Milestone-Proposal:Invention and First Demonstration of Radar

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Docket #:2015-01

This Proposal has been approved, and is now a Milestone

To the proposer’s knowledge, is this achievement subject to litigation? No

Is the achievement you are proposing more than 25 years old? Yes

Is the achievement you are proposing within IEEE’s designated fields as defined by IEEE Bylaw I-104.11, namely: Engineering, Computer Sciences and Information Technology, Physical Sciences, Biological and Medical Sciences, Mathematics, Technical Communications, Education, Management, and Law and Policy. Yes

Did the achievement provide a meaningful benefit for humanity? Yes

Was it of at least regional importance? Yes

Has an IEEE Organizational Unit agreed to pay for the milestone plaque(s)? Yes

Has an IEEE Organizational Unit agreed to arrange the dedication ceremony? Yes

Has the IEEE Section in which the milestone is located agreed to take responsibility for the plaque after it is dedicated? Yes

Has the owner of the site agreed to have it designated as an IEEE Milestone? No

Year or range of years in which the achievement occurred:


Title of the proposed milestone:

Invention and First Demonstration of Radar, 1904

Plaque citation summarizing the achievement and its significance:

Hohenzollernbrücke, Cologne (The original brigde "Feste Brücke" has been replaced by this one in the same location)

In what IEEE section(s) does it reside?


IEEE Organizational Unit(s) which have agreed to sponsor the Milestone:

IEEE Organizational Unit(s) paying for milestone plaque(s):

Unit: IEEE Germany Section
Senior Officer Name: Prof. Jens Haubrock, Chair

IEEE Organizational Unit(s) arranging the dedication ceremony:

Unit: MTT/AP Joint Chapter (CH08008)
Senior Officer Name: Dr. Peter Knott, Chair

IEEE section(s) monitoring the plaque(s):

IEEE Section: IEEE Germany Section
IEEE Section Chair name: Prof. Jens Haubrock, Chair

Milestone proposer(s):

Proposer name: Hugh Griffiths
Proposer email: Proposer's email masked to public

Proposer name: Peter Knott
Proposer email: Proposer's email masked to public

Proposer name: Wolfgang Koch
Proposer email: Proposer's email masked to public

Please note: your email address and contact information will be masked on the website for privacy reasons. Only IEEE History Center Staff will be able to view the email address.

Street address(es) and GPS coordinates of the intended milestone plaque site(s):

50°56'27.6"N 6°57'46.1"E

Describe briefly the intended site(s) of the milestone plaque(s). The intended site(s) must have a direct connection with the achievement (e.g. where developed, invented, tested, demonstrated, installed, or operated, etc.). A museum where a device or example of the technology is displayed, or the university where the inventor studied, are not, in themselves, sufficient connection for a milestone plaque.

Please give the address(es) of the plaque site(s) (GPS coordinates if you have them). Also please give the details of the mounting, i.e. on the outside of the building, in the ground floor entrance hall, on a plinth on the grounds, etc. If visitors to the plaque site will need to go through security, or make an appointment, please give the contact information visitors will need. The site is on the banks of the Rhine, right next to the Hohenzollern Bridge where the original experiment was conducted.

Are the original buildings extant?

The original demonstration was outdoors

Details of the plaque mounting:

The plaque will securely mounted on an outdoor wall, protected by a toughened glass window to protect it from the weather and from damage.

How is the site protected/secured, and in what ways is it accessible to the public?

The site is fully accessible to the public

Who is the present owner of the site(s)?

The City of Cologne

What is the historical significance of the work (its technological, scientific, or social importance)?

The German engineer and entrepreneur Christian Hülsmeyer first had the idea to build a device for detecting and locating objects by means of electromagnetic waves. He founded his own company, raised venture capital and developed the technical concept of a radar system. He also patented his invention (which he called "Telemobiloskop") and first demonstrated it in Cologne, Germany, in 1904. These were the foundations of modern radar systems which, today, have conquered many areas of our life: Not only in military and geoscience systems but also in automotive, industrial or home applications.

What obstacles (technical, political, geographic) needed to be overcome?

At the time of his invention, RF technology was still in its infancy. The available electronic devices were so primitive that, compared to today's standards, Hülsmeyer's system had only poor performance. Although he could successfully demonstrate the detection of ships on the river Rhine, the German and Dutch Navy were not interested and did not support him.

What features set this work apart from similar achievements?

Other scientists and engineers, including Nikola Tesla and Guglielmo Marconi, had suggested that it might be possible to detect objects using reflected electromagnetic waves, but Hülsmeyer’s work was the first practical demonstration and the subject of the first patents. Some sources – particularly the British scientist Sir Robert Watson-Watt who developed the British Chain Home radar system in the UK in the late 1930s – maintain that Hülsmeyer’s invention could not properly be called a radar because it did not measure range (the term ‘radar’, standing for radio detection and ranging, had first been introduced in the USA on 19 November 1940). This is not strictly true, since a development of Hülsmeyer’s invention, detailed in a subsequent patent granted on 2 April 1906, did indeed measure target range. In addition, we have no difficulty today in speaking of police Doppler radars – which measure target velocity but not range.

Supporting texts and citations to establish the dates, location, and importance of the achievement: Minimum of five (5), but as many as needed to support the milestone, such as patents, contemporary newspaper articles, journal articles, or chapters in scholarly books. 'Scholarly' is defined as peer-reviewed, with references, and published. You must supply the texts or excerpts themselves, not just the references. At least one of the references must be from a scholarly book or journal article. All supporting materials must be in English, or accompanied by an English translation.

Arthur O. Bauer, Christian Hülsmeyer and about the early days of radar inventions - a survey, Diemen, 2005

Supporting materials (supported formats: GIF, JPEG, PNG, PDF, DOC): All supporting materials must be in English, or if not in English, accompanied by an English translation. You must supply the texts or excerpts themselves, not just the references. For documents that are copyright-encumbered, or which you do not have rights to post, email the documents themselves to Please see the Milestone Program Guidelines for more information.

1. Louis Brown: Technical and Military Imperatives: a Radar History of World War II, Taylor & Francis, 1999.

2. David Pritchard: The Radar War: Germany’s Pioneering Achievement 1904-1945, Harper Collins, 1989.

3. Sean Swords, Technical History of the Beginnings of Radar, Peter Peregrinus, 1986.

4. Arthur O. Bauer: Christian Hülsmeyer and about the early days of radar inventions - a survey, Diemen, 2005 [a detailed description of Hülsmeyer’s work and patents written by a Dutch historian and made available on his website ]

5. A Special Session at the SEE/IEEE International Radar Conference in Toulouse, France in 2004 to mark the centenary of Hülsmeyer’s invention. Several of the papers are in French, but two in English are:

Arthur O. Bauer: ‘Hülsmeyer’s early radar commitments’

Jean-Marie Colin: ‘Radar innovation and proofs from C.Hülsmeyer’

Please email a jpeg or PDF a letter in English, or with English translation, from the site owner(s) giving permission to place IEEE milestone plaque on the property, and a letter (or forwarded email) from the appropriate Section Chair supporting the Milestone application to with the subject line "Attention: Milestone Administrator." Note that there are multiple texts of the letter depending on whether an IEEE organizational unit other than the section will be paying for the plaque(s).