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

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29
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3answers
9k 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 ...
19
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1answer
5k 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
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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?
14
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6answers
12k 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
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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
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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
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2answers
460 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
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1answer
602 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
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2answers
107 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
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4answers
8k 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
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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
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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
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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
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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
566 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
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2answers
233 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
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5answers
237 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
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1answer
95 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
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1answer
637 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
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1answer
629 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
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3answers
280 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
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1answer
663 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
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0answers
236 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
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1answer
188 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
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1answer
36 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
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1answer
792 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
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2answers
96 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
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1answer
104 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
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1answer
150 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
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1answer
100 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
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0answers
33 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
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0answers
27 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
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3answers
402 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
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1answer
270 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
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1answer
434 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
2answers
705 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
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0answers
124 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
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4answers
454 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 ...
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2answers
403 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
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1answer
825 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
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1answer
414 views

What is the best database for an online Android location app?

I am working on Android app for locating food places in my city. Using Google Map v2 api. App shows user his current location, and the closest food spots around him. I want to store location ...
1
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4answers
631 views

How to use GTFS data to create a Transit Route?

I am brand new to the General Transit Feed Specification (GTFS) stack and subway calculations and I'm working on a project where I need to tell a user what the best route / line to take based on their ...
1
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1answer
218 views

Android GPS: average location resolution time

What is the average location resolution time on a SmartPhone(Android) GPS? Assumptions : The user is under the open sky.
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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 ...
1
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1answer
54 views

How can I extract variable information from an OpenLayers 3 object?

I have tried to make a simple map with OL 3's Geolocation module. I succeeded with a resource wasting method. There must be a simpler way to extract variable information from an OpenLayers 3 object. ...
1
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1answer
95 views

How to convert distance into latitude + longitude [duplicate]

I have start point (latitude) I know direction, lets say strictly north, and I want to calculate latitude which is 100 meters above the start point. The same for longitude. I believe there should be ...
1
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2answers
365 views

Geo IP database for Brazil?

I am looking for a database that offers good accuracy for obtaining region from an IP address? Or, if this question is too fuzzy: Which one is (possibly) the most accurate? Note: I only need a ...
1
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1answer
149 views

I would like to show points moving on a map by date

I would like to create a map where i can see points moving. I have table of points for example with a date column, A 01/01/2012 B 02/01/2012 C 03/01/2012 D 04/01/2012 E 05/01/2012 F 06/01/2012 I ...
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1answer
28 views

How to calculate degrees per pixel in a given image? Or .nth of degree?

I am trying to make very rough estimates of Lat/Long coordinates in some random parking lot images. If I visit any such random parking lot on a Google map, I can click some driving area and Google ...