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GIS/GPS Programming

The Global Positioning System (GPS) is a space-based global navigation satellite system (GNSS) that provides reliable location and time information in all weather and at all times and anywhere on or near the Earth when and where there is an unobstructed line of sight to four or more GPS satellites. A geographic information system (GIS) or geospatial information system is any system that captures, stores, analyzes, manages, and presents data that are linked to location(s). In the simplest terms, GIS is the merging of cartography, statistical analysis, and database technology.

I need to use my Tab 4 to drive Uber, since my iPhone 6 will not load the Uber Partner app.

So, I use my Verizon Wireless MI-FI modem w/ my Tab 4.

But the GPS is terrible!

Is this due to the age of the Samsung?

It's the only tablet that fits in my pocket!

It was already old when I bought it, but I bought it for convenience.

What can I do to get the GPS to work well on my Tab 4??
Client has a small fleet of cars and has problems with them not being where they're supposed to be, when they're supposed to be.

I see a number of products on the market but am asking the EE community if they may have some experience and/or recommendations.
Hello, I have been working in this website since long. I want to include a google map that will let users see their location with the help of geolocation, and all shops which are around them. Data about these shops are stored in a database, in multiple table. Moreoever, once this first map is loaded, the user will have the option to filter his search through checkboxes which are also generated from the database....
But i can't have my markers, even tho my geolocation is working.
 Here is my code, will you tell me where i am going wrong

<!-- Main -->
		<div id="main">
			<div class="container">
				<div class="row">

					<!-- Sidebar -->
					<div id="sidebar" class="4u">
								<li><a href="C:/wamp/www/sbm/category.html">Category</a></li>
							<div class="row">
								<section class="6u">
									<ul class="default">
										<li><a href="#">Category</a></li>
										<!--generating the checkboxes-->
									include_once 'connection.php';

# execute search query
$sql = 'SELECT CategoryName FROM CATEGORY';
$result = $db-> query($sql);

#check the result
if (!$result)
    die('Could not successfully run query: ' . mysql_error());
echo "<table>";  

// run through the results from the database, generating the checkboxes  
while($row = $result->fetch_assoc())
   echo "<tr>";  

   echo "<td>";  
   echo "<ul class='checklist'>";  
   echo "<li>";  
   echo "<input 

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This problem has been going on for a little while and I'm pretty sure I'm really close to achieving what I need.

I have a GPS script using javascript that uses the function geoFindMe() to output into the id of the div "show".

However, this displayed both longitude and latitude as one.

Therefore I decided to separate them by using .values in the javascript so that in the form both values would be separated.

This worked however it takes two clicks to actually get the GPS information in the two inputs.

This will be a part of a form where on SUBMIT of that form the longitude and latitude are stored in the database without the user seeing anything so their location can be verified at a later date.

I need help creating this so that on the input submit the location longitude and latitude is stored in a MySQL database.
I have set reference and used the name space of ESRI.ArcGIS.Geoprocessor.dll. It throws "'System.Runtime.InteropServices.COMException' occurred in ESRI.ArcGIS.Geoprocessor.dll" at the below line of code:

ESRI.ArcGIS.Geoprocessor.Geoprocessor tGp = new ESRI.ArcGIS.Geoprocessor.Geoprocessor();

Please help if I need to make some setting changes.
I have just taken a trip to Italy took pictures with both my Canon SLR and multiple iPhones.
I copied all images  when I got home and wanted to make sure all TimeStamps are properly sequential.

  1. My SLR time was adjusted a few days into the trip to match the time zone I was in. So the first 100 or so pictures were timestamps with Eastern Standard Time (-6 hours from Italy). After I changed the time on the SLR all Date Taken were correct.
  2. iPhones time adjusted to the time zone when we landed do all images Date Taken were correct.

So I wanted to make sure that the first 100 or so images taken with my SLR had the correct Date Taken and not be offset by -6 hours.  So what I did was modify the Date Modified +6 hours, but this did not change the Date Taken and I know that this data is EXIF information and cannot be changed the same way I did for date modified.
What I did notice when examine this, Date Taken vs Date Modified on the iPhone EXIF were offset by 6 hours.  So Date Taken was the time in Italy, but the Date Modified is the time in NY.  This data was not manipulated in any way.

Can anyone shed some light on why the iPhone timestamps are offset like that?
When I export data from ArcMap it change all numbers to a fractional decimal of the original number. how do you keep this from happening?
hi OSX folks

i would like to know how the heck the Maps app accurately determines my current location on OSX, based on my current public IP address, or my Wi-Fi AP (how?), or something else?

on Mac Pro Mid 2012, which in my understanding has no GPS chips equipped, can only accurately determines my location over Wi-Fi. if I open Maps while on wired connection, i got below message asking me to turn on my Wi-Fi, which ultimately goes to the internet through the SAME broadband connection as my wired interface. in other words, the two interfaces share the SAME public IP address.
Screen-Shot-2016-07-10-at-10.17.49.pngso what makes the difference? why has to be Wi-Fi?

thanks heaps,

Is there any way to link Google Earth Data in AUtoCAD Civil 3D 2017 version. I used to do it in older version of Civil 3D but now I want to do it in Civil 3D 2017.

If I have a csv with 10-50 GPS coordinates, how can I display them all at once in browser in Google Maps?

Preferably using PHP/JavaScript.

Thank you.
Could anyone look at the below link and find the info on  3x3 transformation matrices and scaling, and then tell me how I go back and forth between two coordinate systems, an original coordinate system and a scaled coordinate system.  How do I use that matrix to do this?  I kind of need the answer in plain English terms, because my math skills are minimal. (not what they used to be 30 years ago.).  

This page states "Mathematically, all transformations can be represented as 3x3 transformation matrices of the following form..."

My kid sometimes 'vanish' till late into the nights & declined to pick up calls nor
answer text messages.

One thing she never parts with is her iPhone 6 : is there something I can enable on
her phone so that I could track her whereabouts without her knowing?  Ideally
no jail-breaking of the IOS

I presume "Mobile Data" is on all the time on her phone.

Someone told me to google for "Find my iPhone" : there's a free service but
I must 1st know the password to the iPhone (which I could get fr my kid)
  i would like to know how to determine the location of an object pointed at by the camera on an ios and android,
My thinking is the location of the user/camera is determined by using the location services on the mobile device, utilize the compass and camera in the phone to determine the distance to object(building) in the center of the camera view?
utililize the distance and compass/angles to determine the lat/lon of the pointed at building. Reverse geo-code the coordinate to get the actual address.
Is this feasible? are there any API's provided by Android/IOS that would facilitate this?
I hv been using Waze to navigate taxi driving the last 7 weeks or so.

For yesterday n today, it has been recommending the longer routes (longer by 33 to 65%) n sometimes leading me to incorrect points.  Passengers n I noticed it.

It is understandable if the shorter routes are jammed with traffic but this is not the case.

When I tap on the list of alternate routes, I could categorically say tt the usual routes tt are the shortest are mis-calculated to be the longest routes both in terms of time needed to traverse it as well as time taken.

Wat cud have gone wrong?
I am looking for a format that will provide me with longitude and latitude of building withing a city block/campus block.  I am hoping to overlay data on top of a map.  Does anyone know what format should I be requesting.  Any good tools like Active X component that can be used to manipulate such data (like zoom in and out, put additional layer of information visually on top of the map?
I am generating poly lines using a java array called path x.  I am pulling the data through vb script in asp.  see code below:

var Pathx = [
		<%for y=1 to n-1%>
		      {lat: <%=gf(1,y,1)%>, lng: <%=gf(1,y,2)%>},
      {lat: <%=gf(1,n,1)%>, lng: <%=gf(1,n,2)%>}

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When I do the plot  I would like to change the color of the polyline based on gf(1,n,9) (Red,Yelllow,Green......) which as the color in it.  I am new to java script so I find myself in a bit a quagmire.

The following is my call for the polyline

var FlightPath = new google.maps.Polyline({
  path: Pathx,
 strokeColor: '#FF0000',
 strokeOpacity: 0.3,
 strokeWeight: swieght,

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I am thinking some how I have to do an array in javascript to get to where I want to be.  Any ideas to get me past the block.  Thanks
I'm quite dependent on my GPS (Waze) while moving / driving so when I'm inside
a tunnel (sometimes up to 12km long), there's no GPS signal.  Any way to work
around this?
One of our users has been tasked to analyze some data using QGIS. We have an MSSQL database which contains the latitude and longitude coordinates as numeric fields. We are trying to connect to this database from QGIS and load these coordinates as a layer onto the map, but for some reason only a few columns of the table in question are displayed, and the coordinates are not among them. Can anyone here explain how we could get these coordinates in QGIS directly from the database? Thanks.
Is cloning a cell phone a real thing, or just something out of the movies?
I have a data feed of lat and long coordinates coming into a website I need to convert into a string that Google Maps can read.
Essentially I need to convert this: Lat N48 42.29, Long W122.54.40 into this Lat 48.4229, Long -122.5440
Hello guys,

I have wrote a vb.net code

Const EarthRadius As Double = 6371

    Public Shared Function FindPointAtDistanceFrom(lat1 As Decimal, lon1 As Decimal, bearing As Double, range As Double) As PointF
        Dim latA As Decimal = deg2rad(lat1)
        Dim lonA As Decimal = deg2rad(lon1)
        Dim angularDistance As Decimal = range / EarthRadius
        Dim trueCourse As Decimal = deg2rad(bearing - 270)
        Dim lat As Decimal = Math.Asin(Math.Sin(latA) * Math.Cos(angularDistance) + Math.Cos(latA) * Math.Sin(angularDistance) * Math.Cos(trueCourse))
        Dim dlon As Decimal = lonA + Math.Atan2(Math.Sin(trueCourse) * Math.Sin(angularDistance) * Math.Cos(latA), Math.Cos(angularDistance) - Math.Sin(latA) * Math.Sin(lat))
        Dim lon As Decimal = ((lonA - dlon + Math.PI) Mod (Math.PI * 3)) - Math.PI
        ' lon1 + ATAN2(COS(d/R)-SIN(lat1)*SIN(lat2), SIN(brng)*SIN(d/R)*COS(lat1)) 
        'Dim lon As Double = lonA + Math.Atan2(Math.Sin(trueCourse) * Math.Sin(angularDistance) * Math.Cos(latA), Math.Cos(angularDistance) - Math.Sin(latA) * Math.Sin(lat))

        Dim prt As PointF = New PointF(rad2deg(lat), rad2deg(dlon))
        Return prt
    End Function

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Which calculates the point on specified distance in km, however, I am getting very inaccurate result (~15-20km difference). The result for values: heading 360 (0-north), 111.2km and lon 61.0000 lat -30.0000 (61N30W) i am expecting is 62.0000 and -30.0000) as the distance between longs is around 111.2km. I guess it is some accuracy problem in vb.net math calculations. Would you give me any advice how  to make this formula working in vb.net (it was supposed to give me accurate point to meters - not kilometers).

The output result of above formula currently is: 62,15471 (Long) and -29.99496.

Thanks in advance.
I'm trying to create custom symbols for use on a map to denote locations and views of photos taken in the field.

I've got lat, long and bearing.  

What I'd like to do is have markers appear on a map showing the positions where specific photos were taken, based on the lat and long, and a triangle, or arrow showing the bearing...

I can do this manually, but I'd like to automate it.

Any suggestions??

Can any direct me to site has lots of large >10mb KML files, I am experimenting with Google Fusion Tables and I am looking for some data to play around with.

Thank you.

I've created a basic Google Map on an HTML page using Javascript to show user's current location and update it as they move.

You can see it here:  http://www.squeezeoj.com/test01.html

Problem is that the accuracy is not real good and the refresh rate is too low.  So, the map is right within about 0.25 miles - which is NOT good enough - and the refresh rate is so slow that it takes way too long to update when driving in residential neighborhoods.

Code is below.

How can I INCREASE ACCURACY and REFRESH RATE of this page?


<!doctype html>
<!-- FROM: http://stackoverflow.com/questions/16222330/geolocation-moving-only-google-maps-marker-without-reload-the-map -->
<html lang="en">

        <title>Google maps</title>
        <script src="http://code.jquery.com/jquery-1.8.2.min.js"></script>
        <script type="text/javascript" src="http://maps.google.com/maps/api/js?v=3&sensor=false&language=en"></script>
        <script type="text/javascript">

            var map,
                mapCenter = new google.maps.LatLng(40.700683, -73.925972),

            function initializeMap()
                map = new google.maps.Map(document.getElementById('map_canvas'), {
                   zoom: 13,
                   center: mapCenter,
                   mapTypeId: google.maps.MapTypeId.ROADMAP


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I have a project to put a map of a particular place and have it displayed on a canvas apprx size to 3 x 1 meters.

I could access a map via my google earth application but wanting to know if its possible to have it displayed clear on the size (3 x 1 meters) without pixelated.

Or is there a way we could achieve the same result?

I just wanna a map from google earth in a bigger size

GIS/GPS Programming

The Global Positioning System (GPS) is a space-based global navigation satellite system (GNSS) that provides reliable location and time information in all weather and at all times and anywhere on or near the Earth when and where there is an unobstructed line of sight to four or more GPS satellites. A geographic information system (GIS) or geospatial information system is any system that captures, stores, analyzes, manages, and presents data that are linked to location(s). In the simplest terms, GIS is the merging of cartography, statistical analysis, and database technology.

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GIS/GPS Programming