Linked Questions

4 votes
1 answer

Why does not equal length of line in DIRECTION/LENGTH with length of line in MEASURING in OpenLayers 2.13? [duplicate]

My map projection is: "EPSG:900913", display projection is "EPSG:4326" and units is "m", however does not equal the length in Direction/length with the length is calculated in measuring in OpenLayers, ...
Samane's user avatar
  • 989
3 votes
1 answer

PostGIS: calculate area of intersection of EPSG:27700 polygons?

I have two tables in Postgres, both of type geometry(MultiPolygon,27700) and I would like to find any that intersect with an area of more than 100 square metres. I know how to get any that intersect ...
Richard's user avatar
  • 3,251
2 votes
1 answer

Area of an EPSG 27700 polygon

I am working with EPSG 27700 polygon data in PHP. All the polygons are in the UK. The polygons do not have holes inside them. I'm hoping to be able to calculate the area of these polygons. For this I ...
Christopher Gutteridge's user avatar
2 votes
1 answer

Changing projection for field calculator

I've just succeeded in getting the area of a polygon using field calculator. The polygon was drawn on a Google hybrid aerial photo. There are no units given in the calculation and I assume the area ...
otis_b_flywheel's user avatar
1 vote
1 answer

Choosing projection for calculating 2D 3D area in New Zealand?

I'm trying to use Surface Volume tool in ArcMap to calculate 2D and 3D area of a catchment. What would be the best projection to use and how do i check the maximum error of the estimation?
Jiajia Liu's user avatar
1 vote
1 answer

Getting geodetic area from rgeos::gArea? [closed]

I need to get an area of different polygons at continental scale (like third of Africa etc.). Usual functions like rgeos::gArea work only in the projection units. Is there any function which works ...
Tomas's user avatar
  • 1,191
0 votes
1 answer

calculating ratio of areas on a sphere

I have 2 shapefiles and after identifying their intersections I'd like to know the ratio of intersecting areas, e.g. a given shape S in file1 intersects with shapes (x1,...,xn) in file2 with ?...
Anna Magdalena's user avatar
0 votes
1 answer

What is most accurate Spatial reference system for calculate Area entire world [duplicate]

I want to know what Spatial reference system is most accurate to calculate area? I want to use it for entire world (-180,+180,-90,+90 area in WGS84 system) I have every thing ok I only need to ...
Majid Hojati's user avatar
0 votes
1 answer

Which area measurement to trust? - The same polygon in GoogleEarth v. ArcGIS [duplicate]

Possible Duplicate: What is the most accurate coordinate system for calculating areas of polygons? I'm currently involved in comparing the "official metropolitan" areas of several cities against ...
Wade's user avatar
  • 61
5 votes
0 answers

Intersection and area calculations in geographic vs. projected coordinates

I think one should do intersection calculations when layers are in the same coordinate system, and one should do area calculations in the appropriate projected coordinate system. The order matters, ...
JPC's user avatar
  • 71
3 votes
0 answers

Projecting polygon when calculating its area using R? [duplicate]

I have a broad range of polygons (in vector format and in SpatialPolygonsDataFrame class), some going east-west, others going south-north, while even others span polar regions or very large ranges as ...
jO.'s user avatar
  • 361
2 votes
0 answers

How to choose a projection for area measurement on building to continental scales?

I have many geographical objects described as polylines, polygons, multipolygons. All objects are in WGS84. Object could be: a building, stadium, park, street, highway, city, state, even country and ...
Capacytron's user avatar
1 vote
0 answers

how to calculate area if it is falling in two utm zones [duplicate]

I am using ArcGIS 10.1. How do I calculate an accurate area measure for a polygon, where portions of it are falling in two zones, i.e. UTM ZONE 44 & 45 (India)?
Kundan's user avatar
  • 11
1 vote
0 answers

What is the right projection for area calculation in Kenya? [duplicate]

I want to calculate the area of counties (1st admin level) in Kenya in ArcGIS. What is the right projection for that? I know I should use an equal area projection, but when I use them (I tried six ...
Enzo Baldini's user avatar
  • 2,217
1 vote
0 answers

Why Haversine formula and Web Mercator give different length between two latlng points?

I am calculating the distance between two points given by latlng. However, Google Maps (i.e., web mercator projection) gives me a longer distance than Haversine formula. Which is the most accurate ...
pedromateo's user avatar

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