The Mercator projection is a cylindrical map projection presented by Flemish geographer and cartographer Gerardus Mercator in 1569. It became the standard map projection for navigation because it is unique in representing north as up and south as down everywhere while preserving local directions and shapes. The map is thereby conformal. As a side effect, the Mercator projection inflates the size of objects away from the equator. This inflation is very small near the equator but accelerates with increasing latitude to become infinite at the poles. As a result, landmasses such as Greenland, Antarctica, Canada and Russia appear far larger than they actually are relative to landmasses near the equator, such as Central Africa.
In navigation, bearing or azimuth is the horizontal angle between the direction of an object and north or another object. The angle value can be specified in various angular units, such as degrees, mils, or grad. More specifically:
In navigation, a rhumb line, rhumb, or loxodrome is an arc crossing all meridians of longitude at the same angle, that is, a path with constant bearing as measured relative to true north.
A compass rose, sometimes called a wind rose, rose of the winds or compass star, is a figure on a compass, map, nautical chart, or monument used to display the orientation of the cardinal directions and their intermediate points. It is also the term for the graduated markings found on the traditional magnetic compass. Today, a form of compass rose is found on, or featured in, almost all navigation systems, including nautical charts, non-directional beacons (NDB), VHF omnidirectional range (VOR) systems, global-positioning systems (GPS), and similar equipment.
The Cantino planisphere or Cantino world map is a manuscript Portuguese world map preserved at the Biblioteca Estense in Modena, Italy. It is named after Alberto Cantino, an agent for the Duke of Ferrara, who successfully smuggled it from Portugal to Italy in 1502. It measures 220 x 105 cm.
In marine navigation, a pelorus is a reference tool for maintaining bearing of a vessel at sea. It is a "simplified compass" without a directive element, suitably mounted and provided with vanes to permit observation of relative bearings.
Angelino Dulcert, probably the same person known as Angelino de Dalorto, and whose real name was probably Angelino de Dulceto or Dulceti or possibly Angelí Dolcet, was an Italian-Majorcan cartographer.
A wind rose is a graphic tool used by meteorologists to give a succinct view of how wind speed and direction are typically distributed at a particular location. Historically, wind roses were predecessors of the compass rose, as there was no differentiation between a cardinal direction and the wind which blew from such a direction. Using a polar coordinate system of gridding, the frequency of winds over a time period is plotted by wind direction, with colour bands showing wind speed ranges. The direction of the longest spoke shows the wind direction with the greatest frequency.
Portolan charts are nautical charts, first made in the 13th century in the Mediterranean basin and later expanded to include other regions. The word portolan comes from the Italian portulano, meaning "related to ports or harbors", and which since at least the 17th century designates "a collection of sailing directions".
The Padrón Real, known after 2 August 1527 as the Padrón General, was the official and secret Spanish master map used as a template for the maps present on all Spanish ships during the 16th century. It was kept in Seville, Spain by the Casa de Contratación. Ship pilots were required to use a copy of the official government chart, or risk the penalty of a 50 doblas fine. The map probably included a large-scale chart that hung on the wall of the old Alcázar of Seville. Well-known official cartographers and pilots who contributed to and used the map included Amerigo Vespucci, Diogo Ribeiro, Sebastian Cabot, Alonzo de Santa Cruz, and Juan Lopez de Velasco.
"Majorcan cartographic school" is the term coined by historians to refer to the collection of predominantly Jewish cartographers, cosmographers and navigational instrument-makers and some Christian associates that flourished in Majorca in the 13th, 14th and 15th centuries until the expulsion of the Jews. The label is usually inclusive of those who worked in Catalonia. The Majorcan school is frequently contrasted with the contemporary Italian cartography school.
Catalan charts or Catalan portolans are portolan charts in the Catalan language. Portolan charts are a type of medieval and early modern map that focuses on maritime geography and includes a network of rhumb lines. Most medieval portolan charts were made in Italian-speaking cities, with a substantial minority made in Catalan-speaking Majorca. In the 19th century, historians of cartography emphasized the differences of style and content between Italian and Catalan charts, but other authors have nuanced this distinction since then.
Cartography throughout the 14th-16th centuries played a significant role in the expansion of the kingdoms of the Iberian Peninsula for a multitude of reasons. Primarily, the maps developed during this period served as navigational tools for maritime folk such as explorers, sailors and navigators. Mostly the expansion of the Crown of Aragon (which included the Kingdom of Aragon, Kingdom of Valencia and Kingdom of Majorca, together with the Principality of Catalonia, all its territories with seashore on the Mediterranean Sea. The Crown of Aragon controlled the routes across the Mediterranean Sea from the Kingdom of Jerusalem to Europe, as part of the commercial-trade route known as the Silk Road.
Guillem Soler, sometimes given as Guillelmus Soleri, Guillermo Soler and Guglielmo Soleri, was a Majorcan cartographer of the 14th century.
The rule of marteloio is a medieval technique of navigational computation that uses compass direction, distance and a simple trigonometric table known as the toleta de marteloio. The rule told mariners how to plot the traverse between two different navigation courses by means of resolving triangles with the help of the Toleta and basic arithmetic.
The Mercator world map of 1569 is titled Nova et Aucta Orbis Terrae Descriptio ad Usum Navigantium Emendate Accommodata. The title shows that Gerardus Mercator aimed to present contemporary knowledge of the geography of the world and at the same time 'correct' the chart to be more useful to sailors. This 'correction', whereby constant bearing sailing courses on the sphere are mapped to straight lines on the plane map, characterizes the Mercator projection. While the map's geography has been superseded by modern knowledge, its projection proved to be one of the most significant advances in the history of cartography, inspiring map historian Nordenskiöld to write "The master of Rupelmonde stands unsurpassed in the history of cartography since the time of Ptolemy." The projection heralded a new era in the evolution of navigation maps and charts and it is still their basis.
Loxodromic navigation is a method of navigation by following a rhumb line, a curve on the surface of the Earth that follows the same angle at the intersection with each meridian. This serves to maintain a steady course in sailing.
La Cartografía Mallorquina is a book of essays on the Majorcan portolans written by Professor Julio Rey Pastor with the collaboration of Ernesto García Camarero. It is a scholarly essay, a key element in the study of portolans, especially those made by Majorcans as half of the book is devoted to the study of more than 400 Majorcan portolans existing worldwide.
Salvatore de Pilestrina, also known as Salvat de Pilestrina, was a mapmaker in Mallorca in the early 16th century.
