR has scanned in all of our aerial photography and most were gathered for particular projects. When they were scanned, they were scanned by the project. The problem with this method is that it’s hard to find photos based on a project name as that project might cross county borders, be named by relatively obscure aquifer names, small towns, dams, etc. The map service takes care of that problem by allowing us to search geographically with the map. The naming of the projects typically follows the convention of “where is it_date_phototype”. So for example, if you just opened the map service, you’ll probably see the AgnesMarsh_19900813_cir project. It is photography from the Agnes Marsh area taken on 8/13/1990 and is color infrared.

You can scroll through the list on the left to see all the projects. The default search method for finding photos is to use the map extent of the map to the right. So, for example, when you first get into the map service, you’ll get a listing of everything in our inventory because it’s showing the whole state of North Dakota. If you use the zoom tool to zoom into a small area on the map, you’ll see that the list on the left of the screen becomes smaller because it is only showing you the projects that fall within the map extent you are currently viewing.

Above the list, in the very upper left corner of the screen, are four tabs for finding available data. These are the different tools available to geographically search for photography. The first is highlighted by default when you initially get into the map service and is the Map Extent tab. The list you see on the left is generated by the map extent you are seeing on the right. The second is the Map Selection tab. Clicking on this tab will allow you to search based on a left-click and drag to create a rectangular search, or by simply left-clicking on the map and selecting a search radius. Once selected, you will notice that the list on the left will shorten to include only those projects that contain photos within the extent specified. The next tab allows you to search by feature. The current feature list allows you to search by county, township, section and watershed. When you select a feature from the pull down window, that feature layer will be highlighted in yellow. Simply click on a feature (such as a specific county) and the project list will be shortened to show only the projects that intersect the selected feature. The last tab will allow you to define an irregular polygon feature. You might use this option to define an area that follows a stream course or maybe a highway segment. Simply click points to add your polygon and when finished, click on the “Query in Polygon” button up under the tab. This will then shorten the list on the left to only projects that fall within your defined extent. Clicking and dragging on the red control points of your polygon will allow you to modify your polygon vertices and clicking on the hollow black squares located at the middle of every segment will allow you to add vertices to your polygon. You can reset the area selected by clicking on the “Reset Drawing” button just below the tabs. Clicking on the map extent tab will remove the yellow selection box when you want to start viewing photos up close.

Each of the projects is located in the list in a gray, rectangular box.

Clicking anywhere on the gray area will turn on this project. It will be highlighted in red, and, if you are zoomed out beyond a 1:50,000 scale (recall that the scale is shown in the lower left corner of the screen) you will only see the photo footprints. Clicking anywhere on the gray box will turn it off. You can click on the yellow magnifying glass in the gray box and that will zoom you to the project extent which may or may not get you close enough (1:50,000 scale or greater) to have the photos start appearing.

If you have zoomed in to a scale of 1:50,000 or greater, the photos will begin to appear. Clicking on another project will turn the current project off and the newly selected project on. You can use this functionality to compare photos from different collects/years. If you zoom in far enough, the photo file names/flight lines/photo dates will be printed on the screen.

The “I” button will give you some general information about the project and will also indicate whether the photography is ortho-rectified, pseudo-ortho, or preliminary geo-registration. It provides the dots per inch (dpi) of the scan and an estimated or exact pixel resolution.

Clicking on the green, downward pointing arrow will allow you to download all of the photos in the project or only those photos from within your current map extent. Keep in mind that some of these projects have over 10,000 photos and that the average color photo runs about 400mb and average black and white photo is about 160mb. When you click on the arrow button, a window will appear similar to below:

You have a choice of downloading all of the photography from the project, or only those photos you are viewing in your map extent. Additionally, there are frequently two different types of photos available: clipped and full (unclipped). The reason for this is that the vast majority of photos we’ve scanned come from traditional 9x9” paper/film photos. These photos still had the fiducial marks, compasses, altimeters, etc on the edges along with the borders of the photos. We’ve clipped all of these types of photos so they will loosely mosaic for use in a mapping system, however, we’ve scanned and geo-registered approximately 40,000 photos from our collection and we only registered them with a quick 3 or 4 point method. We store both clipped and unclipped versions so you can have the ability to download the unclipped version, and using a general photogrammetric model, be able to use the fiducial marks and general camera information to better register the original photo with many more control points.

Having mentioned the limited control points, it should also be noted that sometimes registration between photos will not be perfect. We’ve tried to do our best, but sometimes it’s just impossible to find good control, or topography, particularly in the western part of the state, causes problems along with the naturally occurring radial distortion from the camera lens. However, we are including newer digital photography as we get it, and you shouldn’t have a problem with these. They come natively as clipped photos, so there are no “unclipped” versions.

Disclaimer

This data is provided by the ND Dept of Water Resources for your convenience. This data is provisional. This service is provided "AS IS" and without warranty of any kind, either express or implied. No warranty, either expressed or implied, is made regarding the accuracy or utility of the data or information presented at this site. The ND Dept of Water Resources is not responsible for any errors or damages that may occur resulting from the use or mis-use of the data that is provided at this site.

If you have any questions regarding the data, generation methods, or errors, please direct any comments to Rod Bassler at the ND Dept of Water Resources.