Linked Questions

29 votes
6 answers
16k views

I have data that spreads across two UTM Zones GDA/MGA94 UTM Zone 55 and 56. I have layers such as a cadastre, roads, pipelines etc where I want to store measurements like lengths and areas in metres ...
Ando's user avatar
  • 3,039
34 votes
1 answer
9k views

A Tissot Indicatrix is useful method for communicating at a glance the kinds of distortion a given projection is prone to (in the figure below, each of the red circles occupies the same area). I've ...
matt wilkie's user avatar
  • 28.3k
9 votes
3 answers
6k views

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 ...
XNSTT's user avatar
  • 438
9 votes
1 answer
2k views

I am trying to calculate distortion of an equirectangular projection via Tissot indicatrices. I have tried following the directions on this post (among other things) but it is beyond my understanding ...
NCashew's user avatar
  • 375
4 votes
3 answers
8k views

I get some GPS results which lay in China with WGS84 coordinate system, and I need to choose a projection to reproject for. First I chooses the UTM projection, but I find the results lay in ...
billycat's user avatar
  • 311
5 votes
2 answers
2k views

I've been working in GIS for about a year and have a functional grasp of Projections and Transformations from within ArcGIS (10.0). Geosoft Oasis is another program we use. In working with our data ...
TSJ's user avatar
  • 3,452
1 vote
1 answer
3k views

Does anyone know how accurate geodesic measurement is compared to planar measurements in UTM WGS84 for distances below 15km? We'd like to inform our users about measurement accuracy when using tools ...
ateko's user avatar
  • 145
5 votes
3 answers
363 views

I want to convert a square polygon that is close to the edge of UTM zones 15N and 16N. The polygon's coordinates are in UTM 16N, but it is spatially positioned in the UTM15 area. My question is that ...
Blind squirrel's user avatar
2 votes
1 answer
867 views

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
0 votes
0 answers
1k views

I am new with GIS. Assume we use the UTM30N coordinate system. Is it possible to calculate an area (say a square box) by the 4 given points? (assume the points are in order, and the coordinates are ...
Bill's user avatar
  • 111
2 votes
2 answers
1k views

I am planning on conducting a multi-criteria-analysis with a number of different source datasets. A number of the datasets are found in different coordinate systems and projections. Do I need to ...
rgmrtn's user avatar
  • 215
2 votes
1 answer
725 views

I'm trying to determine if an Albers Conic (Alaska Albers) is suitable as a projection for a corridor 800 miles long by 50 miles wide, that goes from the north coast of Alaska to the south coast. ...
user20882's user avatar
1 vote
2 answers
862 views

I have chosen to use a Web Mercator projection system for: Use of Tiling system for low memory usage Accessing only one site/area at a time Reuse of Google Tiles - for many sites In some cases I will ...
Kind Contributor's user avatar
2 votes
1 answer
409 views

I am writing a program which will find all the points within 1km. I am planning to to do this on a Euclidean plane as my database only supports Euclidean plane or sphere indexing (http://docs.mongodb....
user2924127's user avatar
1 vote
0 answers
289 views

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