Author: Tobler, Waldo

Source: Cartography and Geographic Information Science, Volume 29, Number 1, January 2002 , pp. 17-23(7)

Publisher: Cartography and Geographic Information Society

Abstract:

The qibla problem—determination of the direction to Mecca—has given rise to retro-azimuthal map projections, an interesting, albeit unusual and little known, class of map projections. Principal contributors to this subject were Craig and Hammer, both writing in 1910. A property of retro-azimuthal projections is that the parallels are bent downwards towards the equator. The resulting maps, when extended to the entire world, thus must overlap themselves. An unusual recent discovery from Iran suggests that Muslims might have been prior inventors of a similar projection, by at least several centuries. A later corollary by Schoy leads to a new "cylindrical" azimuthal map projection with parallels bending away from the equator, here illustrated for the first time.

Keywords: AZIMUTHAL DIRECTIONS; MAP PROJECTIONS; MECCA; QIBLA; RETRO-AZIMUTHALS

Document Type: Research article

DOI: http://dx.doi.org/10.1559/152304002782064574

Publication date: 2002-01-01

More about this publication?

• Cartography and Geographic Information Science (CaGIS) is the official publication of the Cartography and Geographic Information Society. CaGIS supports research, education, and practices that improve the understanding, creation, analysis, and use of maps and geographic information. The society serves as a forum for the exchange of original concepts, techniques, approaches, and experiences by those who design, implement, and use geospatial technologies through the publication of authoritative articles and international papers. The role of the CaGIS journal is to facilitate these objectives by disseminating results and reports in these areas of interest.
  
  Cartography and Geographic Information Science (CaGIS) is now being published by Taylor & Francis as of 2013. Please visit the Journal's website at www.tandfonline.com/tcag or contact subscriptions@tandf.co.uk to subscribe and obtain online access.
  
  
• Editorial Board
• Information for Authors
• Submit a Paper
• Subscribe to this Title
• Membership Information
• CaGIS publications
• NIH sponsored research - Policy
• ingentaconnect is not responsible for the content or availability of external websites

Related content

• In this: publication
• By this: publisher
• In this Subject: Computer and Information Sciences ,  Geography
• By this author: Tobler, Waldo

Website © Publishing Technology. Article copyright remains with the publisher, society or author(s) as specified within the article.

• Terms and conditions
• Privacy policy
• Information for advertisers