Recipient Organization
SOUTHWEST SCIENCES, INC.
1570 PACHECO ST., STE E11
SANTA FE,NM 87505
Performing Department
(N/A)
Non Technical Summary
This project will develop and commercialize improved instrumentation for studies of the emission of the three most important atmospheric greenhouse gases from agricultural production activities (both crop and livestock). The data obtained by these instruments will inform atmospheric and climate models and may provide important information that can be used to optimize agricultural practices to reduce the effects of these gases on climate.The three greenhouse gases that are targeted for measurement are methane, carbon dioxide, and nitrous oxide. Agricultural production sites are known to be important sources of these gases. In particular, livestock production is an important contributor to the total methane budget, and nitrogen-based fertilizers are likely the most important source of nitrous oxide emissions to the atmosphere.This research and development project will result in a small, low-weight, and low-power laser instrument that is intended for use on small unmanned aerial vehicles, or drones, to survey and characterize the emission of these important greenhouse gases from agricultural sites in real time. The results of such measurements are expected to be useful in adapting agricultural processes for reduction in greenhouse gas emissions, for example, by optimization of fertilization strategies and schedules or in identifying situations where carbon capture may be appropriate.
Animal Health Component
70%
Research Effort Categories
Basic
10%
Applied
70%
Developmental
20%
Goals / Objectives
Southwest Sciences proposes to develop, test, and commercialize a low power compact instrument, mounted on a small drone or unmanned aerial vehicle (UAV), for the simultaneous, real time detection of the three most important greenhouse gases - carbon dioxide, methane, and nitrous oxide - emitted from agricultural production sites or any other area where monitoring of greenhouse gas emissions is needed. The compact size, low weight and low power specifications make this instrument highly portable so that it can be used not only for airborne measurements but also any environmental measurement application where available power may be limited, including land vehicle and stationary ground-based measurements. The use of a drone or small UAV as the transport vehicle for the instrument will greatly reduce the cost of making frequent measurements over agricultural sites or other measurement targets. The Phase I project objectives are:A two-laser diode laser laboratory prototype system will be constructed to measure carbon dioxide, nitrous oxide, and methane by adaptation of existing low-power and compact trace gas measurement platforms developed by Southwest Sciences.The performance of this Phase I prototype, including analysis of sensitivity and precision, will be characterized in the laboratory by calibration with reference gases, including testing in an environmental chamber and stationary outdoor testing to study thermal stability.The Phase I prototype will be mounted on a drone owned by Southwest Sciences in order to demonstrate the feasibility of UAV measurements. Successful accomplishment of these objectives will demonstrate the utility of this instrument for measurements at agricultural sites and will lead to the construction of one or more Phase II prototype instruments that can be field tested at agricultural production sites in collaboration with outside researchers.
Project Methods
The output of two diode lasers, one for measurement of methane, and the other for measurement of carbon dioxide and nitrous oxide, will be coupled into an open path multi-pass cell with a total optical path length of approximately 2 meters. The measurements of gas concentration will be made using a "direct absorption" approach as contrasted to wavelength modulation. Direct absorption is appropriate when signals are relatively large and has the advantage that calibration is very directly tied to known spectroscopic parameters. The wavelengths of the two lasers will be rapidly current-tuned across the absorption features of interest, starting the scan below laser threshold in order to record a signal zero in each scan. Proprietary compact onboard electronics will control the lasers and collect and analyze the data. A similar approach has been used in prior work at Southwest Sciences, so the methodologies in controlling the lasers and collecting and analyzing the data are well established. Ambient pressure and temperature will also be measured, and the system will be equipped with GPS capabilities in order to obtain detailed mapping of greenhouse gas emissions above agricultural production sites. If desired by users, it is also possible to add a camera to the sensor package.Although the Phase I program focuses on diode laser measurements of N2O, CO2, and CH4, the electronics in the system allow for easy integration of other peripheral sensors that could enable significant, low cost additional capabilities, such as a capacitive sensor for relative humidity. Or other non-laser sensors for CO, O3, etc. Additionally, the measurement platform could be adapted for laser measurement of other gases in other potential applications, by switching in different lasers.The anticipated efforts will include sharing the results of the work with outside researchers who study greenhouse gas emissions from agricultural sites, as well as the USDA program monitor, in order to help evaluate the success of the initial Phase I instrument development and demonstration and to develop a work plan for continuing the project into Phase II.Evaluation of the success of the Phase I project will focus especially on answering these three questions:What sensitivity and precision will theinstrument have in measuring the three target greenhouse gases over a range of environmental conditions?How will the instrument perform during UAV flight in regard to mechanical and thermal issues?Is the sensitivity achieved with this instrument appropriate for measuring greenhouse gas emissions from both crop and livestock-based agricultural production activities?