I have read papers that use LIDAR-like and LIDAR-Raman systems that detect elements.
I want to measure the vapor water ($\rm H_2O$) and $\rm N_2$ of trees/agriculture using Arduino and low cost elements (DIY).
I am thinking of using 405 nm, 50 mW laser. The problem is how can I detect the returned wavelength?
What I am thinking:
- A CCD sensor?
- A Photodiode array?
- A modified webcam?
- A photodiode with a filter?
My question is what do I measure with the wavelength sensor? The time from when I send the pulse of the laser and the time it returns in the wavelength sensor? Only the wavelength? Should I send a specific coded message with the laser? For example 101010011?