How to Share a Photogrammetry Dataset of Aerial Images with Clients

Sharing a large photogrammetry dataset of aerial images requires balancing data integrity with accessibility. The most effective approach involves exporting high-resolution orthomosaics and digital surface models in standard formats like GeoTIFF or LAS, while providing interactive web-based viewers for lightweight client review. This dual strategy ensures clients can access detailed GIS data without overwhelming their systems.

Preparing the Dataset for Export

Before sharing any files, you must ensure the raw photogrammetric data is processed into usable deliverables. A dataset consisting of several thousand aerial images is too large for direct email or basic file transfer protocols. Instead, focus on generating derivative products that represent the spatial information accurately. Start by creating an orthomosaic, which is a georeferenced image mosaic where each pixel has a specific location on the earth's surface. Ensure the resolution is sufficient for the client’s intended use case, typically measured in centimeters per pixel (GSD). Next, generate a Digital Surface Model (DSM) or Digital Elevation Model (DEM). These raster files contain height information derived from the point cloud. If your clients require 3D visualization, export the dense point cloud as a LAS or LAZ file. LAZ is preferred because it uses lossless compression, significantly reducing file size while preserving all coordinate and intensity data. For smaller projects, a textured mesh in OBJ or FBX format may be appropriate, but this often results in very large files that are difficult to share. Always verify the Coordinate Reference System (CRS) matches the client’s requirements, such as UTM zones or State Plane coordinates, to prevent misalignment when they integrate the data into their own GIS software.

Selecting the Right Delivery Format

The choice of file format dictates how easily your clients can open and utilize the data. Avoid sending proprietary project files from software like Agisoft Metashape or Pix4D unless specifically requested. Clients rarely have licenses for these tools. Instead, stick to industry-standard open formats. For imagery, GeoTIFF is the gold standard in GIS. It embeds geospatial metadata directly into the image header, allowing any GIS platform to recognize its location immediately. For elevation data, ASCII Grid or GeoTIFF are widely supported. If the dataset includes vector data, such as boundaries or features extracted from the model, use Shapefile or GeoJSON. Shapefiles are robust but have limitations on field length, so check for compatibility if using older GIS versions. GeoJSON is better for web applications but can become unwieldy with complex geometries. When dealing with point clouds, LAZ is superior to LAS due to compression. However, some older viewers cannot read LAZ files, so providing both formats might be necessary if you are unsure of the client’s technical capabilities. Always include a README.txt file explaining the contents, coordinate system, and units used.

Utilizing Web-Based Sharing Platforms

Direct file transfers fail when dealing with terabytes of data. Cloud storage solutions like AWS S3, Azure Blob Storage, or Google Drive are essential, but they do not provide visual context. Clients need to see the data before downloading it. Use specialized photogrammetry viewing platforms such as Pix4Dcloud, Agisoft Photoscan Web, or open-source alternatives like Orpheus or Cesium ion. These platforms allow you to upload your orthomosaic and point cloud once, then generate a shareable link. These web viewers offer zooming, panning, and measurement tools, enabling clients to explore the site remotely. They also handle the heavy lifting of rendering large datasets in the browser. You can restrict access with passwords or expiration dates to maintain security. Additionally, consider integrating the data into a web map service using Leaflet or OpenLayers if you have development resources. This allows for deeper customization, such as overlaying the aerial imagery on other basemap layers. As noted in our guide on Setting Up Spyder/JupyterLab Environment to Run QGIS Programs, scripting environments can help automate the generation of these web-ready tiles if you are processing many similar projects.

Best Practices for Collaboration

Communication is key when delivering complex geospatial data. Provide clear documentation outlining what each file contains and how to open it. Include instructions for installing necessary plugins or viewers if the format is niche. Offer a trial period for web viewers so clients can test compatibility with their internal workflows. Be prepared to answer questions about data accuracy, ground control points, and error margins. Transparency builds trust and reduces support requests after delivery. Avoid overloading clients with unnecessary layers. If they only need the orthomosaic, do not send the full point cloud unless requested. Conversely, if they are engineers requiring precise elevations, omitting the DSM could render the dataset useless. Tailor the package to the specific use case. Regularly update the shared links if revisions are made, ensuring everyone works with the latest version. Finally, archive your original project files securely. You may need to regenerate derivatives if the client requests changes later. By following these steps, you streamline the handover process and enhance client satisfaction.

Frequently Asked Questions

What is the best format for sharing aerial imagery?

GeoTIFF is the most widely accepted format for aerial imagery in GIS applications. It preserves geospatial metadata and supports various compression methods to manage file size. Most professional mapping software can read GeoTIFF files without additional plugins.

How can I reduce the size of a point cloud for sharing?

Convert your LAS point cloud to LAZ format, which applies lossless compression. This can reduce file sizes by up to 90% without losing any data. Ensure your client’s viewer supports LAZ files before sending them.

Do clients need special software to view web-shared data?

No, web-based viewers run in standard web browsers like Chrome or Firefox. Clients only need an internet connection and a modern browser to interact with the uploaded orthomosaics and point clouds.

What should I include in the README file?

Include the coordinate reference system, units of measurement, date of capture, sensor details, and processing software version. Also list the contents of each file and any specific instructions for opening them.

Can I share data via email if it is small enough?

Email attachments are limited to around 25MB. Even small orthomosaics often exceed this limit. Use cloud storage links instead, even for smaller files, to ensure reliable delivery and easy updates.