Geolocation is a means to discovering the physical location (in real-world geographic terms) of an object.

learn more… | top users | synonyms (1)

30
votes
3answers
10k views

Best GIS system for high performance web application - PostGIS vs MongoDB

I am working on a web/mobile application based on location data. Since i am already familiar with MongoDB, i found the geospatial indexing of mongo is quite suitable for my needs. As i am mainly ...
20
votes
1answer
7k views

Trilateration algorithm for n amount of points

I need to find algorithm that can calculate centroid A (aka gravity center, geometric center, center of mass) from the figure where circles T1,T2,T3,T4,T5,..,Tn intersect AND length of line R from ...
15
votes
9answers
4k views

How can I determine the location of a visitor to my website?

If I want to provide a website with location appropriate content, what ways can I use to find the visitor's rough location using their IP or header information?
15
votes
6answers
13k views

Is a Country/State/City Database available?

I asked this question Stack Overflow but I was informed that I would get a better to this question here because it's not related to programming. I am creating a directory which uses locations to ...
14
votes
6answers
2k views

What algorithm should I use for wifi geolocation?

School Pickup Use Case (update) It might be helpful to go into a more concrete use case instead of the original backyard example below. Local law enforcement has started cracking down on use text ...
12
votes
3answers
2k views

Calculating the distance between a point and a virtual line of two lat/lngs

Please refer to the example and corresponding image. I would like to achieve the following: provide two locations (lat/lng), which are shown below as A and B. From this, a virtual line would be drawn ...
12
votes
2answers
512 views

Propose a new location for Watch Tower using Viewshed Analysis

I want to suggest location for new watch tower in a forest area, but i am confused , on what criteria i can propose a best location. If i am taking DEM , slope and distance from existing tower , ...
11
votes
1answer
689 views

How much sense does it make to average (lat,lon) samples in order to increase 2D accuracy of a GPS location?

Several GPS applications, like this one, or this one, acquire multiple (lat,lon) samples of a given location, assuming that the GPS unit is not moving, and then take an average of the samples in order ...
10
votes
2answers
109 views

Where does one ask “Where is …?”?

On a fairly regular basis at my place of work we get inquiries of the form "where is Lake Potato?" or "where is Poppingstone Creek?" or... The questions come from co-workers, the general public and ...
9
votes
4answers
9k views

How to generate random locations nearby my location?

I am trying to create random locations nearby my location. What i want is to create random latitude/longitude pairs inside a 200 meters circle surrounding my location. This is the formula i came up ...
9
votes
1answer
98 views

How To Understand Geological Directions?

I was reading a "Guide to Some Minerals and Rocks in Indiana," which was published in the 1950s, and in it there were these bewildering directions: "Bluff along Mud Pine Creek 1.5 miles west of ...
8
votes
11answers
2k views

Device for Logging GPS and Accelerometer Data?

I am looking for a device that can track my location (lat,long) and speed all day long. Perhaps, I need GPS and accelerometer data bundled together. What I want to do is to log my daily activities. I ...
8
votes
3answers
1k views

What GPS device do I need for vehicle tracking?

I am a programmer with no connection to Geographic information, except that I work on application which uses google maps. So here is my problem. I need some device, which I will be able to set in a ...
8
votes
4answers
4k views

How does WiFiSLAM work?

Apple recently acquired WifiSlam. How does their technology work? Their website doesn't go into much detail. Allow your smartphone to pinpoint its location (and the location of your friends) ...
8
votes
4answers
614 views

Geolocation database of beaches

Anyone know where or how to obtain a database of worldwide beaches? Required fields are: name latitude longitude coastline aspect (if possible) Alternatively, is there a way to query Google Maps ...
7
votes
2answers
241 views

Is there a GIS to locate exact opposite locations on earth?

I was wandering if there was a GIS that offers to locate the exact opposite location of key locations (countries, even cities ?) on earth ?
7
votes
5answers
238 views

What technique is used to acquire client location?

So far I know how to grab the client location to a application or web application by using the users geolocation or GPS location. I remember the possibility of finding the users approximate location ...
6
votes
1answer
96 views

Dividing the world space to geographic sub-space

I am trying to divide the world space to geographic sub-space from "general" to "specific" locations and without using latitude and longitude information. That is, I am trying to think about the world ...
6
votes
1answer
700 views

Open source location allocation modelling

I'm looking for open source tools for location allocation modelling (eg planning public health facilities). Preferably in a GIS environment. I know GRASS somewhat, but v.net.alloc doesn't seem to ...
5
votes
1answer
713 views

Where can I find High Quality Road Network Information

I am carrying out a research on how complex city road networks get and I need to get accurate map information. I started with openstreetmaps however I ran into a couple of issues: some of the dumps ...
4
votes
4answers
3k views

Calculate distance of point from an arc/polyline

Using Postgres/PostGIS, I am trying to query the database for the closest arc to a particular GPS point. Each Arc is made up of two nodes that are GPS points on a map. Is there a way I could query ...
4
votes
3answers
291 views

EPSG geotiff code and crs us48

I am trying to create a geotiff and the software (raster design) is asking for a code that I thought was EPSG code. however while trying to find out what epsg = us48 I noticed that the dialog actually ...
4
votes
1answer
757 views

Probability of iOS/Android device location accuracy

I'm working with Android and iOS apps that report location. Both iOS and Android can derive location from a combination of cell tower triangulation, visible wifi access points, and assisted GPS. The ...
4
votes
0answers
258 views

Translate Orientation from Sensor data to Geo location

I am tracking a device that might loose GPS signal then and there. And when the GPS signal is too low, I should use the accelerometer and Gyroscope sensors data to guess which way they should have ...
3
votes
1answer
189 views

Worldwide places reachable by sea/ocean

I'm looking for a list of all populated places(not just big cities/ports) on the world that reside on sea/ocean. The list should contain the place name, latitude and longitude. Does something like ...
3
votes
3answers
193 views

Display millions of points in the browser

I have a web application which will track he movement of user, and save the history location to database. And user may want to see his/her movement trace over a period of time, we have to display ...
3
votes
1answer
123 views

Best Practice for HTML5 Geolocation with ArcGIS for Javascript API

My organization would prefer to use its own basemaps rather than those provided by ArcGIS Online due to the accuracy of information that is represented in them. The area we service is rapidly ...
3
votes
1answer
909 views

How to calculate midpoint given north/south latitude and east/west longitude?

First, sorry if this questions sound very simple. I am very new to GIS. Given four values of north/south latitude, east/west longitude how to calculate the center point that is correct for all cases ...
3
votes
2answers
98 views

Where can I find a map with the location of towns and cities in Southern Sudan?

For a project I have some name of towns and cities in the Southern part of Sudan, the region South Kordofan. Many of these towns I can't find on Google Maps, but I need to know their location. ...
3
votes
1answer
105 views

Looking for HowTos or Examples of Presentation Platforms targeting Management/Clients

Any good ideas about using Google Earth to present self contained geospatial data&app to a client or senior management? The broader issue being explored here is that many of our clients are not ...
3
votes
1answer
255 views

Mastering Geo Locators in ArcGIS 10.2

We just moved from 10.0 to 10.2 and woke up to the wonderful news that all our geolocators are broke and need to be recreated. Most were made in 9.3. This is fine, but the locator building process has ...
3
votes
1answer
102 views

Is there a way to get the method how the location was processed?

Experimenting with the W3C Geolocation API. Is there a way to get the method how the location was processed? I mean GPS, IP, Cell IDs etc. I didn't find any object properties doing that. Thanks!
3
votes
1answer
40 views

Create Archimedean spiral with geographic coordinates

I don't know if this is the right place to ask but here it his. I want to create an Archimedean spiral based in some location. Lets say I have this set of geographic coordinates (48.860770, ...
3
votes
0answers
28 views

Python Geolocation Software to Filter Cities By Population Within a Radius?

What I'm trying to achieve I want to enter a US city/state or zip code value. Then enter a radius (ex: 30 - would stand for 30 miles). Then I enter a minimum population (ex: 100000 - would tell the ...
3
votes
1answer
41 views

extracting geographic location from NOAA NARR grib

I've downloaded a NOAA NARR grib file that I want to extract the wind component as well as the geographic location. I'm able to extract the wind component from the grib but I can't seem to find any ...
3
votes
0answers
149 views

Downloadable, Open Source, IP GeoLocation database

I have an open source project I need a similarly open source IP GeoLocation database for. i.e. IP address to country (and ideally city). Ideally with a license that allows redistribution. This is a ...
3
votes
0answers
29 views

Algorithm for estimating position of many objects and differentiating those?

Let's assume a crowd-sourced tree location use case where a research team asks hikers to GPS the location of a specific tree type in case they encounter it. This will lead to a large number of ...
2
votes
4answers
584 views

Offline Python or C++ library for plotting locations on map?

I'd like to plot locations using longitude and latitude coordinates using Python or C++, is there a good library for such a task? I know that matplotlib is an option, I'm wondering if there are any ...
2
votes
3answers
435 views

GPS and GIS for real time monitoring of an object

How is it possible to store coordinate of object in server in real time using feasible hardware ( can be used by student) GPS into database and retrived in real time?? What are the names of ...
2
votes
2answers
750 views

Reading MODIS L1B into ENVI

I am working with MODIS Terra (and simultaneous ASTER) Level 1B swath data using ENVI and am having one of these "this should be easy" questions about the most direct way to get to geo-referenced ...
2
votes
1answer
36 views

Randomly distributed cases according to census data

I'd like to randomly place a point within a geographic boundary with the caveat that I would like to use census data so that points are randomly placed according to population density (i.e. more ...
2
votes
1answer
284 views

Why does Updating Location of ArcSDE Feature using ArcObjects .NET give Error HRESULT E_FAIL has been returned from call to COM component?

I have been able to connect to an Enterprise GeoDatabase, retrieve features from it and update attributes. However I am having problems accessing and then updating the shape property of a feature. ...
2
votes
1answer
466 views

Openstreetmap - retrieve nearby big cities for a given location

I was wondering how I can retrieve places near a given location? For example, if I pass the osm API the location "Paris" is it possible to retrieve all the main biggest cities around Paris within a ...
2
votes
0answers
23 views

Looping a location-allocation problem in ArcMap's Model Builder

I have developed the model below in which I iterate through a series of values for a variable in the Location-Allocation type of problem. The variable is the number of facilities to solve. The model ...
2
votes
0answers
26 views

Location API works, but neither Google Maps, not Here maps can not find location

I used Holux M-241 as GPS receiver. On Windows 8.1 I installed GPSDirect drivers, and now can see my location on PC. I tested that Location API can access to gps data (I used this Mozilla Developer ...
2
votes
0answers
131 views

Geolocate stores inside a mall?

OpenStreetMap lists the malls in Albuquerque, but not the stores inside these malls. Using the in-mall map/directory, wouldn't it be easy to add stores inside the mall? Is anyone doing this? ...
1
vote
2answers
560 views

Socket Server to receive GPS location data

I am working on a web application which receives data sent from trackers via TCP Packets containing location information. Up until this point we have been working with dummy data within the mysql ...
1
vote
2answers
53 views

Data of worldwide shore lines and bathymetry

Please excuse my probably naive questions because I am new to this stack exchange. Is there a free database with all geolocations for shorelines? Is there a free database for near-shore bathymetry ...
1
vote
1answer
936 views

add a feature in openlayers using lonlat from geolocation

I'm trying to add a feature in a openlayer's vector layer using the lonlat that came from the HTML5's geolocation API. Combining tutorials for the geolocation and this demo I created the following ...
1
vote
1answer
33 views

Save millions of points in the server side

I have asked a similar question about millions of points a few days ago:Display millions of points in the browser. It focused on how to display these data in the client(browser), however I think it ...