How we mapped Dieppe

Open Street Maps

The first part to mapping Dieppe began with collecting as many original maps of Dieppe in 1942 as possible. Town Plans, topographic maps from the Geographical Section General Staff (GSGS), Defensive Overprints, and contemporary maps from C.P. Stacey.

Each of these maps were then georeferenced in ArcGIS to provide an accurate coordinate system for mapping. Using the buildings from Open Street Map (OSM) data we then compared the contemporary vector with the 1942 raster maps. Using OSM buildings from 2022 as a base, we were then able to delete buildings from new areas of development, and add in buildings that were destroyed over time such as the famous Casino on the Promenade. The intent was not to get a perfect 100% exact town replica, but to have the shape of the town of Dieppe and for the surrounding areas to be similar to how it was in 1942.

Defensive Overprints

Four different defensive overprints were georeferenced to provide a good base to map the defensive positions of Dieppe and surrounding areas. This allowed our team to compare multiple versions and accurately map out the defensive situation on Dieppe. Things that were mapped include:

• bunkers

• machine posts

• gun batteries

• obstacles (trenches, barbed wire)

• radar stations

What are defensive overprints? Defensive overprints are topographical maps that contain enemy defensive positions. This information is generally generated from aerial reconnaissance flights. Photo reconnaissance planes will typically fly directly over top of an objective taking a series of overlapping photographs. With enough overlap, images can be viewed with a stereoscope creating a perception of 3d depth, allowing enemy positions and structures to be mapped out.

Creating the web map, timeline and narrative

The web map is meant to be used as a visual guide to the battle. Plenty of detail is still missing, as it is impossible to map every aspect. Many units are not represented on the web map such as the sappers and gunners of the engineer and artillery units respectively. This is for several reasons: first the goal is to keep the web map simple enough to run on the average computer and internet connection, but complex enough to showcase the entire battle. Second, many of these units were smaller detachments attached to the main force, and are much harder to represent at the scale we are showing other units. Third, the battle was chaos. While the web map shows units as cohesive units, this is merely a representation. Units, commanders, officers, sergeants and soldiers a like were scattered across their respective beaches fighting for their lives. Few units were able to fight as a whole during the battle.

Finally, this web map should be reviewed through the lens of its sources which can be seen in the methodology section below. Much of the timeline and narrative has created using reports on the battle from the Canadian Army’s Second World War historian Colonel C.P. Stacey . Since the original reports created by C.P. Stacey much has been written about Dieppe. Therefore there will be elements missing from this project. Because of this the project will remain open to be refined over time. If you wish to submit an error or omission that you see with the project you can file a report below.

Sources used in the Dieppe web map

Naval Staff History - Raid on Dieppe (Naval Operations - Historical Section Admiralty

Operation Jubilee - Information from German War Diaries - C.P. Stacey

Operation Jubilee - Part I: The Preliminaries of the Operation - C.P. Stacey

Operation Jubilee - Part II: The Execution of the Operation - Section 1 : General Outline and Flank Attacks - C.P. Stacey

Operation Jubilee - Part II: The Execution of the Operation - Section 2 : The Attack on the Main Beaches - C.P. Stacey

Operation Jubilee - Part III: The Execution of the Operation - Some Special Aspects - C.P. Stacey

Dieppe Through the Lens - Henry/Pallud

Open Project

The Dieppe web map is an open project that we will continue to refine with help from the community. We know that there are many people who have spent considerable amount of time researching specific parts of the battle. We are open to any submissions, but reserve the right to decide which elements do or do not make it into the project. If you wish to contribute, make a suggestion or provide a resource please use our report form below:

Report a bug, error or omission

Have you found a bug that needs to be reported? Is there an error or omission that you think we should amend? Use our Google Form to make a report and we will look into all issues.