Tagged Questions

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

2k views

How is Precise Point Positioning (PPP) exactly done?

I am looking for a positioning accuracy that is higher than normal consumer-grade GNSS receiver (mostly GPS/GLONASS hybrids with +- 5m precision). I came across RTK with dual receiver setup (base ...
177 views

Calculating the fastest routes and some points on the same time

I have two drivers and each driver has a set of about 15 locations where they need to drive to on a single day. Calculating the shortest route for both drivers is not the problem (using a matrix ...
85 views

Is there a method to tell which hemisphere a point belongs to, in WGS84 geoid, where the equator is an arbitrary ellipsis?

I use the WGS84 geoid (because I'm working with a GPS chip). I define an ellipsis that splits the surface in two parts, lets name these 'A' and 'B'. This ellipsis is defined by two points 'a' and 'b'...
9k views

Low-cost centimeter-level accurate satellite positioning (GNSS/GPS) [closed]

I am looking for a low-cost (< US\$500) 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 ...
3k views

Translating hdop, pdop and vdop to metric accuracy from given NMEA strings

How can I translate dilution of precision to a metric unit? For example: say I got 1.2 in hdop from NMEA sentence of my GPS receiver, in what should I multiply to get a metric accuracy? Just like the ...
206 views

Problem measuring area with gps coordinates

I am trying to measure area from gps coordinates but fail to get the correct result (7200 square meters). I used the formula from this post but I get way too high number as result (should be in square ...
4k views

How to clean/edit GPX (tracks) files recorded from GPS device?

During a long trip, I have recorded tracks of my journey with the GPS of my smartphone. I have ended up with about 30 GPX datafiles. Now that I am back, I am trying to draw a map of this trip. I ...
148 views

How does Mobile GPS work in Windows Tablets?

Can anyone tell me how GPS chips generally works in Windows8 Tablets? As far as I can tell Tablets do not have a separate GPS chip like those in handheld GPS receivers - It seems to be combined into ...
195 views

Which tools integrate Leica zeno 5 gps handhelds into ArcGIS?

What other software can I use with my Zeno 5 gps handheld device from Leica geosystems except the one they offer that integrates with ArcGIS desktop? They suggested the 'Zeno office' and the 'Zeno ...
257 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 ...
1k views

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. ...
183 views

What gps app to use for mapping bus routes?

I'm looking for a GPS app for android to capture waypoints and lines. I'm going to map the route buses and the stop points. Which GPS app is recommended for marking “points” and marking the “lines”? I'...
344 views

Accuracy issues between data in QGIS and Google Earth

Wondering if anyone can answer this question. I have a kml in Google Earth. When I import it to QGIS, and then import the Google Earth images they are in slightly different places. I used a QGIS ...
197 views

Extract one GPS fix per day from data?

I am in the fortunate position of having 2 years worth of animal movement data. With such a large amount of data I would like to extract only one fix per day to make it easier to work with. Data = 14 ...
159 views

Are latitude and longitude observations independent of each other or correlated?

I want to develop a bivariate gaussian kernel in order to handle the random noise in my GPS tracks where each point has three parameters (lat, long and time stamp). I was wondering if latitude and ...
544 views

If the GPS navigation message takes 12 1/2 minutes to cycle, how can receivers update your position every second?

According to Wikipedia's article on GPS, Each GPS satellite continuously broadcasts a navigation message... Each complete message takes 750 seconds (12 1/2 minutes) to complete. My ...
196 views

Rotate the map to GPS heading / direction in ArcGIS using ArcObjects SDK 10 for .NET

Assuming I use ArcGIS or an ArcEngine application on a mobile PC. Is it possible to rotate the map in ArcGIS to the direction the device is travelling using a GPS receiver? If yes, how? I would like ...
526 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 ...
1k views

Difference between Positioning and Localization

I would like to know what are the differences between Positioning and Localization. In most papers they are used interchangeably. Are they the same? Does one come after another? I always thought ...
519 views

Areas where DGPS with post processing (not RTK) is still required

I am wondering in which domains or countries where Differential GPS (DGPS) with post processing (not Real Time Kinematic [RTK]) is still required? It's known that RTK has been rapidly adopted by ...
113 views

Most accurate GPS hardware for less than 1 mile radius [duplicate]

I apologize if this is a duplicate but I can't find a good answer or area to know where to find the correct answer. I am looking for the technology or hardware around wearables or similar technology ...
61 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 ...
13k 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 ...
3k views

I'm using a QGIS 2.2.0 Valmiera on a Windows 8.1 system Desktop. I'm a forester and I would like to have a cheap solution to load maps into the handheld Garmin 60, 62 or 64 series GPS. Free would be ...
179 views

Calculating countries flown over on flight path

Say I have two airports given. I can then get their coordinates. Now that I have the beginning and end coordinates I can draw flight-path from the two locations. Now my question is that given two ...
134 views

Simulating historic GPS data on map [duplicate]

I have some really basic newbie questions. I have following data with me: ESRI Shape files (.shp, .shx, .dbf, .prj, .sbn and .sbx) KML/KMZ files GPS coordinates (~400k) of some cars (~50) tracked ...
148 views

Best method to find routes from a set of points

I have lines table (postgis enabled database) representing the streets. I have collected few gps points along a route and I would like to match it with the streets in order. Scenario - I am jogging ...
79 views

Determining accuracy of coordinates from handheld GPS?

I'm working on a project for class, and I'm mapping GPS on Google Earth with a KMZ file. I used a handheld GPS 24°6.691'N + 74°27.833'W. How accurate is my coordinates? I know I'm in decimal minutes!...
230 views

Use of RRC(Range Rate Control) in Pseudo Range Correction for satellite

Can anyone tell me the use of RRC in order to calculate the value of PRC(pseudo range correction) in PPK(post processed kinematics)?
629 views

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 “...
873 views

Converting GPS Positions to Google Maps

I have a set of GPS-coordinates in a database, which I want to compare to a coordinate supplied by the html5 location API. My coordinates look like this: <WGS84Coordinates> ...
95 views

Post Processing Algorithm

I am working on project In which I am supposed to make a web app which will be asking users to upload their inputs as "Rinex file" of Rover and Base Station and It will give more precise data after ...
58 views

50m x 50m grid around the world

I'd like to subdivide the earth into a grid of approx. 50 x 50 m cells (big database, I know). To make it more complicated (and fun), I also need to be able to determine to which cell a given set of ...
156 views

Can we manually select which satellites to use in solution? [closed]

For example, I have used below satellites ID in current solution: ID Signal Strength ______________________ 1 21 22 23 19 12 36 26 20 18 3 29 32 ...
67 views

How should “consumer oriented” geographical applications be called?

I se the term GIS being used for professional applications, while there is a growing interest on applications (online or desktop) that use Web Maps and User-Generated GPS Data so that individuals can ...
487 views

Project point to map with Arcpy using GPS Coordinates

I am trying to create a new layer with just a single point using arcpy. All that is provided is a gps lat and long. It seems like it should be a simple problem but I just can't get it to work. I've ...
174 views

Looking for a good solution to have GPS position on KMZ files on Android platform

I'm looking for the best solution / app on the android platform to show my GPS position over a KMZ file, possibly offline. Here is what I've tried to do: Google Earth Android app I downloaded KMLZ ...
570 views

How to convert gps receiver native format to google lat long or XY format

I have received some GPS co-ordinates in the following format like - "17267690N 078279340E".. How to convert the co-ordinates to show it on Google map.
88 views

GPS positional, and quality data collection using QGIS

I was wondering if it was possible to record the position along with some of the quality control data in a table when using the GPS information functions to collect some mapping data. I would like to ...
6k views

How can I convert Horizontal dilution of position to a radius of 68% confidence?

I am working at mobile app that uses external GPS module. What I need is to calculate accuracy for the fix from GPGGA command to be able to compare it with my mobile platform's GPS accuracy. Mobile ...
156 views

How to know the exact country or province from the longitude and latitude information automatically?

To be more specific, how to find all of point (from 1,000,000 items) located in England, or located in California? I need to process over 1,000,000 items, so a offline and automatic way is needed. ...
65 views

Why is “Add feature” of the GPS Information tool inactive for some of my PostGIS layers?

Sorry If I rise it again on this forum but I couldn't find any info on limitations/requirements of "GPS Information" tool for QGIS (2.2.0) against data layers. For some layers I'm able to collect ...
127 views

Identify circuits/loops in GPS track data

This question will be naive and uneducated, but I gotta start my research somewhere, so I'll ask for references and pointers... Let's say you have a GPS time series with a set of lat/long coordinates ...
724 views

What will happen when Russia shuts down the GPS stations?

Russian officials are seriously talking about shutting down US GPS ground stations within their borders and Deputy Prime Minister of Russia tweeted on the subject. What will happen to the GPS? My ...
306 views

GPS and One-way Streets

I'd like to know how GPS can determine if a street is one-way. Does it detect one-way signs or parked car positions if any?
272 views

Adding tracks to gps with QGIS feature attributes as name

I am attempting to send a vector layer to a garmin gps in QGIS. I am using the GPS Tools extension and have created a new GPX layer. I can add waypoints without any issues, but when I copy features ...
371 views

I would like to locate (position) people inside buildings without forcing them to download a native app. I'm focusing on iOS and Android devices. I therefore thought about wifi triangulation (...
368 views

Add GPS tracks directly to a PostGIS table

Disclaimer: I am a total GIS newb and I have a use case I have not seen elsewhere. Background: I drive country roads looking for old building, cemeteries, school houses, etc and I record the ...