About this Documentation

Notes and background information in no particular order...

Sample images

This documentation uses several sample images as examples in various topics.




The bronze sample image shows the equestrian statue of Henry IV (1553 - 1610) that stands at the Place du Pont Neuf just above the Square du Vert-Galant in the romantic heart of Paris.


Henry of Navarre became the first Bourbon king of France in 1589 at the age of thirty-five when his predecessor, Henry III, was assassinated. After a life of great difficulties as well as immense accomplishments Henry IV was assassinated on Friday, 14 May 1610. He was killed by a demented man who stabbed the king twice after leaping onto the royal coach when it was slowed by traffic congestion. The king had previously escaped another assassination attempt in 1594 when a law student had attempted to stab him at the Hotel de Schomberg.


Henry IV completed the Pont Neuf, which was begun during the reign of Henry III. He had become king under trying circumstances without the acceptance of the population but during his reign had won the hearts and minds of the French people. Henry IV proved to be a master of practical politics and directed the expansion of French power in Europe and overseas in North America. His support for exploration yielded discoveries such as Lake Champlain. At home, the king supported arts, learning and architecture. He died a beloved king, especially among common folk. Historians have long regarded him as one of the greatest of French kings.


The first equestrian monument to Henry IV was placed at the Pont Neuf by his widow, Marie de Medici. It was smashed by a revolutionary mob in 1792. In 1818 the next generation wished once more to remember the great king and emplaced the current monument. The Henry IV we see today was poured using bronze taken from the statue of Napoleon that was removed from the Vendome column.




Our sample ginevra image shows the portrait of Ginevra de' Benci by Leonardo da Vinci which hangs in the National Gallery of Art in Washington, DC, the only painting by Leonardo on public display in the US.


Painted when Leonardo was only 21, the portrait shows Ginevra at age 16 or 17, perhaps on the occasion of her betrothal or marriage, in what was for the time a revolutionary and lifelike pose, a three quarter view and not the more typical profile.  Ginevra already at 16 was known for her intelligence, her beauty and her virtue.


The early history of the painting is unknown.  It became part of the collections of the Prince of Liechtenstein in Vienna most likely in 1712.  During WWII it was transferred to the Prince's castle at Vaduz and stored in the wine cellar for safekeeping.  The Ginevra portrait was purchased in 1967 from the reigning Prince for the then-record sum of $5 million by Alisa Mellon Bruce as a gift for the National Gallery of Art.   


At one time the portrait was attributed to Cranach, but for many years experts knew it had to be a Leonardo.  That Leonardo painted Ginevra was conclusively proved in 1991 when during a cleaning his thumbprints were discovered where he had pressed the surface of the paint to soften transitions.





The schloss image shows the famous Neuschwanstein castle built by Bavaria's King Ludwig II (1845 - 1886) between 1869 and 1886. "Schloss" is a German word used for castle or chateau. Ludwig II was a man obsessed with romantic images of a medieval Germany that never was. He squandered his fortune building elaborate and expensive fairy-tale castles. The unfinished Neuschwanstein was the last and most dramatic of all.


Set where the Bavarian plain meets soaring Alps, the castle perches within a dramatic landscape of vertical crags and plummeting gorges. The photograph was shot from the Marienbrucke footbridge that vaults over a waterfall in the mountains above Neuschwanstein.


Although it is built in the imagined style of castles of medieval times, Neuschwanstein was created in the late 1800's as a dream castle for Ludwig II's personal fantasies. It is not a practical fortification even though it is sited at a highly defensible location once occupied by a true, fighting castle. Numerous design themes within the interior recall epic sagas and themes from Wagner's operas. The interior is only partly completed with sumptuous rooms for the king's apartments (including an artificial cave), a Singer's Hall for musical performances and a breath-taking throne room.


The king stayed at Neuschwanstein for but a few days during the latter stages of construction. In 1886 he was beset by creditors and facing bankruptcy when a Bavarian government commission declared him mentally deranged. A delegation sent to Neuschwanstein convinced him to leave the castle on 12 June and return to Munich for treatment. The next day, the king and his personal physician, Dr. Gudden, both were found dead in the Starnberg See, a large lake on the route from Neuschwanstein to Munich. An inquiry failed to reveal whether the deaths were an accident, suicide or murder.


The Free State of Bavaria now owns Neuschwanstein and operates it as one of Bavaria's most popular tourist attractions. In life a distant and lonely man, in death Ludwig II has become a Bavarian pop icon.





The SanFran image is a sample Landsat 7 image downloaded from a USGS web site as a JPG image. This is path 44, row 34 using Band 3, 2, and 1. Composition of Landsat bands into a JPG format image was done by USGS. Date of acquisition is not known but is believed to be spring of 1999. The image shows the spring runoff from the Sierra Nevada mountains and other neighboring mountains into San Francisco Bay and out into the Pacific.


Clearly visible are the numerous regions and famous landmarks of this fascinating area. In the upper right is the Delta, the confluence of the Sacramento and the San Joaquin rivers. The waters of this region drain through Suisun Bay, through Carquinez Strait and into San Pablo Bay, the large and shallow bay at the northern extremity of San Francisco Bay. The South Bay is the local term for the large, mostly shallow part of the bay that reaches from San Francisco to the South and East. A less enclosed bay is the upper portion of Monterey Bay in the Pacific Ocean, visible at the bottom of the image.


This region is the home of the microprocessor, invented by Ted Huff at Intel in Santa Clara in 1971. The Santa Clara Valley ("Silicon Valley" or simply "The Valley" to locals) is the heavily developed region at the Southeast extremity of the South Bay. The first commercial microprocessor was the Intel 4004, which contained about 2300 transistors on a die ("chip") slightly larger than one inch square.   


Although originally known for silicon technology, the region is also the epicenter of the venture capital funding revolution that has powered business and technology breakthroughs in software, systems, biotechnology and most recently, the Internet, social media and the phenomenal wealth created by advertising on Internet.  Where once orchards bloomed and then later manufacturing blossomed, the greatest wealth of all is now generated by utilizing advanced surveillance of consumer browsing habits to inject advertising into the minds of ever more  consumers worldwide.


The region also remains a center of weapons technology.  The Livermore Valley appears as a horizontal streak of development just East of the South Bay. Livermore is the home of the Lawrence Livermore National Laboratory, the nuclear weapons design center created as an alternative to Los Alamos in the 1950's with an initial mission focussing on the development of thermonuclear weapons. The nuclear weapons storage depot near Suisun Bay in Concord is said to host one of the highest concentrations of nuclear weapons in the world.


This image reveals an interesting juxtaposition. On the original image we can see beige and duff yellow colored regions on the edge of the bay near Silicon Valley. These are salt ponds where seawater is evaporated in the commercial production of salt. The same region where people invented and once manufactured the most advanced technology ever conceived is also the place where one of the most ancient production processes continues to be practiced.

Historical Notes

A few notes of historical interest, mainly thumbnail biographies, have been scattered throughout the documentation in the following topics.


Tau Rho Alpha - Robinson Projection


Jean Dominique Cassini, Jacques Cassini, Cesar Francois Cassini de Thury, Jean-Dominique, comte de Cassini  - Cassini Projection


Christopher Columbus - Projections Tutorial


René Descartes - About Coordinate Systems


J. P. G. Lejeune Dirichlet - Transform: Voronoi Diagrams


Carl Friedrich Gauss - Transverse Mercator Projection


Emile Guyou - Guyou Projection


Ferdinand Rudolph Hassler - Polyconic Projection


Johan Heinrich Lambert - Lambert Azimuthal Equal Area Projection


Gerardus Mercator - Mercator Projection


Charles Sanders Peirce - Peirce Projection


John Parr Snyder - Space Oblique Mercator Projection


Leonardo da Vinci - Example: Change the Contrast of an Image


Georgi. F. Voronoi - Transform: Voronoi Diagrams

Avatars and Photos

Advice: An avatar or photo representing engineering staff often appears near caution warnings, tech tips or other useful information.



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