2025/2026

Developing new mapping exercises/activities

Oblique imagery viewer

In 2025, KyFromAbove released a statewide archive of oblique aerial photography. Oblique photography shows the sides of surface features, buildings, trees, etc., which are not shown in typical aerial photography that we use in digital mapping. Let’s explore this data via a website that allows us to download the full-resolution images.

Visit this webpage: https://boydx.github.io/phase-3-oblique-centroids and zoom into an area that interests you. The airplane icons represent locations where five photographs were taken:

  1. Straight down, or nadir.
  2. Forward
  3. Backward
  4. Left
  5. Right

For example, if a plane is flying northbound (the red icon), the forward exposure points north and the image tilts to the south. Click on an airplane to access the five exposures.

OK, let’s explore the imagery based on where the center of each exposure is located. We call this the oblique centroid. Click the paper airplane icon in the upper left corner.

Visit webpage
Visit webpage and click the paper airplane icon.

Now, you’ll need to zoom into an area even closer to clearly see the oblique centroid icon. The icon’s shape indicates which way the camera faces.

Enable the oblique centroids layer
Enable the oblique centroids layer.

Click a few icons to access the images. Your browser might be able to preview the image, but you can also download the TIFF for closer inspection. In this example, we have found the Kentucky State Capitol.

Download TIFF
Download Kentucky State Capitol TIFF for closer inspection.

Discussion

  1. What are the advantages and disadvantages of oblique imagery compared to traditional aerial photography?
  2. Can you identify any privacy concerns related to the use of oblique imagery?
  3. Compare Google Street View imagery with oblique imagery. What are the key differences and potential use cases for each?

How high is that thing?

Often we think of maps as tools to help us navigate to a desired locations. They might provide a route, distance, and even the elevation of the terrain. But how do we accurately measure the height of a building, tree, or other structure above the ground?

Over the past few decades, lidar (Light Detection and Ranging) technology has emerged as a powerful way of measuring elevations. By emitting laser pulses and measuring the time it takes for them to return, lidar can create highly accurate elevation models.

A digital elevation model (DEM) is a 3D representation of the ground surface with all of the above-ground features removed, e.g., trees and buildings. DEMs are widely used in various applications, including flood modeling, land-use planning, and resource management. A digital surface model (DSM), on the other hand, includes all of the above-ground features and is useful for applications such as urban planning and forestry. When you subtract the DEM from the DSM, you get the above-ground heights of buildings and trees.

Let’s explore Lexington (inside New Circle Road) using lidar data from KyFromAbove. Point your browser to this webpage: https://boydx.github.io/urban-observation-towers. Explore the map and discover that it shows trees, buildings, and even parking garages – a.k.a urban observation towers.

Visit webpage
Visit webpage and explore campus rendered from lidar data.

Notice the icons in the upper-right corner? These tools allow you you to view the map as a typical 2D map or a bird’s eye view. If you enable the terrain mode and right-click + pan the map, you can see the elevation changes more clearly.

Enabling the bird’s eye view
Enabling the bird’s eye view.

If you left-click the map, a circle is dropped with a number where you clicked. The number represents the height of the feature at that location. For example, WT Young Library is approximately 165 feet tall. How high is your dorm or favorite place on campus? Good facts to know!

Sampling height above ground.
Sampling height above ground.

Discussion

  1. Can you tell a building’s use based on its height and shape?
  2. What are the implications of the height data for urban planning and development? For example, what if we could find all buildings in the city that never received shadows?
  3. Which areas of the city have the most and highest tree canopy?

Making a custom map in ArcGIS Online

ArcGIS Online (AGOL) is a cloud-based platform that allows users to create and share data and maps. It provides access to a wide range of basemaps, data layers, and analysis tools, making it a powerful resource for aspiring GIS professionals.

To access AGOL, you will be given instructions on how to log into the platform. Check your email for details. Once you have a login, point your browser to UKy’s AGOL page: https://uky-edu.maps.arcgis.com

UKy’s AGOL Portal
UKy’s AGOL Portal.

OK, once you log in, take a moment to explore. This platform host projects not just for you, but for the entire UKy community of mapping enthusiasts. When you’re ready to make your first map, land on the Content tab. You might want to create a new folder for your course to help organize your projects, e.g., GEO 109.

Let’s say you have created a CSV for important locations on campus:

lat,lon,message
38.032826, -84.501967, "Starbucks in Willie T. Library"
38.043185, -84.501881, "Local Taco"
38.038875, -84.501347, "Bowman"
38.034451, -84.495570, "Great Bagel & Bakery"

Click on New Item to start the process of adding this data to your account.

Adding a new item to AGOL.
Adding a new item to AGOL.

Follow the prompts to upload your CSV file and configure the layer settings. Once your data is uploaded, you can view it on a map and share it with others.

Drag and drop the file onto the menu.
Drag and drop the file onto the menu.

Make sure the latitude and longitude fields are correct.
Make sure the latitude and longitude fields are correct.

Give the layer a useful name and description.
Give the layer a useful name and description.

Now, click Save. You have successfully added your data to AGOL and made a layer that can be used in your maps. Explore the item’s page to discover methods for sharing, publishing, and exporting the data. When you’re ready to make a map, click Open in Map Viewer.

Start building your new map.
Start building your new map.

This last step is the exciting part of map making: bringing your data to life in a custom map! You have many options from which to choose, including different basemaps, symbology, and pop-up configurations. A good approach to designing your map is following these steps in order:

  1. Select a basemap because that will determine how your data is displayed. Consider the purpose of your map and choose a basemap that complements it.
  2. Edit the marker style to make it more visually appealing and informative. You can change the color, size, and shape of the markers to better represent your data.
  3. Add and configure the labels for your markers to provide context and information to the map users.
  4. Save your map and then share it with others.

Bringing your data to life in a custom map.
Bringing your data to life in a custom map.

OK, good luck and have fun!