More than one spectral plot and/or plots with varying wavelengths and/or ranges

[jgrn307]

I'd like to be able to show plots from various sensors either side-by-side or (even better) overlaid on one another. Right now, it seems we can only do overlaid plots that have the same number of bands and/or wavelengths. Can you create a manner by which the various plots (if they are pulling from different layers) can have different assigned wavelengths, and also different y-ranges? For my class, I'm trying to compare an uncalibrated raw DN image (which might have values ranging from 0 to 32000) to a reflectance image (which ranges from 0 to 1).

Another thing I'd like to show is data from a hyperspectral instrument (with 100s of wavelengths) compared to a multispectral instrument (with < 10 bands).

Is this something you would consider adding?

[radosuav]

It sounds like a useful feature but also a lot of work ;) So it might be a (long) while before I find time to implement this. As a quick alternative, you can use the plugin to save the individual plots as CSV files and then do the comparison with Python or other external tool.

[jgrn307]

Thanks! It's really helpful to be able to do this in "real time" by clicking pixels. A quick suggested implementation: each layer in QGIS can have assigned a different set of wavelengths/times using the X-axis steps "From string", which is used to do the profiles. The y-axis could be set by allowing a per-layer gain/offset so if e.g. one image is reflectance scaled from 0 to 1, and the other image is reflectance scalled from 0 to 100, the user can set the gain/offset of layer one to be 100/0 so it multiplies the values by 100, thus scaling it properly.