I try to know why when I use the geolocation with differents browsers on a same computer I have differents results. I know the implementation of the feature is not perfect..but,
it's strange because I try on a computer with chrome and FF4.1 and i got a good accuracy. On the same computer IE give me a bad accuracy. When I try on an other computer with chrome and FF 4.1, Chrome give me a good result and firefox the same bad accuracy as IE (ip location i guess ).
If anyone have a solution to get the same accuracy for all browser or just an explication ?
Let's assume the location is computed using Google Street informations (wifi hotspots and cell phone repeaters).
For wifi, the geolocation module looks at signals received by the wifi adapter. Those signals are emitted from wifi access points. Google cars assessed the emission power of each access points, as well as their location, when driving around. From the relative strength of the signals received by the user wifi adapter, which is available to the geolocation module, the location of the wifi access points in sight, and their assumed transmission power, it is easy to determine where the user's wifi adapter is located.
However the computed position will varies if one of the received access point varies its own power, or is shadowed by something between it's antenna and the receiver's antenna.
Note that this will be similar when the geolocation is computed using cell phone signals.
If the location is done using GPS signal with a GPS receiver embedded in the computer, then your are back to general issue of GPS position determination (number of satellites in sight, their relative position, their height on the horizon, and signal reflexion). GPS normal accuracy is "within a radius of 30 m", that is 60 meters / 200 ft.
If the location determination is done using a mix of all available techniques, then the result will varies also according to the weight assigned to each technique in the final result.
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Creating application to use car count data from traffic. How do I access the live google maps, waze or bing maps data?
The Azure Maps platform has raw traffic data you can access for analysis purposes (I have been working with several others who are doing this).
There are two approaches. The first is to use the Traffic flow segment API: https://learn.microsoft.com/en-us/rest/api/maps/traffic/gettrafficflowsegment
The second is to use the traffic flow tiles. https://learn.microsoft.com/en-us/rest/api/maps/traffic/gettrafficflowtile If you need traffic data over a large area, this is the lost cost approach, although more complex. Azure Maps provides the traffic flow tiles in both image (raster) like most platforms, but also in vector tile format (aligns with the open vector tile standard created by Mapbox). You can download all the tiles over your area of interest and extract the data for analysis. If you request traffic relative to the speed limit, each line segment in the tile will have a value between 0 and 1 which indicates the speed relative to the speed limit. For example, 0.2 would mean traffic is flowing at 20% of the speed limit.
We have a tool on our travel site which should exactly calculate the distance from the visitor location to a given hotel which is known bye longitude and latitude. To achieve this we use google API but this is not accurate, some time the visitor location is about 40/50 km from the real location. According to other coders is not possible to do better. I can't believe that there is no the possibility to detect the exact geographic location of visitor. I have seen there are some other similar question but those are 2/3 year old.
Thank you
the location of a device can be obtained in two ways, by means of GPS or by means of the approximate location of the IP. The GPS reception can be affected by various factors .. in the cities is of some importance to the Urban Canyonin ie the reflection of the GPS waves on buildings. these factors can lead to an error of several meters and particularly unfavorable circumstances even of some tens of meters .. Another mode of detection is based on the geo-referencing of the IP and on routing that uses the device through wifi networks or data connections in this case the error on the position is normally a few tens of meters ..
I'm using http://code.google.com/p/php-google-map-api/. I made an application to get latitude and longitude of different street names. But when I execute this script from outside my country this precision is lost and I can't geolocate all the streets.
I think that Google keeps a different index depending of the country you are. How can I change the country (or locale) of my API?
Once we had an experiment on Mobile Network Development. We used GoogleMaps as basic geolocation tool for mapping/locating and measuring Base Stations characteristics. As the result, we've got into trouble very quickly.
We needed rather precise data (about 5 meters maximum deviation) and what do you think ? The street which was 2 km long (what was measured after experiment with required accuracy) was calculated as 1.7 km in GoogleMaps.
Moreover, most of the patches (ground photos) that are shown on map, overlaps each other in different way. Actually, it depends on country and on the precision of shooting, because some countries are more detailed some are not (very not).
Speaking about streets, this deviation is rather considerable to say that it can be precise. GoogleMaps should not be treated as the precise geolocation tool in any case, especially if high precision is required (street level is already above-normal precision).
So, I propose you not to take into account this data very seriously. Otherwise GoogleMaps is a very nice security breach for all of us. Imagine that You have nuclear bomb or missle and you already know where to direct it with accuracy of several meters, sitting somewhere in the middle of the Sahara. Here you are ...
I have been reading the W3C Geolocation API specification and I was wondering if anyone has found any information on how accurate the location returned is.
I found the accuracy attribute:
The accuracy attribute denotes the accuracy level of the latitude and
longitude coordinates. It is specified in meters and must be supported
by all implementations. The value of the accuracy attribute must be a
non-negative real number.
But I'm wondering if anyone is aware of a possible range for these values? Is there a maximum number of meters that will be returned?
Any application I wrote that used this would be used in a relatively small geographic area, does the accuracy depend on where that area is?
Note:
I found a similar question, but it does not talk about the accuracy range and I believe they are talking about using Google's GeoLocation service.
Based on experience the accuracy on device without GPS, like laptop that only relies on Wifi mapping, is 100-200 meters in urbanized area. With GPS, like in mobile phone browser its as goods as it gets, 10-30 meters.
I use HTML5's geolocation API and the position object has a "accuracy" property which is a number that may vary depending on the accuracy of the positioning.
So far so good. But the value is an unspecified unit.. sometimes it's 60, or 1250 or even 18 000.
I've read the W3C Geolocation API Specification[1], they talk about this property but never mention how it should be interpreted.
The only place I've found a possible answer is in the Department of Defence World Geodic System[2] technical report.. They mention accuracy in cm units with a 1σ (standard deviation).
But that doesn't tell me what's the accuracy unit that the HTML5 geolocation API returns me.. I can only suppose it's in cm..
[1] http://dev.w3.org/geo/api/spec-source.html
[2] http://earth-info.nga.mil/GandG/publications/tr8350.2/wgs84fin.pdf
From the documentation:
The accuracy attribute denotes the accuracy level of the latitude and longitude coordinates. It is specified in meters and must be supported by all implementations. The value of the accuracy attribute must be a non-negative real number.
So its measurement is meters.