All-in-One Lightweight GIS Platform

Space Oblique Mercator (SOM) Projection is a sophisticated, specialized map projection designed specifically for mapping the continuous surface coverage of Earth-observing satellites in near-polar, sun-synchronous orbits. Conceived in the 1970s by Alden P. Colvocoresses and later refined by John L. Junkins, John P. Snyder, and others, it solves a unique problem: accurately representing the curved, swath-based ground track of a satellite moving in space while the Earth rotates beneath it. Unlike traditional projections that treat the Earth as static relative to the Sun, the SOM mathematically models the dynamic relationship between the satellite's orbital path and the Earth's rotation, creating a nearly conformal map where the satellite's ground track is represented as a straight line with minimal scale distortion along the swath.

General Perspective Projection is a family of azimuthal map projections that simulate the view of the Earth from an arbitrary point in space, creating a perspective effect akin to a photograph taken from a distant observer. Unlike orthographic or stereographic projections which assume specific viewing distances or geometric relationships, this projection allows flexible positioning of the projection point—either above the Earth's surface (for satellite or aerial views) or at an infinite distance. It is particularly valuable for visualizing planetary bodies from space missions, generating realistic global and regional views, and supporting applications in astronomy, remote sensing, and scientific visualization where naturalistic perspective is prioritized over geometric preservation.

Tissot Indicatrix is a classical method in cartography used to quantify and visualize distortions inherent in map projections. Developed by French mathematician Nicolas Auguste Tissot in the 19th century, it provides a precise geometric tool for analyzing how angles, areas, and shapes are deformed when transferring locations from the Earth's surface to a map. Rather than representing a projection itself, the indicatrix consists of plotting infinitesimal circles onto a projection grid to demonstrate how they become ellipses or other shapes under different projection transformations. This method enables an intuitive and scientific comparison of projection properties and remains foundational for evaluating projection suitability across mapping, geomatics, and geographic education.

Oblique Mercator Projection differs from the standard Mercator and Transverse Mercator projections by orienting the axis of the projection cylinder obliquely relative to the Earth's rotational axis and equator. This projection is designed to minimize distortion along a specific straight line or great circle, making it well-suited for high-precision representation of regions that are elongated in a diagonal direction. Notable examples of its use include mapping the Alaska Highway, long-distance pipelines, and geological structures that extend diagonally.

Patterson Cylindrical Projection is a pseudocylindrical projection proposed in 2014 by Tom Patterson, a cartographic editor at the National Geographic Society. Designed to emphasize visual balance, it aims to mitigate the excessive polar distortion seen in projections like Mercator and the vertical distortion characteristic of sinusoidal projections. As a result, it can depict the entire world with a gentle and natural impression. Although not an equal-area or conformal projection, it evenly distributes distortions in area, shape, and distance, making it suitable for modern world map representations.

Natural Earth Projection is a pseudocylindrical world map projection proposed in 2009 by Tom Patterson and Bo Jenny. Designed to prioritize visual naturalness and overall balance, it is characterized by its ability to depict a harmonious global image without excessively distorting the shapes of landmasses and oceans. As a compromise projection that does not strictly adhere to equal-area, conformal, or equidistant properties, it is widely adopted for applications that value clarity and aesthetics, such as statistical maps, educational maps, printed materials, and web maps.

Kavrayskiy VII Projection is a world map projection classified as a pseudocylindrical projection. It was proposed in 1939 by the Russian cartographer Vladimir V. Kavrayskiy. Unlike projections that strictly preserve properties such as equal area or conformality, it is designed to visually represent the entire Earth in a balanced manner. It notably controls distortion in area and shape at high latitudes, avoiding extreme exaggeration and presenting a moderate appearance. This projection has primarily been used for thematic and overview world maps.

McBryde–Thomas Flat‑Polar Sinusoidal Projection is a compromise world map projection designed by American cartographers F. Webster McBryde and Paul D. Thomas in the mid‑20th century. It aims to balance area distortion, shape preservation, and visual readability. This projection adopts a flat‑pole design in polar regions to reduce high‑latitude stretching and incorporates sinusoidal meridian distribution to improve shape accuracy in mid‑to‑low latitudes. It is suitable for global‑scale thematic mapping and educational communication purposes.

Quartic Authalic Projection is a pseudocylindrical equal-area projection independently developed by Karl Siemon in 1937 and Oscar S. Adams in 1945. It is derived by modifying the Lambert azimuthal equal-area projection, featuring a straight central meridian approximately 0.45 times the length of the equator, with other meridians represented as fourth-order algebraic curves and parallels as straight lines perpendicular to the central meridian. The poles are depicted as points. While significant shape distortion occurs along the edges due to excessive convexity of the meridians, the scale remains accurate along the equator and any given latitude, making it suitable for thematic world maps requiring precise area preservation.

Bonne Modified Projection is an equal-area pseudoconical projection method, an optimized variant of the classic Bonne projection. It preserves equal-area properties while improving shape distortion in peripheral regions. Originally proposed by the French cartographer Rigobert Bonne in the 18th century, this projection has undergone multiple mathematical refinements to meet modern cartographic needs. It is particularly suitable for mapping medium-scale regions at mid-latitudes. By parameterizing adjustments to the standard parallel and central meridian, the modified Bonne projection achieves a balance between equal-area accuracy, shape fidelity, and directional rationality, making it a common choice for thematic and regional planning maps.