Tagged Questions

Longitude is a geographic coordinate that specifies the east-west position of a point on the Earth's surface.

learn more… | top users | synonyms

37
votes
2answers
16k views

How to measure the accuracy of latitude and longitude?

I am very new to GPS stuff. Suppose I have latitude and longitude as 19.0649070739746 and 73.1308670043945 respectively. So now both co-ordinates are 13 decimal places long. But sometimes, I also get ...
29
votes
3answers
4k views

LatLon or LonLat, what's the “right” way to display coordinates and inputs?

I'm trying to get a sense if this is an issue for others or every input/output should be labeled so user is not confused and just go with it? I think almost everyone pronounces it as "LatLon". Who ...
16
votes
3answers
570 views

Why do we use the terms “longitude” and “latitude” for a spherical body?

To specify a geographic coordinate we use the terms “longitude” and “latitude”. Far as I know, these terms derive from the Latin latitudo (= breadth) and longitudo (= length). In German we use the ...
12
votes
2answers
371 views

How do you find a lat/lon (DMS) on a paper map using a 30cm ruler?

How do you use a 30cm ruler to find DMS on a paper map? The locations I would like to find are the 'corner' points so I can generate an extent based on the four corners. I have an old paper map (3 ...
11
votes
2answers
1k views

Why latitude/longitude and not the other way round?

When you google "latitude/longitude" you get 10 times more results than "longitude/latitude". This I find very confusing as "x/y" seems 20 times more common than "y/x". But on a map Latitude is on ...
10
votes
2answers
1k views

Lon/lat transformation

First I should clarify I don't have previous experience with the field, so I don't know the technical terminology. My question is as follows: I have two weather datasets: The first one has the ...
8
votes
1answer
158 views

Great-circle lines in Equirectangular projection

Just to check that I'm on the right track: Are all great-circles on the sphere and in equirectangular projection (i.e. latitude, longitude pairs) either: meridians (i.e. going pole to pole) of the ...
8
votes
3answers
2k views

Computing an averaged latitude and longitude coordinates

How can I compute the average between several latitude and longitude spots ? Should I just compute the Arithmetic mean for both lat and lng ? thanks
8
votes
1answer
966 views

How to compute the bounding box of multiple layers in lat/long?

I am writing an application to performance test all kinds of map services, primarily AGS 9.x, AGS 10, and WMS 1.x. Part of the application involves generating random bounding boxes for individual ...
7
votes
3answers
528 views

Longitudinal Issues with NetCDF data

I am seeking advice on working with world data sets where the GCS has a positive range (0 degrees to 360 degrees). The data I am working with are NetCDF oceanographic data and have positive coordinate ...
6
votes
1answer
147 views

locating latitude-longitude point in a piste-map with matrix transforms

I am trying to plot points of a particular latitude longitude on this image of a Swiss mountainous landscape. What I am doing is I have some 54 known location-points plotted on this image (not ...
5
votes
2answers
260 views

What is the origin of the Degrees, Decimal Minutes format?

In my experience, for most non-GIS folks, the most commonly used and understood coordinate system is good old Latitude and Longitude, displayed as degrees, minutes, and seconds (DDMMSS.ss). In GIS, ...
5
votes
1answer
114 views

How do I georeference a ski map?

I have a map of a mountainous landscape, http://skimap.org/data/989/60/1218033025.jpg. It contains a number of known points, the lat-longs of which can be easily found out using google maps. I wish ...
5
votes
1answer
268 views

How can I programmatically open an OnPoint map to specific coordinates?

We have an OnPoint server at work and I'm wondering how to open the mapping service and having it zoom in to my specified latitude and longitude. The reason I ask is because we have an application at ...
4
votes
3answers
214 views

Canadian province boundaries in latitude and longitude

Are there any datasets available that give a list of latitude and longitude points for Canadian province boundaries? I don't need anything too detailed as I'm displaying collated data in smallish ...
4
votes
1answer
206 views

Problems with lat long projection

Hi this seems like it should be an easy problem, but its been giving me a headache. I have a .xls spreadsheet with about 60,000 rows. Most of them have Latitude and Longitude. I simply want to ...
4
votes
2answers
183 views

How to extract values from a raster according to Lat and long of the values?

having 12 files with 12 hdrs for one year: these files are raster (projected WGS84,lat long):https://echange-fichiers.inra.fr/get?k=rLSyoavrnifGyH5XrlO samples = 1440 lines ...
4
votes
1answer
30k views

Does Y mean latitude and X mean longitude in every GIS software?

Now it's been 3 days I am using Mapinfo and it has Y as latitude and X as longitude. Is that the same case for all mapping software? As for any country their respective value is multiple of 1 or -1. ...
4
votes
2answers
376 views

Converting Geocentric to Geodetic

I am only looking for a confirmation of what I believe to be true. If my explaination or conclusion is not accurate I would appreciate it if the reason can be explained to me. Background ...
4
votes
1answer
1k views

How can I render latitude-longitude coordinates on a map with D3?

I am trying to overlay dots of arbitrary sets of longitude-latitude coordinates on top of a United States map. So far I have found the D3 cartography example, but when I try to place dots on X,Y ...
4
votes
1answer
79 views

Display XY Format to Shapefile (Scale)

Using ArcView 10.1 and using excel for Lat/Long conversion to a shapefile. The original Lat/Long has 7 numerical characters past the decimal point xx.1143717. When I convert this excel into a ...
3
votes
1answer
75 views

Which of these is the proper convention? [duplicate]

Possible Duplicate: Difference between lon and lng I run over these three abbreviations: "lat/lon" "lat/long" "lat/lng" Are they equal?
3
votes
2answers
249 views

Can one hide the Lat/Lng information sent to Google maps?

most services that use google maps have the Longitude / Latitude stored in the source to be sent to google maps to render their markers. However on this site (sorry Chinese) ...
3
votes
1answer
76 views

East North Format

I have a database with a list of address and their location as an East and North coordinate. An example is: East=431833 North=336684 Postcode=DE22 4LF When I try to convert this address using this ...
3
votes
2answers
510 views

How to calculate how long an arc second is for a given long/lat?

The title says it all, really. I am wondering what area is covered by a dataset which is one arc second wide. Thanks, Rob
2
votes
3answers
115 views

What Danish position format is this?

I have been given a list of locations within Denmark. Most of the are in decimal degrees. However, some of the positions are in different formats and I can't figure them out. Does anyone recognize ...
2
votes
2answers
1k views

Problem when calculating longitude and latitude for points

I have a PostGIS database with SRID=900913 (Google Mercator) and I would like to know the latitude and longitude of points. I use this command: ST_X(ST_TRANSFORM(the_geom,4283)) Following what is ...
2
votes
2answers
211 views

How to avoid exceeding latitude and longitude limits, when importing a .csv file?

I am currently working with a project with "on the fly"-projection (WGS 84 / UTM zone 32U). Now I want to import a csv. file with points, which have a longitude and latitude using the "Add Delimited ...
2
votes
1answer
165 views

WGS84 - how to convert

I have multiple locations saved in WGS84 - it looks like e.g. latitude: 12345678 longitude: 87654321. I tried to search it on the map this way: 12.345678 87.654321, but it doesn't match the place it ...
2
votes
1answer
210 views

How can I get the corners of a polygon in latitude and longitude?

How can I get the corners of a polygon -a square/rectangle, to be precise- in latitude-longitude format by using its geom value -or some other way, perhaps-? Thanks.
2
votes
1answer
249 views

Getting zone from UTM in order to convert to latlong

I am trying to convert UTM to a latlong point. To get that done I need to know the zone where the UTM coordinates are. how can I find the zone from UTM?. the place coordinates that I work on lay on ...
2
votes
2answers
1k views

How to convert geometry coordinates into Google lat/lons?

For storing geospatial data, the geometry field is used in SQL Server or Oracle Spatial. I want to know is there any way where we can convert this geometry field into a set of latitudes and ...
2
votes
3answers
159 views

Looking for a fine U.S. Latitude and Longitude grid (0.25, 0.5 degree)

There is a global latitude and longitude grid data available at 1 degree resolution and higher (http://www.arcgis.com/home/item.html?id=f11bcdc5d484400fa926dcce68de3df7). Is anyone aware of a finer ...
2
votes
1answer
65 views

Representing degrees between -1 and 0 in Degrees:Minutes:Seconds

When representing latitude and longitude in degrees, minutes and seconds, with -180 <= D <= 180 (or -90 and 90) 0 <= M < 60 (0 if D is at an extreme) 0 <= S < 60 (0 if D is at an ...
2
votes
1answer
68 views

Need software to read geo information from tif

I am trying to verify the lat/lon and ECEF values that I have determined for a very specific and unusual situation (a geotif file), and it would be great if I could find some software to read them. ...
2
votes
3answers
1k views

Income data on a block level: how does a newbie do it?

I am a complete newbie at GIS data, and am trying to do the following: Figure out census blocks in Miami-Dade (and several other counties) that have average household incomes > $75,000 Get the ...
2
votes
1answer
109 views

Trilateration 3D - Vincenty's Formula

with reference to Trilateration using 3 latitude and longitude points, and 3 distances. The accepted answer was votes as shown in wikipedia at: http://en.wikipedia.org/wiki/Trilateration in ...
2
votes
1answer
159 views

How to georeference using Latitude and longitude in QGIS?

I'm trying to georeference a picture using Latitude and longitude. The points are these: top-left: (116.30950927734372,39.970805680527725) top-right: (116.35620117187497,39.970805680527725) ...
2
votes
1answer
380 views

How to determine maxResolution and numZoomLevels in dynamic environment?

I want to determine resolution and number of zoom level dynamically instead of inputting the values in openlayers client. When the user move the position on map by dragging or panning control, I can ...
2
votes
0answers
100 views

calculating bounding box from known centre coordinate and zoom

I have a map, the centre of that map (centrepoint) is = -37,175 ( gps) I know the zoom of the map = 13 I know the size = 320x320px I know there is 111111m in a degree of latitude and a varying degree ...
2
votes
0answers
86 views

how to convert lat and longitude into distance near poles?

I am trying to convert latitude and longitude into meters in polar regions. I am looking for higher accuracy upto 0.00 meters preferably. I tried the haversine formula but it doesnt seem to be ...
2
votes
0answers
190 views

Convert Lat/Long to UTM specifying which zone to use (Java)

I have a set of coordinates in decimal degrees spread across two UTM zones in my Java application that I want to export to use in Petrel, so they need to be in the same UTM zone. Is there a java ...
1
vote
2answers
692 views

shape file coordinate system

I added a shape file of Iran to Qgis. 'Tehran' has 35.6833° N, 51.4167° E coordiantes, however Qgis shows Tehran with 4772860,31296767. How i can view coordinates of a city or location in latitude ...
1
vote
1answer
194 views

Converting a shp file to a list of latitudes and longitudes

I have a shp file with the latitudes and longitudes for the boundaries for various geographic regions. I'd like to convert the shp file into lists of just latitudes and longitudes for the regions. ...
1
vote
2answers
124 views

Get All Records 60 Degree North in SQL with query on Lattitude-Longitude Column?

i have table with latitude & longitude columns in sql. how can i select all records with lat-long 60 degree north> ( Arctic Region ) Thanks Pragnesh
1
vote
1answer
75 views

find euclidean distance in GPS [duplicate]

i need to find the distance between two gps location, So i think to do this: lat1(seconds)-lat2(seconds)=lat * 30.7151 == distance latitude in meters =Latm long1(seconds)-long2(seconds)=long ...
1
vote
1answer
146 views

Lat Long line intersecting with circle

Can anyone help me what's the algorythm to calculate points of intersection whet is given one point p1 [lat,long] , bearing x (let say 137 degrees), arc center [lat,long] and radius? I woulde like to ...
1
vote
1answer
99 views

Accurate and fast nearest neighbour, which distance function should I use and how to it speed up? [duplicate]

I am solving the following problem: I have a map with many points in it and I need to find the nearest point to given location. Each point carries information about it's latitude and longitude. This ...
1
vote
2answers
493 views

How to make distance calculated using Latitude and Longitude more accurate

I'm coding a Web App whereby users can choose their city (start) and a destination city, and find out the approximate distance between both cities, using Latitude and Longitude of both cities to ...
1
vote
1answer
631 views

How do I calculate ECEF X,Y,Z velocities for GPS if I have no satellites

I'm attempting to simulate a GPS message where know variables are starting location, ending location, speed (m/s), and a bearing (0 - 359 degrees). How can I calculate the ECEF X, Y, Z velocities ...

1 2