# Questions tagged [position]

The latitude, longitude, and altitude (x,y,z coordinates) of a point, often accompanied by an estimate of error.

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### Calculating satellite position in lat, lon given the position of receiver, altitude of satellite, azimuth and elevation angles

I want to calculate position of a satellite, given the position of the receiver, azimuth,elevation angles and height above ellipsoid for the satellite. I think this should be a simple geometry problem ...
25 views

### How to get a 1m precision coordinates?

I'm working on a project which examines different approaches for indoor positioning. All of these approaches return coordinates (lat/lon). What I need to do is create a digital map to compare returned ...
50 views

### Seeking Public API to get GPS satellite's position?

Is there any public availible API that allows you to retrieve the current coordinates of satellites such as GPS and Galileo? I've only found ways to get Satellites Ephemeries and calculate the ...
33 views

### How to calculate a position based on nearby sensors with weights

I'm working on an indoor-positioning project where the users are carrying phones which can detect beacons located throughout the facility. The phone app only knows the IDs of the beacons, and can ...
91 views

### OpenLayers 4 change position on load and input change

I have map which should show position depends on input, which I control with switch. Long and Lat I am getting from API (depends on my input) which return to me coordinates. How can I show position ...
63 views

### Spatial-analyst, detecting bad ones from good positions GPS coordinates with QGIS?

I'm curious if someone else has been thru this problem and how it was solved. Many years back people marked the position manually on a map to get waypoints of for example electric wire connection ...
34 views

### How to find for which segment belongs this point?

I'm using an OSM dataset of Chicago which contains longitude and latitude of the source and the target of each segment road. I want to find the point with coordinates equals to: POINT (-87.7439318058 ...
478 views

### openlayers 3 and geolocation without HTTPS

I am creating an application where user can locate himself on map. the code is working fine in local development environment, but when i deploy it over server(IIS) the code won't work. here is code : ...
48 views

### Can not solve Kramberg equation

The problem is posed as follows: "There are 5 satellites, need to find the points: x,y,z." There is an equation: 23 ^ 2 = (x-12) ^ 2 + (y-25) ^ 2 + (z-24) ^ 2 25 ^ 2 = (x-(-53)) ^ 2 + (y-19) ^ 2 + ...
54 views

### Projection or XYs in QGIS

I am trying to project some data that I got. I have .txt files with XYs and they are correct, the problem that when I project the data, the points appearing in a different geographical location than ...
66 views

### Urban positional accuracy of Google Streetview [closed]

How does Google Streetview have accurate locations in urban environments, such as in tunnels, below buildings and next to buildings?
115 views

### Position of vehicles relative to lead vehicle

I have a set of vehicles (think railway) that are in a (semi)fixed formation. I know the lead vehicle and I know the GPS coordinates of the lead vehicle at any given time. Sometimes, I can rely on the ...
629 views

### leaflet: current location in geojson polygons

I'm coding an app with Phonegap, which requests user's current position. As an overlay I have loaded a geojson layer. I want the app to automatically extract a value of said layer at the exact ...
20 views

### Layers move when using specific CRS

Using Google Satellite for a basemap and polygons (KML) drawn from Google Earth to create additional polygons using landscape features present on Google Earth and Google Basemap, within the original ...
22 views

### Does related localization give more accuracy?

Let's suppose that we use another device as an RTK base. Both base and rover are moving and communicate constantly (via 5G for instance). Besides they get common GPS error from the satellite on the ...
118 views

### Correcting commercial grade GPS data to 2 meter accuracy in RT?

I have a set of rovers with commercial grade GPS boards (Adafruit Ultimate GPS Breakout). They send their uncorrected data to the central server. There, before recording each position in the database, ...
519 views

### How is user range error (URE) calculated/estimated in a basic receiver?

For a basic receiver how can we estimate/calculate URE when the pseudorange observable is used? Assume that it is a single frequency (L1) receiver. Is there any metric that can be used to estimate ...
475 views

### Sticking GPS waypoints to closest road?

I am new with QGIS. I want to study the performance of different GPS receivers, and to do so I need to compute the error made by each one. The problem is that I don't have any reference to be ...
169 views

### QGIS 2.14.3. positioning gap between OpenLayers layer and aerial image

When I add aerial images from a recent survey (delivered in EPSG:31468, DHDN_3_Degree_Gauss_Zone_4) to an empty project together with an OpenLayers OSM layer I'm facing a strange positioning issue. I ...
662 views

### QGIS problem with positions of imported waypoints

I'm a newbie to QGIS. The waypoint data was collected on a Garmin etrex legend H, with the grid set to OSGB36. Using Garmin's Basecamp software, I saved the waypoints as a gpx file (also xml etc ...
695 views

### Topographic Position Index unexpected result in QGIS

I am using Windows 7 enterprise and QGIS version 2.12.2 Lyon. Have found an unexpected result when I use QGIS to generate a topographic position index (TPI) raster from a 30m by 30m DEM. I find a ...
342 views

### Keep only the last marker when geolocating

I'm working with OpenLayers 2 and I managed to create a javascript to locate the users and it works fine. I added a marker representing the current location and when the position change, it creates a ...
861 views

### Find out if overlaying polyline matches polygon centerline in qgis

I have a polygon and a polyline and I need to find a scientific way of how close that polyline is to the actual polygon centerline. Is there any way of doing this in qgis? Any extensions, models, ...
5k views

### Leaflet fitBounds Starting Position

I am creating a Leaflet application that uses the code from the Simple CSV template to set the bounds of the map to the selected markers. The issue I have is that I want to set a start position that ...
530 views

### Displaying current position using QGIS?

How can I display my current position in the QGIS canvas, similar to the "blue point" in google mapsa? I need this to navigate to defined points and I do not want to change the program all the time.
397 views

### Converting a geocentric latitude to a geodetic latitude [duplicate]

I'm working with a 3D model of the earth (WGS84). The input to my problem is a geocentric lat-long. Is there an efficient way to convert this to a geodetic lat-long? My initial attempt to solve ...
70 views

### Right coordinates for data defined position of diagrams

I'm using QGIS 2.8.2 and want to define the position of diagrams with x and y coordinates. The same thing works with the labels, but when I define coordinates for the diagrams they just disappear. ...
293 views

### Placing a label based on a point's location within a polygon

I have a polygon dataset and a point data set with occupants. I need to label the occupants of the house within the polygon and need the label to show up on the side associated with its polygon. ...
2k views

### Centering custom control horizontally in OpenLayers 3? [closed]

This is more like a CSS question than a GIS one. But I don't have any clue how to center an element that has an absolute position. Here's some relevant markup for my icon category selector that I ...
202 views

### Postgis - st_MakeLine and st_lineLocatePoint

Lets explain, I have 4 points (1,2,3,4), and I need to visit clients (A, B, C, D). So, I need to use st_makeline with (1,2,3,4,3)... Now I have to get % position from A,B,C,D; but in visit order. ...
183 views

### Calculate geographic position based on azimuth, distance and height [duplicate]

How to calculate the geographic position of an object in sky (Point B)(like an aircraft) from Home Point (Point A) based on only four variables: Lattitude and Longitude at Home Point, Azimuth at ...
451 views

### How to compute satellite coordinates (lat,long) given antenna's coordinates, angles and satellite height

Given an Earth station (antenna) coordinates (in lat,long) ant its Elevation (El) and Azimuth (Az), how to compute the satellite coordinates (lat,long), known its height? For simplification purposes, ...
925 views

### Calculating new satellite position given pseudorange measurements

I'm looking for a reference/text for an explicit formula to calculate a satellite position given pseudorange measurements from later epoch times. I've seen a lot of matlab code on the internet but I ...
1k views

### Trilateration using two or three points

We have a positioning system where we can measure our range without 0.1m from multiple beacons. The placement of the beacons is about on a 1-2km box. So we could get anywhere from 2-4 ranges from ...
95 views

### How to detect other objects are on which side of an object based on lat long

I am working on a system that detects the lat/long of vehicles. I want to track other vehicle's position: left, top-left, right, top-right, bottom-right, bottom-left etc based on lat/long. I have ...
823 views

### Python code to determine the position on a map using Geo-Tagging

What is a proper python code, which enables to scan photographs (when captured from a series of snapshots) and match it with a geo-tagged image database. Based on the extent of similarities existing ...
459 views

### Unique Natural Area Code (NAC) for a building

NAC is a geocode system for identifying an object anywhere on the Earth. I am going to assign a unique NAC address for each building in Detroit. But different NAC addressed can be assigned to each ...
52 views

### Recommended way to explicitly distinguish 2D from 3D locations

In strongly typed object-oriented programming environment, I want to make an explicit distinction between two types of Locations: One type would be 2D (along Earth surface), thus having Latitude and ...
311 views

### Bing OpenLayers shows OK in QGIS and Composer preview, but is misaligned after exporting to PDF

I have QGIS 2.2 running on a Mac with iOS Maverick. I have prepared a map with layers with different CRS, including a Bing OpenLayers as base layer. The project has the 'On the fly coordinate ...
536 views

### LLA vs ECEF--which to choose?

I will be providing points in 3D to an external source via XML. One coworker suggests Lat/Long/Alt and another suggests ECEF. We can do either without much trouble. We have an existing product that ...
1k views

### How to calculate position in a picture based on latitude/longitude

I have got a picture on which a user manually marks some points. Let's say for simplicity's sake these points always create a 4 point convex polygon. For each one of these points I know latitude and ...
198 views

### Analysis of positioning polygon on polygon using ArcGIS

This might be a really complex analysis and I'm not entirely sure how possible it is but it is worth a shot. Is it possible to do analysis of positioning between either a "polygon and polygon" or "...
3k views

### What format is this GPS tracking string?

I am receiving tracking data from a device and I am not sure what is the format/standard of this string in order to properly process the variables, this is a sample string received: #355488020131816##...
1k views

### How to calculate relative height of point on slope relative to nearest creek and ridge?

I'm attempting to calculate the relative height (values between 0 and 1 preferably) of waypoints on a slope along the path of least resistance. Ideally, points in creeks would have values of 0 and ...