3
votes
2answers
48 views

Why orthographic projection has been used in this NatGeo map

I'm wondering why this maps uses orthographic projection, and result is 3 maps to view the whole world, what were the requirments or the reasons to choose this projection (why not mercator ) ? this ...
0
votes
1answer
48 views

How to calculate point from lat/long, angle, and distance? [duplicate]

I am trying to calculate the point from a given lat/long, a bearing, and a distance. This is for plotting weather given a aeronautical way point. For example: Given a waypoint with a known ...
2
votes
2answers
72 views

which map projection should be used for global map with geography and human demographics

I am working on a project to try to identify the most threatened populations (on a global scale) of having a limited access to freshwater. I want to compare those most at risk currently and then add ...
1
vote
1answer
64 views

My class using ogr to calculate distance is returning incorrect results away from the equator

In an answer to this question ustroetz kindly provided some sample code for use of ogr to do lat/lon distance and point in polygon calculations. I've created a Python class based on his example to do ...
2
votes
1answer
50 views

Is there general Earth Projection in ArcGIS for Desktop?

I'm starting a new personal project and I need a little bit of helping on setting it up. First off I'm trying to determine the area of a rectangle that is 1 mile in width and the circumference of ...
-2
votes
1answer
67 views

Buffer is giving me a different distance [closed]

I'm using ArcGIS 10.1. When I Buffered I changed the environments to compare the two different projections. WyLAM is a statewide Lambert Conformal Conic projection used for Wyoming. State plane in ...
3
votes
1answer
113 views

Which projection is being used in this figure?

I would like to use the projection being used in this figure. Does anyone know which one it is? Esp helpful if it is available in ArcGIS. From plant stress page thanks!
2
votes
2answers
68 views

Measure areas, lenghts in specific regions (Australia, Sout East Asia)

I'm in need to find a suitable projections to measure correctly areas and lenghts for 2 areas of interest. I want to measure both factors for: 1) First region Australia & New Zealand (1st ...
0
votes
0answers
92 views

Lambert conformal conic projection - Europa

I am trying to calculate map of Europa in Lambert projection. I am using formula from wikipedia (Lambert wiki), but calculation is verřy slow with comparison to Mercator. I know, there are sin, cos, ...
1
vote
1answer
25 views

Network segment gaps, when offset

I'm having an issue when offsetting a line shapefile. For some reason when the lines are offset, ArcGIS isn't drawing some segments although the segments are there confirmed via “identify”. Has ...
0
votes
0answers
108 views

Map doesn't show anything in img file (WMS-Mapserver)

Actually in a practical Project we wanted to use OpenLayer and MapServer to display our data using WMS, but We can't find a proper srs or EPSG code. One of the ITC students said, we have to change our ...
8
votes
3answers
630 views

Distance measurements across UTM zones: use geographic or planar approaches?

I have a survey grid spread across 3 UTM zones (36N, 36S, 37S). I want to find the nearest (or shortest) distances of the centroids of these grids to roads and various points between. It seems like ...
1
vote
4answers
375 views

What projection to use in ArcMap for a map that extends over Wgs84 Utm31 and 32

Please i have a Wgs84 Utm map that extends over 2 utm zones(31N and 32N). Using either of them distorts my map and ArcGIs allows you to choose only one projection per map. Please what can i do? Thank ...
3
votes
2answers
348 views

High Resolution Sinusoidal Interrupted Projection of the Earth

My grandfather built a rather large globe 10 years ago and never got to complete it (he started drawing about a fifth of it by hand and just gave up after that). I have been looking for a sinusoidal ...
7
votes
2answers
624 views

Is the quadrilateralized spherical cube map projection the same as Snyder's cubic equal area map projection?

Is the quadrilateralized spherical cube map projection [1] the same as Snyder's cubic equal area map projection [2]? I know both are equal area polyhedral map projections ( ...
8
votes
2answers
367 views

how to produce a Peirce quincuncial map?

As far as I know neither PROJ4 nor ESRI tools can apply the Peirce quincuncial projection. Does anybody know what libraries/softwares can manage it?
10
votes
2answers
749 views

How to create an Azimuthal Equidistant map for long-distance radio?

I'm trying to produce world or continent scale maps that use the Azimuthal Equidistant projection. I'm a radio amateur, and to an antenna, the whole world looks like spread out on a flat plane, with ...
45
votes
8answers
2k views

One dimensional map of the world?

Bit of a strange question but hope this is OK to ask here. Has anyone heard of a '1-dimensional' projection of the world map - that is mapping all the points on the globe to a single line? I was ...
6
votes
4answers
6k views

How to reproject base layers in OpenLayers?

The issue is: I have vector/topo/image tiled maps for some places in north america which were published as ArcGIS Server REST service. These maps (A) are based in EPSG26912 projection. Now I wanna ...
38
votes
4answers
5k views

Why has Web Mercator (auxiliary sphere) become the web map standard?

I understand what the difference is between the Web Mercator projection and Web Mercator Auxiliary Sphere (WMAS). I also understand that both Google and Esri have adopted this projection as their ...
3
votes
0answers
1k views

Converting projected coordinates to google maps pixels

I have a single polygon in a local projection system. I would like to convert that polygon into an image that can be used as an overlay on google maps. I understand that it may be better to use ...
0
votes
1answer
365 views

How to point out a city from a map image of world with longitude and latitude?

have a map image 800px wide. How can I figure out a city. like New York has 40.75 latitude and -73.98 longitude. I have to pin a mark over this point. Before I have done with x_axis and y_axis which ...
7
votes
2answers
430 views

Why are there both square and rectangle world maps?

When i search for images of earth divides to longitude ans latitudes seems that the are 2 major types: is a perfect square and the latitudes in it are grow a different rate from the equator to up ...
2
votes
2answers
713 views

albers projection to Lat, Lon

Thanks in advance for helping me with my issue. This GIS stuff is using parts of my brain that have remained idle since high school, and some parts are working faster than others. I have land data ...
9
votes
4answers
684 views

World map projection with United States in center

I am creating a map showing flight paths originating in the United States and traveling to Asia and Europe. I need a projection for the world that will focus the United States in the center of the ...
19
votes
9answers
2k views

Discontinuous or Interrupted map projections?

Do any of the current open source GIS softwares support discontinous projection systems? E.g. sinusoidal, dymaxion, butterfly, etc? If not, are there any affordable commercial ones that do (affordable ...