How to get the aircraft location from a flight path plot?

I have the below data (dummy data) of a aircraft flight path, with the time, latitude. longitude and heading of the aircraft in a table.

The actual data consists of more than 100k rows, and file is too big to be uploaded.

Based on the actual data, I am able to plot the flight path on a map. The flight path map has an x-axis of Longitude and y-axis of Latitude. Problem is if I want to know the location of the aircraft at a particular time (say at 7220sec), how can I get the latitude, longitude and heading of the aircraft from the plot?

Answer 1

[Chunru]

% Generate some data
t = (7020:210:10080)';
lon = 102.915 - t/10080;
lat = 1.363 - t/20000;
heading = 153 + t/50040;

% Create an interpolant
F = griddedInterpolant(t, [lon lat heading]);

t = 8024;
F(t)  % lat lon heading

ans = 1×3

102.1190 0.9618 153.1604

[Jayden Yeo]

Hi Chunru,

Thanks for your help. However I encountered an error when it runs until

F=griddedInterpolant(t,[lon lat headin]);

The error is "The grid vectors do not define a grid of points that match the given values".

[Chunru]

Can you show the size of your variables by running "whos"? If possible, show the variable "t".

[Jayden Yeo]

Hi, as below.

[Chunru]

Can you show the variable "t"? The sample points in t must be unique.

[Jayden Yeo]

The values of t are as below, The t values are unique.

7020

7230

7440

7650

7860

8070

8280

8490

8700

8910

9120

9330

9540

9750

9960

[Jayden Yeo]

If I replaced F = griddedInterpolant(t, [lon lat heading]) with either of the below,

1) F = griddedInterpolant(t, lon);

2) F = griddedInterpolant(t, lat);

3) F = griddedInterpolant(t, heading);

then it will work.

However, by using the above, it is quite tedious as I will have to run the griddedInterpolant command for each of lon, lat, heading, and then combine them into a matrix.

[Chunru]

Can you post your code and data (the data looks very small)?

[Jayden Yeo]

Thanks for your help.

I actually run your code (as pasted below) , and there's an error encountered at the line "F=griddedInterpolant(t,[lon lat headin]);", and hence can't continue.

My internet facing computer (which I am using to communicate with you) does not have matlab installed. I am running matlab in another laptop that does not have internet connection.

% Generate some data
t = (7020:210:10080)';
lon = 102.915 - t/10080;
lat = 1.363 - t/20000;
heading = 153 + t/50040;
% Create an interpolant
F = griddedInterpolant(t, [lon lat heading]);
t = 8024;
F(t)  % lat lon heading  

Below is the values of t, lon, lat, heading generated.

[Chunru]

Save the data in .txt or .mat file. Use the paper-clip (attachment) to attach the data. It difficult to use the screen-capture data.

[Jayden Yeo]

Ok, I will send by tonight. Thanks for your help.

[Jayden Yeo]

Hi,

I run the code at home using Matlab ver R2021a, and there is no error. It runs fine. In the office, my Matlab version is 2015b, and error will occur at the line "F = griddedInterpolant(t, [lon lat heading]);".

Attached is the data in .mat format. Thanks.

[Chunru]

load data
whos

  Name          Size            Bytes  Class                 Attributes

  F             1x1               976  griddedInterpolant              
  ans           1x3                24  double                          
  heading      15x1               120  double                          
  lat          15x1               120  double                          
  lon          15x1               120  double                          
  t            15x1               120  double                          

                      
%T = table(t, lat, lon, heading)
% Create an interpolant
F = griddedInterpolant(t, [lon lat heading]);
tq = 8024;
F(tq)  % lat lon heading  

ans = 1×3

102.1190 0.9618 153.1604

% If you have problem with griddedInterpolant on older version MATLAB
% you can try the following
z = interp1(t, [lon lat heading], tq)

z = 1×3

102.1190 0.9618 153.1604

[Jayden Yeo]

Thanks a lot. The command line "z = interp1(t, [lon lat heading], tq)" works.