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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My Galaxy Note 4 (already updated to latest Android) tends to lose
connectivity to GPS (even though the connection to cellular/mobile
data network seems to be intact) while driving for 3 to 30 secs.

I'm using Waze.  The disconnection can happen even on a bright
sunny day (ie don't have to be cloudy/rainy days) or in open
highway (ie not while going through tunnels).

The same SIM card was previously used on my Galaxy Note 2 for
for almost a whole year previously & I never had this issue.

Is this a known issue with Note 4 or the Telco ?  Maybe one way I
can test this is to use the Note 4 as a hotspot (tethering) to an
iPhone & test to see if Waze/GPS  disconnects intermittently:
map is still there but there's a red alert message that 'connection
to GPS is disconnected' at the top of the screen.

I only noted 2 changes:
1. I switch from Note 2 to Note 4 at around the time I disposed
    the old Honda Airwave to Toyota Sienta hybrid: not sure if
    there's something in Sienta that interferes
2. Note4 tends to get very heated up while Note2 is not that
    hot while Waze is in use: I've since taken out the backcover
    of the Note4 (& used scotch tapes to hold the battery & SIM
    card in place) when in use so that the heat dissipates
Become a Microsoft Certified Solutions Expert
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Become a Microsoft Certified Solutions Expert

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Can I replicate a search using the Google Maps API local search with  an iOS MKLocalSearchRequest() ?  For example, using the Google API, making a map search using the keyword "hostels" works correctly. In iOS using MKLocalSearchRequest(), using a naturalLanguageQuery, I just get hotels. Is there a way to fix this?  Or am i forced to use the Google Maps API within iOS?
Need SLQ (or other systematic way) to change XCOORD and YCOORD  into the  Latitude and Longitude GIS format.

Sample XCOORD: 2121551
Sample YCOORD: 19744813

Sample Latitude: 29.49252
Sample Longitude: -98.67554

I have  a data set of 500 000 rows and need to have a daily systematic way to have this done in SQL (preferably).
I have the following c# code(all variables are doubles)

 if (Latitude == lastLocation.Latitude && Longitude == lastLocation.Longitude)

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This just compares exact numbers, what i need to do is Compare latitude and longitude to see if in 10 meters of previous location
This code runs 100 times a second, so i need it to be super fast too

I'm not sure how to achieve this so would appreciate some code help
Where can I buy gps tracking device who will upload location to server at your own choose.
Hiding labels on Google Maps / Street View

There is a label in exactly the wrong place and I need to hide it.


Plotting Photos on a Map

I have pictures from an iPhone6, iPhone 7 and a Canon PowerShot.

I know the iPhone 7 photos have the geo coding embedded. But I need to verify the Canon Power Shot is working for geo coding.

And if not, I may buy a new camera for myself.

And how do I view a folder of image and plot them all on a map?

Need Free Satellite Photos of New York City

I found Google Earth displays perfectly the images I need to use. But if I used that image in a presentation, I could be sued by Google.

So, I would never do that, clearly.

Are there other ways to get Satellite Photos of New York City which are public domain? Or that have some easy to accept license such as putting a copyright notice at the bottom?

I heard some French company had some which were free?

Can you please give me any Satellite Photos websites I can check their terms??

Hi I need to find the distance between 2 pin codes. For that i would like to find the center point within each pincode and calculate distance between them. This is for my internship project. So how to find the center point within each pin code?
Employee Tracking - GPS - I want app to web solution for tracking my sales employee and location with form to be filed when they reach that location.
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There a lots of gps apps, but usually they are more for cars & vehicles.  We are looking for one that can we can find each other within a mall or a department store.  Any EE knows of any good ones?

I need to calculate the Grid value based on lon/lat value of particular point  on map. The attached file display the "test_incident" point , need to calculate that point grid value.

Is there any formulas /algorithms  or any API to calculate the grid value.

I wanna buy a tablets for sales staff at the company to use Citrix Apps and also to track their track.

1- What are the best brands with best price.
2- These tablets must be easy to monitoring by auditing account staff.
3- Is there a mobile printer that can be connected to the tablets and what are the best types?

I have to process a list of latitude and longitude co-ordinates to see if a device has moved in/out of a geo zone

Previously, the app was single threaded, and we delayed processing this information for a few minutes, then we ordered the list by the dateTime and then checked each item in date order to see if it entered / exited a zone

12:00:01 - not in zone
12:00:02 - not in zone
12:00:03 -  in zone
12:00:04 -  in zone
12:00:05 -  in zone
12:00:06 -  in zone
12:00:07 -  in zone
12:00:08 - not in zone
12:00:09 - not in zone

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this then saves date to db like
12:00:03 - entered the zone
12:00:08 - exited the zone

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We have since made the console app multithreaded and we are now seeing race conditions where the data is processed in the wrong order, and its causing data integrity issues where sometimes exits the zone too early, and then the next record see's its inside the zone, therefore its creating data like this

12:00:06 - entered the zone
12:00:08 - exited the zone

12:00:04 - entered the zone
12:00:09 - exited the zone

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the user then thinks the device entered the zone twice, when it was infact just once

Due to the high volume of data we process we need to stick with multithreaded solution
We currently check the next item in the list against the in memory "lastPosition" object

I'm now thinking we need to change the approach where we check 1 record against another, and batch the records to speed up performance …
What are the Least expensive tracking products and options for tracking my vehicle using GPS?

  I am running a loan business for cars.

  I am looking for a GPS software solution that would allow me to monitor each car.   With features that allow me to track the car locations, turn it off, and help me in case to locate the car if the customer does not pay.     Could be web base, monthly payments, safe and secure installations of the device in the car and others features.

  Please send me your recommendations.


   Joe Echavarria
If I do geolocation on the IP of a Squarespace site I get the location of the Squarespace server, which doesn't tell me anything about where the business is located.  So how can I find all the Squarespace websites  for businesses located in a certain area, maybe a zipcode or a county?

Thanks for any ideas.
I have a simple equation to calculate the "CL" from the sum of four different grids as:

CL = A + B + C + D

I am attempting to use the mc2d package with R to express uncertainty in the CL results based on uncertainties in each of the input grids.

The uncertainty in each input grid is expressed based on uniform distributions with uncertainty ranges of:

+/- 6 for raster A
+/- 10 for raster B
+/- 12 for raster C
+/- 5 for raster D

I would like to run a Monte Carlo simulation whereby the input grids are summed multiple times (e.g. n = 1000) based on values for each grid cell that are randomly selected from within these uncertainty ranges

The code below fails with:
Error in .calcTest(x[1:5], fun, na.rm, forcefun, forceapply) :
    cannot use this function

Any suggested edits?

library(mc2d) #load package

# Input grid files
A <- raster(matrix(c(20, 35, 40, 60), nrow=2))
B <- raster(matrix(c(6, 10, 13, 14), nrow=2))
C <- raster(matrix(c(6, 8, 12, 14), nrow=2))
D <- raster(matrix(c(35, 40, 50, 60), nrow=2))

# combine the RasterLayer objects into a RasterStack 
s <- stack(A, B, C, D)

# Uncertainty distance for each raster used to establish the 
# min/max for the uniform distributions in the function just below
uA <- 6
uB <- 10
uC <- 12
uD <- 5

# Function for generating CL
fun <- function(x) {
  # Convert each raster to mcnode object
  dA <- mcdata(x[1], type="0")
  dB <- mcdata(x[2], 

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The  following  code  is  for  gps  gsm  module.The  compiled  hex  code  is  pushed  to  microprocessor.
While  compiling the  below code  we  get  unknown  variable  error  for  following  variables UCZS0, UCZS1
Please  guide  us  for  same.

//GPS and GSM Based Vehicle tracking system
#define F_CPU 12000000			//12Mhz
#include <avr/io.h>			//Header file for AVR device specific I/O Definitions.
#include <avr/pgmspace.h>		//Header file for incorporating program space string utilities.
#include <util/delay.h>			//Header file for incorporating delay routines.

#define USART_BAUDRATE 9600
#define BAUD_PRESCALE (((F_CPU / (USART_BAUDRATE * 16UL))) - 1)

void WaitMs(unsigned int ms);		

void usart_init();
unsigned int usart_getch();
void usart_writech(unsigned char data);
void usart_message(unsigned char *var);

unsigned char value,i,lati_value[9],lati_dir, longi_value[10], longi_dir, final_message[30];
unsigned char deg = 0xB0;

int main()



	for(i=0; i<9; i++)

	lati_value[i] = usart_getch();

	value = usart_getch();

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I got API key from google map. But it does not work and I use localhost. Not sure it is because localhost issue and please some help to test ...
How can I have Google maps show markers for an input list of mailing addresses
I have a google visitor map that uses Geo location that has stopped working on the live site but still works @ locallhost

I'm thinking it could be because I don't have  SSL certificate!

Looking at the webhosting website they charge from £25.99 per year which seems a bit steep considering I only want it so the google works

My question is do I need a  SSL certificate?
If so do I have to go through the hosting company or can I register for free?

Although I've moved forward I'm  Using the as a start point I have a couple  of further questions

1 Why isn't the icons / markers blue I've tried using relative path and absolute but the  marker stays the default red
My point is I can't change the marker.

2 how do I ensure only 1 popup box is open at once
<!doctype html>
    <title>OpenLayers Click Event Example</title>
  <script src="//"></script>    </head>
    <body onload="init()">
    <div class="wrapper">
        <div class="container">
        <h1 >OpenLayers Click Event popup</h1>
      <div class="container">

    <div id="mapdiv" style="width: 800px;height: 500px " ></div>
      <h2>Custom Data for clicked item</h2>
      <pre id="result"></pre>
    <script src=""></script>
    <script type="text/javascript">
      //Set up a click handler
      OpenLayers.Control.Click = OpenLayers.Class(OpenLayers.Control, {                
        defaultHandlerOptions: {
          'single': true,
          'double': false,
          'pixelTolerance': 0,
          'stopSingle': false,
          'stopDouble': false
        initialize: function(options) {
          this.handlerOptions = 

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I'm looking for a small GPS tracking device that can be put on devices such as laptops or keychains that can then be tracked to its exact location using a GPS tracking system.

I've already looked at systems such as the Trackr device ( but this device relies on the Trackr tracking device coming into 100 feet of an iPhone or Android phone that hasthe Trackr app installed on it.

What are some other GPS tracking devices that can truly track the GPS tracking device no matter where it goes?

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