# Tagged Questions

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

170 views

### How to get GPS coordinates of neighborhood polygon from Google Maps?

Does anyone know how I can find the GPS coordinates for neighborhoods like this: https://www.google.com/maps/place/SoHo,+New+York,+NY/@40.7236448,-74.0006793,16z/data=!3m1!4b1!4m2!3m1!...
26 views

### Time Difference of Arrival

I am trying to implement indoor positioning system in Matlab. Does any one know any simple method to find the time difference of arrival.I have 6 references and one target.Need to find the time ...
445 views

### In hyperbola model of how GPS equations are solved, why do 3 satellites give only 2 hyperboloids and 4 satellites only 3?

The Hyperbola depiction of how the GPS equations are solved: From several psuedoranges measured at the same time, we can calculate the (absolute) difference in the distances between us and these GPS ...
49 views

### GPS point elevation vs Contours layer elevation

I have some survey grade GPS points whose elevation is approx 55 feet lower than my contours layer elevations. I am using 1 ft contours and comparing point elevations with contours in the same ...
221 views

### Is there an industry-standard official mapping of Galileo satellites to global "PRN”/ID values?

In the U.S. GPS system, satellites are identified by the PRN number broadcast by each satellite. This ID is usually visible on most GPS receiver platforms that provide access to individual GPS ...
2k views

### Using Python to compute the distance between coordinates (lat/long) using haversine formula and print results within .csv

I have a .csv file with 3 columns. The first column is titled Distance and it is empty. The second and third columns are titled Longitude and Latitude which contain coordinates, for example: Distance,...
32 views

### How to find the most accurate street/road by a given coordinate and some previous locations?

I'm building an application that gets user's position and tracks its changes while driving providing some information stored in shape file. To get the most accurate information from this shape file ...
28 views

### Trouble interfacing Garmin Foretrex 101

I have trouble interfacing my Foretrex 101 GPS unit using my Lenovo laptop through the vendor's PC Interface Cable. I suspect that this has to do with the virtual COM port setting (The laptop has ...
22 views

### Metrics and features for comparison of aggregated trail dataset

I have hundreds GPS traces generated by cars for single road in the city from direction A to B. And I have hundreds of GPS traces generated by people which organized in trail in the mountain from ...
97 views

### Separating disjoint GPS path segments in Postgres

This involves a lot of code; if it's better suited for StackOverflow, please let me know! I'm working on a project involving trips that are constructed from GPS coordinates. I'm mapping the recorded ...
295 views

### Calculate road distance between GPS points

I am working on tracking system that track location of vehicles on the map and tell their total distance from the beginning till today. I have device_id, timestamp and GPS location in the table like ...
40 views

### 2 Lat/Long Segments Defined By 4 Lat/Long Points - Calculate If They Intersect & How Far Along Segment They Do

I have 2 lat/long segments defined by lat and long end points. For example, I have Segment X (defined by A.lat, A.long and B.lat, B.long where A and B are end points) and similarly Segment Y (defined ...
183 views

### Calculating radius of curvature and banking angle when set of lat, long and elevation are given?

I have set of lat,long and elevation values with me. Can you help me find the Radius of curve and banking angle. Formulae may be provided as an answer.
91 views

### Ionospheric pierce point location

I have a question regarding a parameter used in ionospheric modelling - ionospheric pierce point (IPP) and its projection on ground, subionospheric point (SIP). For ground-based GPS stations, I ...
628 views

### Using GPS tracking with QGIS and Panasonic Toughpad

I'm using QGIS with a Panasonic Toughpad FZ-M1 with inbuilt dedicated GPS. I can connect okay to the GPS using View --> Panels --> GPS information. Satellites and signal strength show up, but no GPS ...
231 views

### Reaching cm (inch) level elevation precision using drones

A road construction firm needs altitude data of road path before and after the construction and the error should be less than 3 cm (2 inch). Normally, they put a ground station and workers manually ...
195 views

### Approximating GPS coordinates for a point from n expected locations

I'm trying to find the coordinates of my point of attention (point X,marked blue). I used the GPS device of my car to collect the coordinates according to where I parked my vehicle each time I visited ...
51 views

### Garmin GLO Accuracy in Saudi Arabia

How accurate is the Garmin GLO in Saudi Arabia. I know they mention a 3m accuracy but is it achievable in Saudi Arabia. And is there a way to increase this accuracy. I require it to be around 0.5-1m. ...
31 views

### Vector file with photo direction arrow

I need to make a shp file with photo points incuding link to each points photo and at the same time should each point have an arrow pointing in the direction the photo is taken. As the photo ...
55 views

### Hand-held GPS to which I can upload imagery and shapefiles?

We've been struggling with Garmins. We can upload imagery and data using a phython script to create a KMZ file then drop it onto the GPS. It kind of works (much better on the newest units, barely on ...
124 views

### GPS parity algorithm for RTCM messages

I hope this is the right place to ask such a question. I am trying to encode some RTCM messages and they happen to be using the same parity algorithm as GPS (see section 20.3.5 in IS-GPS-200H; I've ...
89 views

### Need to include GPS data in a GIS system

I work for a small telematics company and we received a request from one of our clients about integrating their vehicle GPS locations to their ArcGIS system. Our current system simply displays this ...
37 views

### How to set datum in GPS connection setup window in ArcFM Viewer for ArcGIS Engine Application

I have a custom application based on ArcFM Viewer for ArcGIS Engine. I want to use an external GPS receiver with that application and the setup window does not let me choose a different geographic ...
138 views

### NMEA-2000 Message 129540 (“GNSS Sats in View”): SNR field is integer or decimal?

If you're familiar with the older NMEA 0183, there was a "GSV" record for reporting information about GPS satellites in view, including their SNR (signal-to-noise ratio, also known as carrier-to-noise-...
194 views

### How to anonymise a gps file?

Imagine you have a GPS trace that you want to make anonymous, in the legal sense. How would you do this? Is snapping to the nearest x distance and stripping out the time enough? Are there ...
44 views

### Implementing WaterML2 output in my web service

I'm trying to implement WaterML2 output for my sensor network webservice. Currently I report sensor data where the data includes IDs for each sensor, time of sensor readings, units and, optionally, ...
505 views

### Sub-meter Bluetooth GPS units and ESRI Collector App

We have been using Trimble XT/XH for years now, but we are at a time when we need to upgrade and do not want to drop another \$8000 for another Trimble that only causes us headaches and not very user ...
38 views

### Capturing GPS coords in EXIF header for JPEGs with ArcPad ImageBox control?

Problem with capturing GPS locations in EXIF header for JPEG photo using Esri's ArcPad and its ImageBox control. I have customized forms for ArcPad. I have added three ImageBox controls to a form ...
116 views

### Show multiple points and lines in Garmin GPS Map

I have two shapefiles that contain (1) 30 point features and (2) an extensive road network (line features) that connects them. I would like to show all data at once in the mapview of my Monterra ...
59 views

### How to choose GPS setup? [duplicate]

I need some advice on choosing a GPS setup to map estuarine habitats in the field. Our SA estuaries are often very narrow (1 to 2 km wide) and habitats are small. We distinguish between supratidal ...
472 views

### gpspipe returns correct timestamp, but wrong date (21 dec 1995)

I'm having this strange issue where my gps pipe is returning the correct location and time but the wrong date (including year). For reference, at the time of writing it is 06 aug 2015, 09:27 UTC). ...
669 views

### How to extract GPS information from Garmin Cam 20 video files

I just got a Garmin Dash Cam 20 and recorded some videos with it, and also confirmed that Garmins own player can show the GPS information on a Map. I cant seem to find any technical information on ...
141 views

### How to prepare and upload points/lines to GPS using QGIS 2.8

I would like to upload some points (e.g. locations of transmission towers) and lines (e.g. streams, roads) in .shp format to my Garmin Oregon 600, using QGIS 2.8.2. Could anyone provide with step-by-...
140 views

### How estimate or get the value of PDOP from HDOP value?

I have a gps device that are reporting me the HDOP value and the number of satellites around, but I have as requirement to get the PDOP also, the GPS device doesn't give that value. Can I get PDOP ...
27 views

### Magellan GPS stops recording data in suspend mode [closed]

Currently having a problem with my Magellan Explorist 510 GPS unit. After I start recording the track on the unit, after some time, it just stops recording data in suspend mode (which should turn ...
29 views

### How to fit gps trackings to a line with a known heading?

I have gps trackings that I know they fall into a certain pattern - a line with a known heading. How do I find the line that minimizes the distances of the points from it but is in the correct heading?...
77 views

### GPS points of a vehicle snapped to a specific polyline path [duplicate]

So I have been capturing bus GPS locations for a while now, and I am became interested in snapping them to their corresponding polyline (route). While at first this seemed like an easy enough task I ...
34 views

### match noisy GPS data to closest linestring in road network [duplicate]

I have some noisy GPS data(Points) that they are not exactly on the road because of the noise. But I want to match them to the closest road linestrings. How to do this in PostgreSQL? Data: ...
48 views

### Are there methods of filtering gps-data with metadata?

In our project we captured GPS-tracks from a few electric vehicles in the timeframe of a year. In total we captured around 13000000 GPS-points this way. The captured data comes from electric powered ...
58 views

### How to create displacement vectors in QGIS using GPS points with different dates?

Is there a way to calculate and visualize displacement vectors in QGIS ? I have DGPS points taken at the same place (ground control points), but their position moved over time as they are located on a ...
93 views

### What mathematical processes does a GPS receiver use to determine position?

I'm writing a report on the mathematics of GPS, but I'm wondering what methods the GPS actually uses. What I've done is set up the four sphere equations and solve them using the Newton-Raphson method ...
12k views

### How to locate property corners using plat map description?

I am interested in a piece of property for which I have a plat map description, giving what seem to be latitudes/longitudes of lines along the boundaries (not sure about this). The objective is to ...
153 views

### How to use NewSQL Database with GPS tool with Node.JS as server side programming

I am a web project manager and I want to create a website to show current position of cars on the map (google or ARC). I know how to create the website, but I don't know how to fetch the longitudes ...
602 views

### Do countries have a Latitude and Longitude range?

Do countries have a Latitude and Longitude range?. Is it possible to get the latitude and longitude range or boundary for each country. UK lat and long is 51.5000° N, 0.1167° W. What is the ...
75 views

### Make a line from a set of GPS points close to a specific GPS point with PostGIS

I have to develop a map-matching algorithm. At the moment I only match GPS points with the closest road segment. I'm looking for a way to compare the directions between a GPS point and a road to ...
30 views

### Calculating the distance between a set of UTM coordinates [duplicate]

I would like to calculate the distance between several GPS points, these data are projected into UTM Zone 30. I am using Postgresql 9.3 but I am happy to see results with any software or website such ...
95 views

### Trimble Pathfinder Differential Correction: ‘Uncorrected’ for block of GPS data

I’ve been collecting GPS point data without problems over the last few months. Recently, on two dates, after using Pathfinder differential correction, the exported records’ Corr_Type changed from ...
203 views

### Get vertice information and apply to line segments using ArcGIS for Desktop (or QGIS)?

I've recently started tracking bike treks using Strava and I thought it would be interesting to do some analysis on my treks. I am able to import the GPX file into ArcMap and convert it to a point ...