Overlaying Contours and GeoTIFF in ArcGIS

The contour files export, in the Elevation toolbox, are available to all customers subscribed to Individual, Advanced, Teams, or Enterprise plans. These set of tools can equip users with elevation data that can be exported and displayed in GIS software for further analysis.

In this guide, we will learn how to export DXF and SHP contour files from DroneDeploy and import them into ArcGIS. Additionally, we will cover how to overlay them on a GeoTIFF resulting in a bold, data rich display to share with your stakeholders.

Exporting Contour Files and Elevation Map from DroneDeploy

Download the Elevation Map and the Contour files from DroneDeploy. While exporting the files (GeoTIFF, SHP, DXF) ensure that you select the same Map Projection for all of them.

Once the data has been exported and downloaded to your computer, it is time to use ArcGIS

Changing the Spatial Reference System using ArcCatalog

In order to overlay the contour files (SHP or DXF) on top of the TIFF file, we have to ensure that all of them have the same Spatial Reference within ArcGIS. To do this, let’s open ArcCatalog and reproject the coordinate systems, in case we notice some discrepancy within the coordinate system of the 3 files.

1. Open ArcCatalog and select the file path of the exported files.
2. First, let’s check the coordinate system of the SHP file:

• Open the folder that contains the SHP file
• Right-click on it and select Properties

• In the Shapefile Properties window, you can check the current coordinate system. Note that this file is spatially referenced using WGS_1984_Web_Mercator_Auxiliary_Sphere using the EPSG code 3857 as shown in the image below.

Let’s use this specific coordinate reference system to reproject the other files (if it is needed).

3. Now, let’s check the coordinate system of the DXF file:

• Open the folder that contains the DXF file
• Right-click on it and select Properties

• As you can see in the CAD Feature Dataset Properties window, in the General tab, the Spatial Reference of this file is Unknown. Let’s assign the same coordinate reference system of the SHP.

• Click on Edit button to change the coordinate system.
• In the search bar, in the Spatial Reference Properties window, type "3857" and press Enter. Click on the coordinate system that shows up to select it and click OK.

Note that the Spatial Reference System for the DXF file is now using WGS_1984_Web_Mercator_Auxiliary_Sphere (EPSG code 3857). Click OK to apply the changes.

4. Finally, let’s check the coordinate system of the TIFF file:

• Open the folder that contains the TIFF file
• Right-click on it and select Properties

• In the Raster Dataset Properties window, in the General tab, scroll down to the Spatial Reference information and click Edit to check the coordinate reference system.

• In the Spatial Reference Properties window, you can see that the current coordinate system is WGS_1984_Web_Mercator_Auxiliary_Sphere but it doesn’t have any EPSG code related to it.

• In order to select the right coordinate system, let’s type the correct EPSG code which is: 3857 in the search bar and press Enter. Click on the coordinate system that shows up to select it and click OK.

• In the Raster Dataset Properties window, click OK again to apply the changes.

Great job! Now our files are using the same coordinate reference system and they are ready to be imported into ArcMap.

Importing GeoTIFF into ArcMap

1. Open ArcMap and start a new project
2. Click on Add Data icon to import the files.

3. Let’s start adding the Elevation Map by selecting the TIFF file path and click on Add.

If you the Elevation Map is rendering incorrectly, please follow the steps described in the Displaying Elevation Data in ArcGIS documentation to display your map. Once the TIFF file rendering has been corrected, you should see something like this:

Now, let's overlay the contour files on top of the Elevation Map. You can choose to import either the SHP or the DXF file, both are vectorial information and can be imported into ArcMap.

4. To import the SHP file, let's click on Add Data icon. Go to the SHP location and click Add.

Congrats! Now you should see the SHP file overlaid with the Elevation Map as shown in the image below.

5. Now, to import the DXF file, click on Add Data icon. Go to the DXF location and click Add

Once the DXF file has been imported you should see something like this:

The DXF files in ArcGIS are represented by five CAD feature classes (Annotation, Point, Polyline, Polygon, and MultiPatch). In order to display and overlay the contour lines on the Elevation Map, we have to choose only the Polyline feature within the DXF file. To do so please follow the next instructions:

• In the Table of Contents window, expand the DXF layer to visualize the components of the CAD file.

• Uncheck all of the components, except the Polyline as shown in the image below.

Congratulations! You have overlaid the DXF file on top of the Elevation Map: