Angular geographic coordinates that specifying the north-south and east-west positions of locations.

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3
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2answers
57 views

Convert Lat/Lon Pair to Cartesian

I'm lost on how to correctly and accurately translate Lat/Lon coordinates to XY coordinates to draw them using OpenGL. The coordinate information I have is the following: Start Lon, Start Lat, End ...
0
votes
1answer
36 views

How to find a location is inside a country?

Given a Country Code and a Lat Lng pair, I want to find whether it is inside that country or not? What is the way to do it? Is there an algorithmic way to do this? I can accept certain amount of ...
1
vote
1answer
40 views

How to calculate the shortest geographical distance between a line and a point? [duplicate]

I'm trying to calculate the shortest distance between a line (described as a pair of [lat, long]s) and a point (lat, long) accurately. I've read many Wikipedia pages, but I'm new to the topic. I've ...
1
vote
1answer
64 views

Converting mercator meters without UTM zone?

I've been attempting to extract track information from Humminbird (Side Imaging Sonar) binary files and have hit a stumbling block with the coordinates it provides. The values are apparently in ...
1
vote
1answer
30 views

Locating Moon in Sky from Earth

I am working on project which need to find moon location from a specified lat, long on earth. So basically info I am having is Lat,Long and Timezone. Format of the moon location Info? So first in ...
0
votes
0answers
16 views

Pros and Cons of a latitude adjustment grid vs other methods of area calculations

When working with high resolution global raster data in WGS 1984 I often need to calculate areas. Now the traditional way for me to achieve this has been to reproject the data to an equal area ...
3
votes
3answers
124 views

Can a shapefile, or other file, be made from Excel without coordinates

I have two Excel spreadsheets I'd like to make into shapefiles, or some equivalent. I have access to ArcGIS at work and want to try using GRASS as well. I have seen the help on doing so, but only if I ...
1
vote
0answers
51 views

Convert polygon data into extreme lon/lat coordinates using QGIS

I'm very new to QGIS. I have a shape file of census blocks and want to use the data to plot points within each boundary using Google Maps api. I figure the best way to do this is to find the extreme ...
1
vote
1answer
40 views

Load feature class with tab delimited file that is missing Lat/Long

I am working on a Python script that receives a nightly tab delimited flat file. This flat file has Latitude and Longitude fields and the script loads the data using the gp tools Make XY Event Layer ...
1
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0answers
14 views

gdaldem slope attribute passing

How to pass slope attribute to the command "gdaldem slope manj.tif outpiu.tif -p use percent 45 -s 111120/370400" It's giving error like FAILURE: Too many command options. give any ...
1
vote
1answer
30 views

Adding a latitude/longitude graticule in CartoDB (e.g. WMS)

I'd like to add a basemap that has a graticule in latitude/ longitude to the Map View of a CartoDB project. This could be in the WMS format for example, but I haven't been able to find one that ...
3
votes
1answer
100 views

Creating .shp from .dbf in ArcMap?

How do I create a shapefile using the latitude and longitude information in my dBASE table? I am using ArcMap 10.1
1
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2answers
41 views

Cannot convert dms to dd in Excel 2007 using VBA code

I am trying to convert the data in an Excel sheet from dms (degree-minute-second) to dd (decimal degree) format using the vba script available here. Here is sample data: 53° 0' 39.31" 6° 44' ...
2
votes
2answers
91 views

Mercator: scale factor is changed along the meridians as a function of latitude?

"In Mercator projection the scale factor is changed along the meridians as a function of latitude" How to calculate the Mercator scale factor as a function of the latitude in decimal degrees ? ...
1
vote
1answer
50 views

How can I measure area in square kilometres from lat / lon gps coordinates?

I have code from openlayers that I cannot quite handle because I am so new for these kind of codes. My main goal is to measure area from n amount of lat/lon gps coordinates and convert the result into ...
2
votes
0answers
56 views

Lat Long to Useable values in QGIS

I am using both QGIS 1.8 and 2.0. So either is helpful. A client has given me locations of trial pits but i cannot load them into QGIS no matter how hard i try. For example, 50°24.711 North ...
1
vote
1answer
54 views

Are latitude and longitude independent of each other or correlated?

I want to develop a bivariate gaussian kernel in order to handle the random noise in my GPS tracks where each point has three parameters (lat, long and time stamp). I was wondering if latitude and ...
4
votes
3answers
167 views

Does the NED use geocentric or geodetic latitude?

What kind of latitude does the National Elevation Dataset (NED) use? Geocentric or geodetic or something else? I can't find the information anywhere on their site (http://ned.usgs.gov/index.html) or ...
0
votes
3answers
52 views

Calculate distance using 2 sets of lat/long values in the same record

I have a point layer with over 90K records in it. For each record I have lat/long field for incident, and lat/long for engine location. Is there a way to find the distance between Incident point and ...
7
votes
12answers
2k views

How do you memorize the meaning of longitude and latitude? [closed]

Longitude and latitude are concepts I usually don't need an then I sometimes suddenly need to learn their meaning for a period of time b/c I am using them. Is there an aide-memoire to finally ...
0
votes
0answers
36 views

Create global raster layer with latitude values of each cell in QGIS

I have a raster with a 0.0083 degree resolution (WGS 84) of which I need the area of every single pixel. An easy but compute-intensive approach is explained here but as I need to work with bigger ...
0
votes
1answer
35 views

Drawn figure looks stretched

I have written some code which offset a certain latitude and longitude with a distance in centimeters. What I am trying to do is based on a coordinate and a vector create two new points along the line ...
1
vote
0answers
42 views

How do I convert Lon and Lat to pixels in map using world file?

I have a tiff map file, with a tfw world file that has these parameters (lon/lat in radians): 0.00000107180145766 \\ A 0.0000000000 \\ D -0.0000000000 \\ B -0.0000009331315579 \\ E ...
0
votes
1answer
81 views

Postgis: Traslate geometry from EPSG:23030 to EPSG:21818, then to lat long

I'm from Colombia, South America. I'm a computer programming student and I have to develop a prototype for a GIS system for my small home town using Postgis >= 2.0 as database back-end. The local ...
0
votes
1answer
55 views

How can I get the circle of a sphere (on Earth ellipsoid) around a point using the Latitude and Longitude?

Specifically finding points along the circle. If possible without converting into Northing/Easting beforehand. I'm looking for the fastest possible way to calculate points in Latitude/Longitude in a ...
2
votes
1answer
105 views

What methods exist for geohash of polygon?

GeoHash is an excellent method to code the latitude and longitude of a point into a string. It's concise, due to the use of numbers + letters, and the precision can be tuned adding characters at the ...
0
votes
1answer
58 views

Bilateration using longitude, latitude

I have 2 coordinates (Longitude and Latitude) and a distance from them to a third coordinate. How is it possible to calculate the longitude and latitude (probably 2 possibilities) of the third ...
0
votes
0answers
40 views

50m x 50m grid around the world

I'd like to subdivide the earth into a grid of approx. 50 x 50 m cells (big database, I know). To make it more complicated (and fun), I also need to be able to determine to which cell a given set of ...
3
votes
2answers
779 views

What kind of coordinate system is this?

I have a csv with a list of the world sea ports and their coordinates. The coordinates are in this format: 5234N 00226W How can i convert this to decimal Latitude / Longitude ? Data source
1
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2answers
62 views

Compute the latitude of a center of mercator projection

Say I'm looking at a portion of a map that's displayed using Mercator projection with the view bounded at 40°N and 20°N. How do I compute the latitude of the point that's in the centre of that view? ...
0
votes
0answers
24 views

Find square with latitude and longitude for given lat and lng and distance [duplicate]

I have the coordinates of some point, lets say lat and lng, I want to find the latitude and longitude of top left and bottom right corners of the square, whose sides are located k kilometers from the ...
1
vote
1answer
349 views

Creating Longitude and Latitude Lines in Google Maps

I'm working on an independent high school project where i'm trying to build a simple differential equation model for diffusion. I'm trying to overlay the model on top of a map to visualize spread, so ...
0
votes
1answer
61 views

MYSQL 5.6 Cluster / chain points by distance to any other point without millions of calculations?

I have a table of approx 10,000 - 20,000 dynamic points across the globe stored as lon/lat points. I want to cluster any point within (roughly) 3km of any other point into one point (and return the ...
1
vote
1answer
48 views

Lat/lon of pixel inside Landsat scene

How do I find the lat/lon of each pixel inside a landsat scene. Either the equations for converting i,j to lat/lon or just a bunch of files, one for each scene. Background: I have downloaded a bunch ...
3
votes
1answer
71 views

Help identifying a coordinate system

I have some "latitude" and "longitude" data that describes the Silverstone motor racing circuit in the UK. The coordinates look something like this: latitude longitude +03124.27986 +00061.07652 ...
1
vote
2answers
200 views

Searching planet_osm_point by longitude and latitude

I used osm2pgsql to import data into my PostgreSQL database and it put gave me the following 4 tables, planet_osm_point, planet_osm_line, planet_osm_polygon and planet_osm_roads. I have looked at ...
0
votes
1answer
51 views

Get LatLng coordinates from SIRGAS2000 UTM 21s coords

I have a bunch of locations (36k) and they are represented using SIRGAS2000 (UTM 21s) coordinates. I need some way of converting them to traditional LatLng format so I can upload them to my database ...
0
votes
1answer
312 views

Extract Longitude and Latitude from Geotiff (ASTER 30m DEM)

my problem is apparently quite simple, but I cannot really find an easy answer: in QGIS I've created a raster layer by merging different GeoTiff images from the ASTER 30m DEM dataset. The merging is ...
1
vote
2answers
141 views

PostGIS to GeoJSON with GDAL: how to get lat/longs?

I'm trying to convert line features from PostGIS to GeoJSON files, as follows: from psycopg2 import * from subprocess import call conn = connect(dbname='gis') cur=conn.cursor() cur.execute("SELECT ...
0
votes
0answers
53 views

calculate distance between points crossing the antimeridian

How can I calculate the distance between two points (lon/lat) if any of the points exceeds the antimeridian (+-180 longitude)? Im using the distVincentyEllipsoid {geosphere} to calculate the shortest ...
0
votes
1answer
133 views

How to obtain the maximum/minimum longitude and latitude for a polygon?

I have the MSA/CMSA shape file which contains 274 metropolitan areas. How do I have to obtain the maximum/minimum longitude and latitude for an area? So, it's like drawing a box right outside and ...
2
votes
1answer
70 views

Decimal Degree data erases itself between edit sessions in QGIS

I have a shapefile with point data. I calculate the $x and $y of the points successfully I save the changes and close the edit session. Once I reopen the attribute table, the data after the decimal ...
2
votes
1answer
117 views

Compute the area of a given polygon (in vector format) lying between specified lines of latitude

I have species distributions (in vector format) and I would like to calculate how much of the area for a given species distribution is within certain lines of latitude, such as temperate and tropic ...
0
votes
0answers
40 views

Get tag/feature/landuse meta information for latitude longitude in openstreetmap

I need the possibility to find the underlying ground information of a given location (set by latLng) - not an area! I already tried the nominatim reverse search, but it lacks the landuse information. ...
0
votes
1answer
327 views

What is the format expected by QGis for Latitude/Longitude in DMS?

I have been struggling with a csv file I need to import into QGis 2.2.0 (on Windows 7). The coordinates are in this format: LATITUDE LONGITUDE 424605 861204 395222 861206 303051 861219 ...
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0answers
76 views

Ohio State Plane to Lat/Lon

I've looked into a few other posts/libraries as far as converting between State Plane (Easting/Northing) to get a Lat/Lon value, however I've run into some trouble. I saw here ...
1
vote
1answer
84 views

Reprojecting kml in NAD27, 83 or WGS84 using QGis

I have downloaded a kml file from Google containing location of shops. The coordinates in that file are in lat/long. I have other shp files containing roads and territories. I am trying to have all ...
1
vote
1answer
199 views

Converting lat-lon from degrees and decimal minutes to decimal degrees in PostGIS [duplicate]

Creating a geometry in Postgis is fairly simple: ST_SetSRID(ST_MakePoint(longitude,latitude),4326); These lat/lon should be in decimal degrees format like 33.02505 -96.70668 Is there a ...
1
vote
1answer
59 views

Census Block GEOid2 conversion to Latitude Longitude

My question is similar to this question. I have two different data files. Data1.csv (4500 rows) GEOid GEOid2 Total Population Urban Rural ...
0
votes
1answer
278 views

Convert some UTM coordinates to Lat Long

I have a series of UTM coordinates in an Excel file that I need to convert to Lat/Long. They are listed in the spreadsheet as "LONG(XUTM)" and "LAT(YUTM)". I know the coordinates are located in ...