This tag refers generically to *any* space-based satellite navigation system that provides location and time information.

learn more… | top users | synonyms (2)

6
votes
3answers
564 views

Using PROJ.4 library to transform from local coordinate system coordinates to global coordinate system using ground control points?

I have a point cloud whose coordinates are with respect to a local coordinate system. I also have ground control points with GPS values. Can I convert these local coordinates to a global coordinate ...
1
vote
1answer
228 views

How to use OpenLayers Geolocate with the OpenGeo Suite Client SDK?

I’d like to have GPS functionality added to my OpenGeo Suite Client SDK application. From what I understand it should be possible to use the Geolocate control from OpenLayers. Preferably there ...
1
vote
1answer
289 views

Automating the production of GPS-compatible map tiles from georeferenced raster maps

I have a set of TIFF maps that I want to load onto Garmin GPS 62s units. The maximum size for each tile on the GPS is 3Mb and less than 1 million pixels. I manually produced one tile, following this ...
1
vote
1answer
244 views

Android Tablet KML/KMZ App for polygons w/offline & GPS capabilities?

I am looking for an Android app which allows me to view and query polygons stored in KML and/or KMZ with a GPS point representing my location and offline capabilities. My KMZ files are being output ...
2
votes
1answer
21 views

What is “gps on demand time injection”

Android defineds a GPS device capability I couldn't find reference to It's defined as GPS_CAPABILITY_ON_DEMAND_TIME in gps.h The description in the comment explains: GPS on demand time injection. ...
5
votes
1answer
263 views

Finding Lost Samsung S4 with Lat/Long Coordinates

I lost my Verizon provider Samsung S4 phone while running on a narrow trail surrounded by brush. The phone no longer has power. Using Google Location History I obtained that Latitude and Longitude ...
1
vote
1answer
815 views

GPS Coordinates to WKID 102100

I'm currently creating a project for ios and I'm using the latest ArcGIS IOS api. I have a mapView that is using the spatial reference skid 102100 and i am receiving lat long coordinates from an ...
1
vote
1answer
46 views

Map-matching GPS points to the road network!

I am quite a newbie in Postgres and Postgis so please be simple and clear :) I am trying to do a simple map-matching (or path-inference if you wish) of some GPS points. I am using postgres(postgis). ...
0
votes
1answer
260 views

downloading waypoints from Garmin GPSmap 60cx to QGIS2.2. Am I missing a step?

QGIS2.2 64 on W7 64 is failing to download waypoints from Garmin GPSMap 60cx USB port. GPSBabel installed and the GPS Tools dialog is OK: GPS device: “Garmin serial”, Port: ”USB”, Feature type ...
2
votes
1answer
178 views

iPhone app to record 3D location information

Does anyone know of an app that would run on an iPhone or iTouch that would record the X,Y and Z information from an external GPS? I am using a Dual XGPS150 Bluetooth receiver. The GPS will record ...
2
votes
1answer
119 views

Computing the elevation angle of a GPS satellite with respect to the given receiver location

can anyone source an explicit formula for calculating the elevation angle for a GPS satellite as seen from a receiver. I can't seem to find one. Even a text reference would be great. I couldn't quite ...
0
votes
0answers
35 views

How many calculations are needed?

I am working currently on a small e-learning project at the university for a professor. Now I am not an expert or anything in this field, I just learnd what I know online from the various sources and ...
0
votes
0answers
26 views

Convert WGS 84 cartesian 3D coordinates(x,y,z) to geographic coordinate (lat/long) [duplicate]

Do you know where can I find the formula and data needed to effectuate this conversion? Sorry I don't give enough information. I get the description file of a CORS ...
0
votes
0answers
13 views

How to visualize GPS dataset fro MysQL database and select dense areas

I am using Geolife dataset for simulation. I followed the pre-processing data tutorial to store all .plt files in a mysql database and export it in a .csv file. However, I want to select the ...
23
votes
4answers
30k views

What are the major differences between GPS, GLONASS and Galileo?

What are the major differences between GPS, GLONASS, COMPASS and Galileo?
0
votes
1answer
20 views

QGIS GPS not editing offline database

I have a set of layers from PostGIS that I have converted to offline. I am attempting to edit them via GPS. If the layer is point data, then I can add in that data without issue. However when I go to ...
1
vote
1answer
29 views

PostGIS and Mobile Devices Maps

I'm still learning the world of GIS reading this Introduction to PostGIS. So far I understand things but since I have an idea that I plan to later work on, I found something that I didn't quiet grasp. ...
0
votes
0answers
15 views

Free trajectory data mining tools

I am doing a mapping of systems/tools used for different trajectory data mining tasks (e.g. trajectory classification, pattern mining and outlier detection). The tools i am looking for should be ...
1
vote
1answer
27 views

Transfer from Android phone to Windows OS truncates lat long

I am clicking GPS enabled pictures of sites which are less than 500 metres apart through Android based Samsung ACE Duos phone. I later use Google Earth on my Laptop to view these geo tagged pictures. ...
1
vote
0answers
29 views

Conversion of (lat, lon, height) from GPS to another CRS

I have latitudes, longitudes and ellipsoidal heights derived from GPS readings, referenced to the ITRF08 system with vertical datum (CGVD2013) - http://webapp.geod.nrcan.gc.ca/geod/hmod/hmod.php How ...
1
vote
4answers
173 views

exporting metadata from gps camera to spreadsheet

I have a question involving exporting metadata from a GPS camera to an application such as a spreadsheet. In essence, I'm working with a significant number of images taken with a GPS digital camera. ...
21
votes
6answers
3k views

Is GPS more accurate on specific hours of the day?

I have heard that the GPS system is more accurate, and less accurate on some specific hours on the day. If this is true, how can I get the information on when GPS is more or less accurate at my ...
0
votes
1answer
127 views

Store GPS trace with timestamps, then interpolate location by time

I'd like to: Load a 1-second interval GPS trace (not GPX) into PostGIS Then query the table at sub-second accuracy (about 5Hz), and get PostGIS to interpolate the location by time. Is this ...
3
votes
1answer
166 views

Automatically panning the map in ArcGIS when using the Time slider

I have a point dataset with time-stamps at 1 minute intervals showing a driving route. I have enabled the Time properties of the layer and I am able to use the Time slider to see the points move ...
0
votes
1answer
223 views

Trimble Net R9 Base Station Receiver File Structure

We just installed our new GPS Base Station Net R9 receiver that replaced our old 5700 receiver. The old 5700 used Trimble's GPS Base software, which the new Net R9 does not. My first problem that I ...
2
votes
1answer
4k views

Looking for an android solution for offline kml/kmz file viewer with gps support

I have some KMZ files of cadastral maps. I need to fiscally go to the boundaries of my lands (parcels) and take a look at where they are with the gps and maps support. Some of these places are not ...
0
votes
0answers
12 views

Replicating CSRS PPP solution in RTKPOST, gLAB

I analyzed the GNSS position data using CSRS , RTKPOST, gLAB. From the results, I noticed that the CSRS results for NEU errors is the least, while RTKPOST and gLAB were comparatively larger. I tried ...
8
votes
1answer
243 views

What causes the GPS offset/shift in China?

I've spent close to two full days trying to understand the nature of the infamous GPS shift in China. After sifting through the noise, two recurring symptoms are that: GPS coordinates (WGS-84) plot ...
2
votes
2answers
73 views

GIS Equipment for 911 Call Center [closed]

I am the GIS administrator for a 911 call center. Currently we use ArcGIS for our mapping, and my director recently told me that I have a budget every year to purchase GIS/GPS equipment or training. I ...
0
votes
0answers
13 views

Is there a way to create a custom, navigable GPS route?

Is there some sort of way to create a custom GPS route that can say, be plugged into a maps app like Google or Apple maps? For instance let's say I created a route that is a drive along Pacific ...
0
votes
0answers
14 views

Processing obs files in glab (PPP)

I have data for a trimble receiver and would like to run PPP analysis for its positioning errors. I use glab for this purpose. For the orbit and clock source, I use the final orbit data provided by ...
1
vote
1answer
41 views

Latitude & Longitude values from Simple Voyage Data Recorder [SVDR]

I am receiving values in the form of 0113.7276,N,10339.0121,E from a Ship Data Recorder. I am not a GIS/ GPS expert and am unable to decipher what do these values mean, because they are out of range ...
1
vote
0answers
16 views

Given raw NMEA data, how do you estimate accuracy on-the-fly?

I have streaming NMEA data from a GPS device to my application. One of the sentences includes HDOP. I previously calculated the circular error probable (CEP) for this unit. How can I calculate the ...
1
vote
2answers
75 views

What does 'Course Made Good' in NMEA string mean?

I was looking at some GPS data that a client sent me. It has lines like this: $GPRMC,183123,A,1725.4170,N,07825.4779,E,37.80,297,161214,, I was looking at http://aprs.gids.nl/nmea/#rmc, which says ...
0
votes
1answer
30 views

Getting Intra-Maps roam to interface with internal GPS

I've got Intramaps Roam installed on a Panasonic Toughpad fz-g1 with integrated u-blox M8 gps. When I open up GPSviewer I can see my position, everything seems fine. When I enable GPS with ...
0
votes
0answers
9 views

Inputs for GNSS data processing : NEU error

I have some .?o and .?n files that i need to process to obtain the NEU errors. I understand that for a very accurate estimate, i need reference stations (the more, the better) to obtain baselines. ...
0
votes
0answers
10 views

Remote USb gps device location in QGIS server

I have QGIS server in linux. I have navika usb GPS device connected to a laptop.Laptop and QGIS server are interconnected via ethernet.How do i get the GPS device location in the server as the devicis ...
4
votes
0answers
92 views

What projection system is used in China which is aligned with WGS84 [closed]

I have some GPS tracks in Beijing. I want to project it and convert the lat long degree values in meters for calculation in euclidian space. I was wondering what is the most suitable coordinate and ...
0
votes
0answers
31 views

ODK Collect GPS Accuracy

Good day. Is it possible to require a minimum accuracy of the GPS widget? I know about accuracy threshold but what I need is to prevent forward swiping/finalization of the form if GPS accuracy is low. ...
1
vote
2answers
133 views

Why does my phone's GPS suffer from “urban canyon” problems in Beijing but not New York?

In a separate question on Travel.SE I asked why my phone's GPS didn't seem to work in Beijing, China. Turns out that it was simply an "urban canyon" problem, and that the GPS did in fact work when I ...
2
votes
1answer
73 views

GPS Live tracking with qgis android

I have a Tablet 10.1 notes on which I installed QGIS Android (v. 2.8) and a Garmin GPS 62 stc. So I tried to do the "live GPS tracking" by connecting through the USB cable the GPS to Tablet. Next, ...
32
votes
9answers
30k views

Why does GPS positioning require four satellites?

I have a question on the GPS positioning algorithm. In all books I've read for 3D positioning we need four satellites, and I don't understand why. We need to calculate three variables: x, y, z. We ...
6
votes
1answer
2k views

Cheapest centimeter accurate satellite positioning (GNSS/GPS)

I am looking for a cheapest possible GNSS/GPS setup with a centimeter precision without much HW hacking. I am not able to produce my PCB or do any soldering (though I would do that if there is no ...
7
votes
0answers
1k views

Calculating compass bearing between two GPS coordinates… with a twist [closed]

I'm building a virtual tour application that uses Google's streetview code to render the panoramas into a non-distorted view. Each panorama has 1 to n links where the user can select to move on. I ...
0
votes
1answer
28 views

For GPS point data using android, default camera app or other software?

I'm curious to know about your experience using the default android camera app for geotagging photos vs other apps. I am going to trial a few different of these apps over the next month or so on ...
0
votes
0answers
28 views

Why does my Android always show same lat/long for geotagged photos? Can I override this?

I am looking to collect point data with my Samsung Galaxy S3 using Android 4.1.2 However, every photo returns the exact same lat/long position Is it possible to override this and if so, how?
6
votes
2answers
4k views

How to capture accurate GPS points using mobile devices?

I'm currently working in Vietnam as a climbing guide, but am putting my GIS skills to use by doing a side project for the company involving the mapping of climbing routes. Along with another employee ...
1
vote
1answer
214 views

Using the Live tracking with internal GPS?

We have some Panasonic ToughPads (FZ-G1) with a GPS a module built in. I know where it is and can locate in it in COM 3 and it connects, registers a signal, shows satellite locations, but refuses to ...
0
votes
0answers
27 views

how do calculate nearest point in earth map with coords

I am having trouble calculating nearest point for another point with earth coordinates. I am particularly interested in calculating the intersection of linestring vector with earth coordinates. I'm ...
0
votes
0answers
17 views

Movement along a path with inaccurate location updates

Given a path and a vehicle traveling along that path. At intervals (~1 sec) the location and speed of the vehicle along that path is provided. The location of the vehicle is not accurate, a noise ...