Spherical geometry is the geometry of the two-dimensional surface of a sphere.

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Specifying a rectangle as two latitude/longitude pairs, one for center and one for size

I am trying to make sense of the Google S2 library for spherical math (it works like this). I need to get a rectangle for searching for nearby entities in a database, based on a point and a distance ...
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110 views

Rhumb lines intersection

I looking for algorithm how to find out whether two rhumb lines given by point1 with azimuth1 and point2 with azimuth2 have intersecting point. Have anyone idea how to find intersection ? For ...
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Mercator bias plot in Leaflet

I was inspired by this wikipedia image from the mercator projections page to hack around with leaflet. The idea was to interactively have your cursor move a continent and that it would be corrected ...
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How can I convert LIDAR based measurement to UTM coordinate?

I have lidar based measurement with azimuth elevation and range, I would like to convert this data to UTM coordinate. I know the position of the lidar in UTM coordinate system, so I developed the ...
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519 views

Bearing/Course/Heading in WGS84 ellipsoid model

There is a common formula for computing the initial bearing for a course from lat1, lon1 to lat2, lon2. (And yes, I'm aware that the course will change when traveling). atan2( sin(lon2-lon1) * ...
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How can I figure out whether a sphere is intersecting the Earth between a given lon/lat range?

Given a lon/lat range that represents a tile on the Earth's surface, I need a computationally efficient way to figure out if a spherical volume defined by a point (assume ECEF coordinates) and a ...
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91 views

Find arc endpoint with bearing and radius counting with curvature of the earth?

So my problem is that I have start point [lat,long] for arch, bearing, radius and I need compute end point [lat,long] ? End point should be in 180 degrees angle from start point and I should be aware ...
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142 views

Centroid of the equator and a point

Suppose I already have a way to compute the centroids of different geometry types: Points (arithmetic mean of Cartesian coordinates). Linestrings (polylines) (weighted mean of segment mid-points in ...
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Placement of a fixed-radius circle on a sphere to maximize point containment

There are many papers on the "Circle Placement Problem" in 2D Euclidean space, but I haven't been able to find any papers discussing this problem on the sphere. The problem is: given a set of points ...
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Intersection between a ray from lat, lon, alt, with pan, tilt and earth's surface

I have a problem that consists of finding the intersection point between a ray from a given lat, lon, alt, that is looking to a given pan and tilt angles and the earth's surface. I need the lat, lon ...
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57 views

How to approximate point to segment distance on sphere?

I would like to approximate the distance of a line segment from a reference point on the map (coordinates are gives as lat/lon). In the Cartesian coordinate system I would simply find the closest ...
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159 views

Locating the centroid (center of mass) of spherical polygons

I'm trying to work out how best to locate the centroid of an arbitrary shape draped over a unit sphere, with the input being ordered (clockwise or anti-cw) vertices for the shape boundary. The density ...
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27 views

recalculate latitude and longitude from a pixel in a cropped map

i want to recalculate a geographic coordinate from a pixel in a map. For this i have the size and the coordinates from the map to convert a coordinate to a pixel is use the algorithm, you find at ...
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Feature.geometry.transform not working

// World Geodetic System 1984 projection var WGS84 = new OpenLayers.Projection("EPSG:4326"); // WGS84 Google Mercator projection var WGS84_google_mercator = new ...
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Implementing custom (Vincenty/Haversine formula) functions for MySQL vs Using PostGIS?

I currently am using MySQL for all of my relational data. I have hit a crossroads with geo calculations. Since, MySQL does not have good support for spatial functions, I am contemplating on using ...