[defrost]

> Also, from their methodology and instrumentation (color cameras) it seems they could have done it in like 80s. Why coming out now?

The 80s were mostly about DSLR cameras with film (whether colour or black and white).

These three are currently focused on what can be determined from CMOS cameras using more recent techniques.

eg:

Meteor colorimetry with CMOS cameras

https://arxiv.org/pdf/2106.07403.pdf

treats digital captures as a limited range spectrogram in the visible spectrum normalises values and attempts to determine estimates for "the characteristics of meteors such as temperature, chemical composition, and others".

As this approach is based upon "new algorithms for estimating temperature, heat radiation emitted by a fireball, and spectra of meteors containing emission lines using a new approach based on colourimetry" it seems they are publishing now as they had neither the cameras nor the algorithm some 40 years ago, and perhaps were not yet born.