Linked Questions

4
votes
2answers
54k views

Precision of x decimal points in meters? [duplicate]

Is there a handy reference that corelates the number of decimal points in a coordinate to the precision in meters? I had discussions like "4 decimal places will place you within a 500 meter radius" ...
3
votes
0answers
265 views

Decimal degree coordinates: how many decimal places to use for …? [duplicate]

When using coordinates in decimal degrees, how many decimal points actually make sense? For example, say one is producing a table of locations of base camps in a report, there's no point in ...
1
vote
0answers
190 views

Converting DMS to decimal degrees, what precision? [duplicate]

I'm working on a piece of software that converts Lat & Long from DMS (35° 19′ 20″ N) to decimal degrees. At the moment, the code creates number with 16 digits after the decimal point, which seems ...
1
vote
0answers
166 views

Degree Precision vs. Length [duplicate]

https://en.wikipedia.org/wiki/Decimal_degrees I found this chart in one of the questions here. Additional to this: When making a measurement and getting 2 Measures of Latitude, for example 51....
1
vote
0answers
143 views

Is there a standard as to how many meters or feet if a GPS number (latitude and longitude) is off by a tiny amount, such as 0.0001? [duplicate]

For example, if the latitude and longitude is 25.1054, 121.5973 then what if it is off by a small amount, such as 0.0001: 25.1055, 121.5974 Then can it readily tell how many feet or meters it is ...
0
votes
0answers
130 views

How can I tell the accuracy of coordinates conversion by cs2cs? [duplicate]

For example, when I try this: cs2cs +proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs +to +proj=tmerc +lat_ 0=22.31213333333334 +lon_0=114.1785555555556 +k=1 +x_0=836694.05 +y_0=819069.8 + ellps=intl +...
30
votes
7answers
11k views

Calculating intersection of two Circles

I'm trying to figure out how to mathematically derive the common points of two intersecting circles on earth's surface given a center Lat/Lon and a radius for each point. For example, given: Lat/Lon ...
30
votes
1answer
36k views

What is the precision of Geohash?

I would like to know the precision of a Geohash with a given length. If there is a 'simple' formula you can use to calculate it, that would be extra-cool. Wikipedia lists the precision up to 8 ...
14
votes
1answer
50k views

Converting geographic coordinate system in R

I have points in geographic coordinate system and I wanted to convert them to swiss grid (CH1903+). Sample data: id lon lat 2 7.173500 45.86880 3 7.172540 45.86887 4 7.171636 45....
1
vote
1answer
73k views

display latitude and longitude on googlemaps on click

I am trying to retrieve latitude and longitude values. When the user clicks on the google map, latitude and longitude values should be displayed in the text boxes. My code is: <%@ Page Language="...
4
votes
3answers
29k views

Converting from an x-y coordinate system to latitude/longitude

I'm building an indoor wifi-based tracking system that can calculate the position of a device in meters relative to the sensors distributed throughout the building. So far I've gotten to the point ...
5
votes
2answers
19k views

How to calculate new point coordinates from distance and angle using ArcGIS SDK for iOS?

I want to calculate the coordinates of a new point. What I have: The source point coordinates, the distance (meters) and the angle For example: I want to create a point within 100 meters and 45 ...
2
votes
3answers
7k views

Local Coordinate to Geocentric

The ultimate question, I need a transformation matrix to take a point in local space representing a roughly 500m x 500m place in New Mexico centered at -108.619987456 long 36.234600064 lat. The final ...
2
votes
5answers
10k views

Reducing size of KML file (after converting from Shapefile)

I have a shapefile of size 224 MB. I am using ArcGIS to convert it to a KML file. The process involves converting the shapefile to a feature layer and then converting the layer to KML. An ...
11
votes
3answers
1k views

How to anonymise a gps file?

Imagine you have a GPS trace that you want to make anonymous, in the legal sense. How would you do this? Is snapping to the nearest x distance and stripping out the time enough? Are there ...

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