# Questions tagged [geodesic]

A geodesic is the shortest path between two points on a curved surface; in this context applies to questions where the curved surface is the earth's surface.

45 questions
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### Difference between haversine formula & geodesic distance for calculating distance

Background I have Vehicle driving data which includes Lat/Long points of a particular route. I drive in that route for 2 times. The driving data in that route is around 20 minutes. (Approximately ...
89 views

### Get lat/long given current point, distance and bearing

While searching the web, I've encountered the following formulas for calculating the destination point P2's location given the source point P1 = (lat1,long1), the distance from it & the bearing: ...
25 views

### Understanding Projection for Near tool in ArcMap?

I need to find the nearest distance of points from points in ArcMap. Both layers are in WGS 1984. When I choose geodesic distance in Near tool, I get results in meters. I don't do any projection. ...
113 views

### Leaflet.Geodesic.js line not drawn

I am trying to use Leaflet.Geodesic.js geodesic to draw a geodesic line between two points, but I don't see any line at all. Based on the Leaflet.Geodesic.js example script, this is what I have tried....
76 views

### If rectangle corner points have same nearest neighbor, does whole interior?

If all four corners of a spherical (but actually WGS84/elliptical) rectangle are closest to a given point p in a set S, does that necessarily mean all points inside the rectangle are also closest to p?...
59 views

### Non-iterative algorithms for direct problem in the study of geodesic

I am finding an appropriate algorithm to implement in my program for direct problem in the study of geodesic. In brief, the direct problem deals with finding the end point (its longitude, latitude and ...
56 views

### Geodesic multiple ring buffer in ArcGIS

The Buffer tool in ArcGIS 10.5 allows for the creation of geodesic buffers, however, I am unable to find that option for the Multiple Ring Buffer. I have 10 areas around which I need to create 6 ...
128 views

### Converge origins on destination leaflet geodesic

I am using Tabletop.js to map locations on a leaflet map. With each row I add the lat lng to a feature group and then to the map. What I would also like to do is use leaflet geodesic to draw a line ...
88 views

### Calculate perimeter of a large polygon using geodesic calculations

How do I calculate perimeter of a large vector polygon (polygon set) which spans almost half the globe? I guess regular calculations do not produce accurate results in this case.
84 views

### Understanding geodesic envelope?

I've been looking at some various ways to calculate geodesics. One particularly good site collecting load of helpful information, is this one. There you can also find a link to a map that shows a ...
125 views

### Is there an open source library that offers geodesic buffering of large polygons?

I need to buffer some large polygons and minimize distortion. Is there an open source library that offers negative and positive geodesic buffering of large polygons? I am aware ESRI has an ...
144 views

### ArcGIS Point every 100 meters along poline

ArcObjects with ArcGis 10.1 I have constructed a polyline in WGS84 that has straight segments and curved segments. The line is heavily geodesically densified. Now I have to step through every 100 ...
351 views

### Calculate turn required to follow a line of latitude

Lines of latitude are not geodesic except at the equator. So to follow perfect eastern course in the northern hemisphere in a vehicle a left turn is constantly required. We can express a turn as the ...
82 views

### Finding crossing point between geodesic line and parallel?

Given a geodesic line (starting point and initial azimuth) is there an algorithm to find the longitude of the [first] crossing of a given parallel? I have already checked with Clairaut's constant ...
766 views

### Euclidean and Geodesic Buffering in R

In Understanding Geodesic Buffering, The Esri Geoprocessing Development Team distinguish between Euclidean and Geodesic Buffering. They conclude with "Euclidean buffering performed on projected ...
63 views

### Definition of “most northwesterly point” on a landmass?

If we are using a 2D representation of a landmass, with north represented as up and east as right, then we can conceptualise the most northwesterly point as being the last point we reach when we place ...
156 views

### Calculating distance between two Lat Long points with different altitudes? [closed]

If we assume that the altitude is held constant, the great circle distance is correct. However if the radius of the circle is not constant how can the distance be calculated? In my case the altitude ...
310 views

### Creating a geodetic line that goes around the whole ellipsoid with pyproj

https://jswhit.github.io/pyproj/pyproj.Geod-class.html Pyproj's Geod class has a npts method to create points on the geodesic between two points: npts(self, lon1, lat1, lon2, lat2, npts, radians=...
208 views

### ArcPy Insert cursor losing vertices when writing Polygon features?

I'm currently trying to code a geodesic buffer from points (the one that is implemented in ArcGIS is very slow). The idea is to calculate 100 point coordinates (P_Buffer) around an initial point (P) ...
401 views

### Hive GIS ST_GeodesicLengthWGS84 not returning expected distance

I am trying to find the distance between two points (in meters and not degrees) using GIS Tools for Hadoop by ESRI. The ST_Length provides distance in degrees and hence I used the ...
507 views

### What's wrong in using latitude and longitude as X and Y on a Cartesian space?

What can go wrong and what kind of error can build up if I use geodetic coordinates as if they were cartesian and place my objects into my world with no conversion formulas?
266 views

### JTS Vividsolutions API: compute First (direct) geodetic problem

I'm using the popular JTS Vividsolutions API for Java. I'm struggling to find if I can perform calculation of the First (direct) geodetic problem with the API. Is there a way to calculate this with ...
460 views

### Measuring Geodesic Distance in ArcGIS for Desktop? [closed]

I'm working with only a basic/student license for ArcGIS 10.1 on an ocean mapping project. I've created a grid that covers all ocean area, capturing various characteristics within that grid (the ...
2k views

### Get Radius in epsg 4326 with Openlayers 3

What is the best method for getting the radius of a circle in Openlayers 3 in epsg 4326 (geodesic)? I'm using this example for a base and trying to draw a circle while getting the radius, but using ...
2k views

### testing if a Geodesic polygon contains a point c++

I am looking for an algorithm, preferrably in C++, that can take a point (lon,lat) and determine whether that point is inside a geodesic polygon. Is there such an algorithm freely available?
3k views

### How to draw a circle in OpenLayers 2 and measure its radius dynamically?

With OpenLayers 2.13, I want to draw a circle and obtain its radius at each mousemove. The radius would then be returned as arguments of a callback function, for example. But of course, this is not ...
796 views

### Modifying straight line segments to follow geodesic / great circle paths using QGIS?

I have a kml file showing a dodecahedron stretched across the surfce of a globe, which I downloaded here: http://montalk.net/cgi-bin/coordinates.py I would like to re-project this dodecahedron so I ...
214 views

### Direct Geodesic with Point 2 Azimuth

I am trying to find a way to calculate the direct problem on the WGS-84 ellipsoid but instead of using the initial Azimuth (e.g. lat1, lon1, distance, fwd azi), I want to compute it with the reverse ...
455 views

I think I understand the whole rhumb line and great circle idea but I can't seem to find an answer on this question. Suppose I am driving a car (i don't use ship because I don't want to put the ...
166 views

### Calculate geographic position based on azimuth, distance and height [duplicate]

How to calculate the geographic position of an object in sky (Point B)(like an aircraft) from Home Point (Point A) based on only four variables: Lattitude and Longitude at Home Point, Azimuth at ...
590 views

### Alternatives to the Vincenty geodesic functions in OpenLayers 3?

I'm migrating an application from OpenLayers 2 which uses OpenLayers.Util.destinationVincenty() to compute the projected latitude and longitude of a point from an origin given an angle and distance in ...
184 views

### Prior art on rhumb line and great ellipse areas?

I'm adding the computation of the area betweeen a rhumb line or a great ellipse and the equator to GeographicLib. My formulations are briefly given in here and here. These formulations are similar ...
845 views

### How to validate OpenLayers area calculation using PostGIS?

I am working on a GIS API that work on top of OpenLayers. I have a feature that calculates the area of a drawn polygon. I have tested it on the browser and the areas I got, appear to be correct. For ...
232 views

### Which one of these azimuth values is the right one? And why?

First of all, let's make clear that I want the Azimuth on the surface of the Earth, i.e. the angle between two locations, for example New York and Moscow. I am testing some azimuth calculations with ...
469 views

### Is the Azimuth on the equator equal to the one not on the equator?

I am trying to fully understand the concept of Azimuth and I am encountering some inconsistencies (or maybe it is my error). I show you some examples that do not match, hoping somebody can explain me ...
366 views

### Air corridor in spherical surface: calculating great circle tangent points with small circles

I have the necessity to draw on a sphere (earth) an air corridor. In the cartesian plane, this corridor is made by some circles and from outer tangents that connect these circles as you can see in ...
983 views

### Geodesic measurements for short distances throughout US?

My ArcGIS experience has been limited to working on large-scale maps with planar projections. I'm moving to a project in which I want to calculate the distance between pro sports facilities throughout ...
646 views

### Buffer not providing accurate geodesic buffers in ArcGIS Desktop 10.0?

This appears to only be a problem when using ArcGIS Desktop 10.0. I created a shapefile following these criteria as recommended for Performing Geodesic Buffering: The input feature class must be a ...
1k views

### calculating bounding box from known centre coordinate and zoom

I have a map, the centre of that map (centrepoint) is = -37,175 ( gps) I know the zoom of the map = 13 I know the size = 320x320px I know there is 111111m in a degree of latitude and a varying degree ...
1k views

### How to compute geodesic area in GeoDjango?

I have some polygons which can be anywhere in the world. I would like to compute their areas. The GeoDjango docs for GEOSGeometry.area don't specify whether it is geometric or geodesic area, but ...
566 views

### Creating a Geodesic Polyline Buffer in OpenLayers

I have a feeling that the answer is going to be 'You can't do that without some very complex coding' but I thought I'd go for it anyway. I recently asked Creating Polyline Buffer in OpenLayers 2?, ...
1k views

### How to generate geodesic linestring from two points in C#

I'm looking for a FREE C# class, library or set of functions that will allow me to generate a geodesic linestring (or array of vertices, whatever) from two decimal degree points. I've found ...
638 views

### Are long lines in shapefiles to be considered geodesics or straight lines in the 2D latlong space?

Is there a definition on how lines connect vertices in the shapefile format? In the simplest case, imagine a line with only 2 points, from 40,-118 to 40,-112 - that's somewhere random in the US - ...