Methods and systems for open path gas detection

1. A system for detecting and quantifying a gas, the system comprising:

a first laser having a wavelength overlapping with two or more absorption features in a spectrum of the gas;

a second laser having a wavelength centered away from the two or more absorption features in the spectrum of the gas;

at least one sensor to determine a received power of the first laser;

a communications interface to transmit the received power of the first laser to a computing device; and

the computing device to execute instructions to:

determine a first difference between a transmitted power of the first laser and the received power of the first laser; and

determine an amount of the gas based on the first difference and additional data including a second difference between a transmitted power of the second laser and a received power of the second laser.

2. The system of claim 1 , wherein the additional data comprises atmospheric data.

3. The system of claim 1 , wherein the additional data comprises data from the system collected at a different time.

4. The system of claim 1 , wherein the additional data comprises measured absorption using a known reference.

5. The system of claim 1 , further comprising a third laser having a wavelength centered away from the two or more absorption features in the spectrum of the gas,

wherein the additional data further comprises a third difference between a transmitted power of the third laser and a received power of the third laser.

6. The system of claim 1 , wherein the first laser has a linewidth greater than or equal to a distance between the two or more absorption features in the spectrum of the gas.

7. The system of claim 1 , wherein the first laser has a linewidth greater than or equal to 0.2 nm.

8. The system of claim 1 , wherein the first laser is not actively wavelength stabilized.

9. A system for detecting and quantifying a gas, the system comprising:

a laser having a wavelength overlapping with two or more absorption features in an absorption spectrum of a gas;

a controller to modulate the wavelength of the laser between the two or more absorption features and an adjacent region of the absorption spectrum of the gas having lower absorption;

at least one sensor to determine a first received power of the laser when centered on the two or more absorption features and a second received power of the laser when centered on the adjacent region;

a communications interface to transmit the first received power of the laser and the second received power of the laser to a computing device; and

the computing device to execute instructions to:

determine a first difference between the first received power and a first transmitted power of the laser when centered on the two or more absorption features and a second difference between the second received power and a second transmitted power of the laser when centered on the adjacent region; and

determine an amount of the gas based on the first difference and the second difference.

10. The system of claim 9 , wherein the laser has a linewidth greater than or equal to a distance between the two or more absorption features in the spectrum of the gas.

11. The system of claim 9 , wherein the laser has a linewidth greater than or equal to 0.2 nm.

12. The system of claim 9 , wherein the laser is not actively wavelength stabilized.

13. A method for detecting and quantifying a gas, the method comprising:

directing a first laser at an area, the first laser having a wavelength overlapping with two or more absorption features in a spectrum of the gas;

directing a second laser at a second area, the second laser having a wavelength centered away from the two or more absorption features in the spectrum of the gas;

determining, using at least one sensor, a received power of the first laser;

transmitting the received power of the first laser to a computing device;

determining, using the computing device, a first difference between a transmitted power of the first laser and the received power of the first laser; and

determining, using the computing device, an amount of the gas based on the first difference and additional data including a second difference between a transmitted power of the second laser and a received power of the second laser.

14. The method of claim 13 , wherein the additional data comprises atmospheric data.

15. The method of claim 13 , wherein the additional data comprises data from the system collected at a different time.

16. The method of claim 13 , wherein the additional data comprises measured absorption using a known reference.