GPS is a space-based satellite navigation system that provides location and time information.

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229 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 ...
4
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209 views

GPS data based track/trip calculation algorithm available?

Currently I'm receiving position data of moving assets every 90 or 120 seconds (depending on the asset). What I'd like to achieve now is to detect standstill and movement phases (tracks/trips) on the ...
4
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516 views

Microsoft Surface vs. iPad for mapping

I was recently introduced to the Avenza PDF app for iPad and I've been using it in the company I work for to help our field crews find their way around, and record waypoints and tracks. The app takes ...
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119 views

How to determine and send alert SMS for next bus stop in a GPS tracking system?

In my gps tracking system (PHP/MySql) I have got 5 Stops for a vehicle. Whenever the bus reaches stop 1, the passengers at stop 2 should get an SMS alert. And in the same way for the sops followed ...
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60 views

what criteria should I consider in buying a pocket GPS

It's my first time making this kind of choices, and I really don't know how to go with a choice or another. I basically know that it should have good durability , a good battery life and good ...
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80 views

Ways to measure similarities/congruence of tracks (point features) in ArcGIS

I have a sets of GPS coordinates recorded while tracking different cross country runners. What I would like to do is to compare how similar the tracks of the individual runners are. Is there a test ...
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204 views

QGIS: GPS Tracking with improved Altitude

I am preparing for archeological fieldwork in Sudan. I recently came up with RTK equipment and software using RTKlib to export the real time corrected data (cm level) to QGIS via a simulated NMEA ...
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356 views

Are there any shapefile-based GPS data recorders?

I am looking for a data recorder that can be programmed to send a serial data request to a field computer and then accept and record an incoming data string and tie it to GPS location and then save ...
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60 views

How can I store height info from GPS in QGIS?

I want to use QGIS as a tool for collecting GPS-Data in the field. One use case would be simple surevy tasks where I want to store the three dimensional position of points. QGIS is working fine on the ...
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37 views

Is it possible to display labels in background files (.imp) on Trimble GPS units?

I have been trying to figure out if this is possible for a while now. I know if you load a file in as a data file, you can click on a feature and the label will pop up. However, you cannot view a data ...
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46 views

Calculating Distances between coordinates

I have perused through the other questions that are very similar to mine but am still having some trouble. I have 75 coordinates in WGS84 that I brought in from an Excel table. They are now on my ...
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30 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 ...
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106 views

best free easy GPS software? (not necessarily 'real' GIS)

Our search and rescue group is looking for some advice on what free and user-friendly (no computer savvy required) software folks could use to interact with their own GPS. Doesn't have to be a 'real' ...
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40 views

Calculate Moving Time

I am wondering how web apps like Garmin connect or Strava calculate a "moving time" from a gps track. For example I might record a GPS track on my Garmin GPS that has an elapsed time of 5:34:26 but ...
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201 views

GLONASS Satellite Position Prediction using Almanac Data

GLONASS ICD has a section named "Algorithm of calculation of satellite motion parameters using almanac". It gives the formulas in order to calculate the position and velocity of the satellite. ...
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201 views

how to make decent sense from scattered river depth measurements

I sampled river depth at scattered positions and I want to be able to make a map and GIS layers out of it. My problems are: As the river meanders the interpolation I do in scientific packages i,e. ...
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107 views

Adjusting GPS collected data to a polyline shapefile

I am collecting data from a GPS that is attached to a car. When I display this data in a map, the set of collected points are supposed to match with the street shapefile. However what I see in my map ...
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112 views

Should 2D Positions and 3D Positions be considered conceptually different entities?

Let's suppose we want to model GeographicPositions, described by coordinates or coordinate tuples inside some Coordinate Reference System. Also, these would be put inside some sequence to represent ...
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312 views

calculating bounding box from known centre coordinate and zoom

I have a map, the centre of that map (centrepoint) is = -37,175 ( gps) I know the zoom of the map = 13 I know the size = 320x320px I know there is 111111m in a degree of latitude and a varying degree ...
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89 views

How can a GPS receiver know the estimated error?

I would like to plot a circle of possible error on the map in a GPS app. From http://en.wikipedia.org/wiki/Dilution_of_precision_(GPS), we can see that GDOP is equal to "delta of output location" ...
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119 views

Interpolate current Course value of GPS using previous Course values

I have a set of GPS data with Lat, lon and Course. I need to interpolate current value of course, using previous values of Course. The formula I am using is not accurate in curves.In C language I was ...
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150 views

QGIS on android4 with bluetooth GPS

I'm trying to set up a moving map on my tablet (asus, Android 4). I've installed QGIS (latest version), which works. I've got a blue tooth external GPS, which I've paired to the tablet. However, I ...
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142 views

From gpx to line segment 1Km using ArcGIS 10

I have gpx files containg points with attribute data such as time and date. I'd like to convert them into lines, and that is not a problem, but what I want to do is create 1Km segments with time and ...
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208 views

How would I modify GPS tracker to accept two nmea inputs and gpsmarker to include a heading vector?

I use QGIS on a research vessel and wonder whether I could modify the QGIS 1.8.0 gpsinformation widget. I want to achieve two things. 1. Change the GPS marker to a boat shape which points in the ...
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160 views

How to enable OSM map in Garmin?

I've installed two OSM maps, but I cannot use them in Garmin. See the window of Utilities / Manage Map Products: The maps are not lockable, but I cannot use them in Garmin... What shall I do to be ...
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125 views

How to configure various client applications to display AVL data?

Given x number of GPS units transmitting NMEA formatted strings back to a server (xxx.xxx.xxx.xxx:xxxxx) is there a way to listen in on the traffic and parse NMEA formatted strings for display on a ...
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405 views

How to read a .GPB file in C#?

I have a .GPB file, I need to extract the common GPS data from it but I don't find a clear structure that specify the contents of that file. as a sample record from file 00000260 02 11 A9 61 E7 96 ...
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15 views

Reference and Beacon Stations in Vietnam

I'm not sure if this question can be asked in this forum, but here it goes. I am on my way to conduct some remote sensing research in Vietnam, which includes logging of coordinates. This should ...
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22 views

GPS with QGIS--what happened to the capture point?

I have been using QGIS for years but when v. 2 came out and important functionality seems to no longer work. In 1.8 the "capture point" or "capture line" buttons on the GPS panel would work. Ever ...
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43 views

Why does the postGIS file lose geometry?

I am loading shapefile data from a GPS into PostGIS via Leica ZenoOffice. This apparently imports fine with it's geometry in the attribute table. However, when I add a postGIS layer in QGIS the file ...
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104 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 ...
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42 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 ...
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30 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 ...
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54 views

I'm new to GPS, and I had a quick question about clarity.

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 ...
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22 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)?
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62 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 ...
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194 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 ...
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197 views

how to combine GPS track logs using modelbuilder?

I'm creating a model to import GPS tracks(.GPX files) into ArcMap, this is to create a network of driveable off road vehicle routes. I've manage to do some of the things I'm trying to do, but there ...
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45 views

Location Data in TAIP Format to Geoevent Processor

We are testing whether we can get the surveyed cordinates in a Trimble GPS transferred online via TAIP format ( Trimble exchange protocol) to ArcGIS Geoevent processor . For this , one main concern ...
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145 views

GPS data cleaning - Sampling of track data

I have gotten a fairly large polyline-dataset of GPS-recorded tracks. I'd like to have a sample along the tracks for different variables. The problem is that the data has overlapping tracks. This ...
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202 views

How to approximate point to segment distance on sphere?

I would like to approximate the distance of a line segment from a reference point on the map (coordinates are gives as lat/lon). In the Cartesian coordinate system I would simply find the closest ...
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69 views

looking for a GPS device which can transmit the location directly

I am looking for a GPS device or receiver that can transmit its own location to a specified configured server directly. there will be no medium like mobile phone or computer in between GPS and Server ...
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61 views

Megellan Meridian and QGIS GPS Tools help request

I am using QGIS 2.0.1 on Ubuntu 12.04. I have a Magellan Meridian GPS and I trying to use the GPS Tools plugin to download waypoints to a layer in QGIS. I have successfully used the Gebabbel ...
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110 views

SQL procedure(s) to convert GPS traces to an ordered set of junctions in a network

I have three datasets that I have loaded into a geodatabase (spatialite or PostGIS): A set of GPS points collected from individual trips through urban areas. Points have a unique point id, a group ...
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83 views

How to calculate a missing (one or more) lat/long value of a bounding rectangle?

Is it possible to calculate an unknown (one ore more) latitude/longitude value of a bounding rectangle. The log file that I need to process provides a pair of lat/long values for Upper left and Bottom ...
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47 views

Applying SBAS corrections properly

The SBAS standard, RTCA-MOPS, contains lots of unclear information. I am trying to implement SBAS corrections by the help of EGNOS SDK which is an open source software by ESA. When I apply long ...
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67 views

What is the relationship between Map Service Instances and SDE connections?

We have a GPS project based on ArcGIS Mobile 10.0. There are two web map services and each were kept as Nonpooled with Minimum instances 15 and maximum instances 60 by original developer. The database ...
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386 views

Calculating Accurate % Grade from GPS Coordinates

I am trying to calculate % Grade from GPS points. I am using the basic equation of (Rise/Run)×100 The problem is I am getting spikes in my GPS data (example 1 meter rise for 3 meter run), I am ...
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30 views

How to tell if a device supports Assisted GPS, and if how to get the Assisted GPS cooridinates?

1) Is Assisted GPS implemented at the hardware and OS level, or is it a hardware and secondary software thing. I've never used this so wondering what is required to 'access' this. I noticed a wiki ...
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91 views

QGIS GPS bluetooth connection

I have setup a Haicom bluetooth gps on a machine running Windows8 and have used GPSGate to create some virtual COM ports. I have valid data arriving at the COM port, but then I run QGIS and try to ...