Home PHP C# C++ Android Java Javascript Python IOS SQL HTML Categories

How do you pin point the location of a user with 3 nodes, using Triangulation?

Your approach is predicated on some flimsy assumptions.

Trilateration is determining a position in space based on three (or four, if working in three dimensions) distance measurements to known locations. Triangulation is determining a position in space based on three angular (what direction is the signal coming from) measurements to known locations. The three Raspberry PI nodes are fixed in space, and you have some measurement system where your (x,y (z)) positions for each are known.

What you have are three values of signal strength in some units of power (dBm, say) and you want that to be proxy for distance to a particular receiver. The problem is, unless you are doing this in a big empty room, it isn't a particularly good proxy. RF signals bounce off of some things, develop little interference nodes, shadows, and all sorts of fun stuff. Depending on how cluttered your environment is, this can make the accuracy of your trilateration result poor, or totally worthless.

Assuming you are operating in an empty warehouse, first you have to pick some coordinate frame and make some measurements and assign locations to your nodes. Making one node zero simplifies one of your measurements, you just need to make relative measurements to the others. Make sure your X and Y axes are perpendicular.

Then you will want to generate some data that correlates RSSI with distance. That is, walk a known distance away from the node and make a note of what the RSSI number is. If you're lucky, this measurement will be the same for each of your nodes. It might not be - not all radios are created equally. Also, not all antenna radiate power uniformly in each direction. Use that data and some handwaving to approximate distances from the known node locations; from there the rest of the implementation should be straight forward geometry (as the wiki no doubt has laid out).

Categories : Algorithm

Related to : How do you pin point the location of a user with 3 nodes, using Triangulation?
Android Location Coordinates Low Accuracy Using 3G triangulation
That depends on multiple factors, like signal strength, triangulation of 3G/4G towers... but the truth is 3G is not accurate like GPS is. but is more battery efficient. Take a look on this topic: Android:GPS coordinates are different in 3G and wifi

Categories : Java
Which is better for getting assembly location , GetAssembly().Location or GetExecutingAssembly().Location
It seems rather obvious: When you want the executing assembly, use GetExecutingAssembly. Sometimes you don't have one, for example when running as an Office add-in. You could use Assembly.GetAssembly instead.

Categories : C#
How to loop through XML nodes and child nodes using JavaScript?
Attaching the root of your loop on employee rather than name would be better for nested loops (which is what this solution will use): var employees = xmlDoc.getElementsByTagName("employee"); //outputs array of employees for (employeeIndex = 0; employeeIndex < employees.length; employeeIndex++) { var empDetails = employees[employeeIndex].children; //outputs array of details for (deta

Categories : Javascript
how to display one location from an array of location based on sensor number
I can't see your code, so it's hard to know. Here is a working solution, by calling initialize when clicking on html elements This resets the map with a new marker. Defined initialize() with parameter "select" Beneath the map variable (but inside initialize) made a marker, which picks the data using the previously defined "select" parameter. Used html element to call initialize with parameter

Categories : Javascript
Why does this point-free F# function behave differently from the non-point-free version?
getValFromMapPartial is a true syntactic function. Its signature is val getValFromMapPartial : key:string -> int. Whenever it is called, it uses the current value of someMap. That's why it works in your example; it accesses the version of someMap who has an entry. On the other hand, getValFromMapPartialAndTacit is a lambda-computing function. Its signature is val getValFromMapPartialAndTacit :

Categories : F#
Recently Add
Proving optimality for a new algorithm that finds minimum spanning tree
why this assembly piece of code do jmp forever
Find out if segment is fully inside of polygon
Algorithm for coloring a hexagon tile map with minimum distance (3) for reoccurring colors
Sort pairs to be more consecutive
To find three unique numbers whose number of occurrence is even
Dealing with duplication between unit and integration tests
reflection and symmetry in back tracking queens
Big O analysis for method with multiple parameters
Divide Huge Array of Numbers in Buckets
Algorithm to find adjacent cells in a matrix
Why this code gives WA for Petersen Graph(codechef)?
Complexity of this prime number search algorithm
How to detect if a file has changed?
Given string x,y and z. Determine if z is a shuffle
Basic decryption for simple encryption algorithm
An efficient way to assign user_ids to huge dataset under certain conditions
What's a more efficient implementation of this puzzle?
Generating prime numbers in poly-time
What if I do not use G transpose in calculating Strongly Connected Components?
Dividing an array into optimum no of equal sum sublists
Counting derangements
How to iterate through all cases when partitioning objects
Algorithm: How to find closest element, having coordinates and dimension
Developing player rankings with ELO
How to transform two set of discrete points ( vectors ) to help plotting them on a common scale
Heap Sort Space Complexity
complex root finding algorithm
Every possible combination algorithm
RSA Cryptosystem - Retrieve m
© Copyright 2017 Publishing Limited. All rights reserved.