How to calculate wavelength and phase speed of a wave from images?

Using no of images i have made a keogram which is attached here. in that x axis denotes time and y axis denotes distance (km). in this figure we can see a wave structure. i want to calculate the wavelength and phase speed of the observed wave using matlab. How can i do it??

Answer 1

[Dung Nguyen]

Hi you,

How do you have made a keogram?

[Sivakandan Mani]

Hi Dung,

Keogram is useful to investigate the temporal evolution of the waves observed in a spatial dataset.

If you use spatial data e.g. airglow images, select particular pixels horizontally or vertically from each image and arrange them into a single matrix. Now we know the time of each image and the spatial scale of the images using these pieces of information we can make the keograms.

we have described that in detail in the following papers:

1. http://www.researchgate.net/publication/280824555_Revisiting_the_Airglow_Image_Analysis_to_Obtain_and_Visual_Representation_of_the_Spatial_and_Temporal_Information?enrichId=rgreq-eb4fdd3d-af39-478a-adc9-d52b0ff43957&enrichSource=Y292ZXJQYWdlOzI4MDgyNDU1NTtBUzoyNjA3NTUwNjkwNzU0NjBAMTQzOTE4MDI2MTg3Ng%3D%3D&el=1_x_3
2. https://www.sciencedirect.com/science/article/pii/S1364682618306497

I hope it helps.

If you need any further information, I am happy to share it with you.

With regards,

Siva

[Dung Nguyen]

Hello you,

Thanks for your answear.

Do you have any code about keogram which write by Matlab?