2017 methane emission quantification and localization controlled release test at the Merced Vernal Pools and Grassland Reserve with sUAS
Data files
Oct 29, 2025 version files 2.39 MB
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data_2017_02_14_R.csv
1.20 MB
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data_2017_02_15_R.csv
1.19 MB
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README.md
4.28 KB
Abstract
A controlled release experiment was conducted near the entrence of the Merced Vernal Pools and Grassland Reserve at the University of California, Merced campus. A point source emission was simulated at a controlled rate and subsequent flights with a small unmanned aircraft system were conducted to localize and quantify the source. This data set encapsulates these flights.
Dataset DOI: 10.5061/dryad.cnp5hqcgx
Description of the data and file structure
This data set describes the measurements taken from an open-path laser spectrometer on board a small unmanned aircraft system during a methane-controlled release test over a two-day period. The wind speed and wind direction measurements are from a RMYoung anemometer located near the emission release location.
The source location is at: 37.374429, -120.414435
There were 27 flights that took place over the two-day period that consisted of mass balance and general detection flights. The source rates varied from 0.2 to 25 SCFH. The descriptions of the flights are listed below:
| Flt # | Date | Type Description | Flow Rate | Mass Balance? |
|---|---|---|---|---|
| 1 | Feb 14 | Downwind SE of leak | 5 | Yes |
| 2 | Feb 14 | Downwind SE of leak | 25 | Yes |
| 3 | Feb 14 | Downwind SE of leak | 25 | Yes |
| 4 | Feb 14 | Downwind SE of leak | 25 | Yes |
| 5 | Feb 14 | Downwind NW of leak | 25 | Yes |
| 6 | Feb 14 | Downwind SE of leak | 25 | Yes |
| 7 | Feb 14 | Downwind SW of leak | 5 | Yes |
| 8 | Feb 14 | Downwind W of leak | 5 | Yes |
| 9 | Feb 14 | Downwind SW of leak | 5 | Yes |
| 10 | Feb 14 | Downwind NW of leak | 5 | Yes |
| 11 | Feb 14 | Downwind NW of leak | 1 | Yes |
| 12 | Feb 14 | Downwind NW of leak | 1 | Yes |
| 13 | Feb 14 | Survey near leak | 1 | No |
| 14 | Feb 15 | Flt survey near leak and cows | 5 | No |
| 15 | Feb 15 | Flt survey near leak | 5 | No |
| 16 | Feb 15 | Downwind NW of leak | 0.2 | No |
| 17 | Feb 15 | Downwind NW of leak | 0.2 | No |
| 18 | Feb 15 | Flt survey near leak | 0.2 | No |
| 19 | Feb 15 | Downwind NW & SW of leak | 5 | Yes |
| 20 | Feb 15 | Flt survey near leak | 5 | Yes |
| 21 | Feb 15 | Flt survey near leak | 5 | No |
| 22 | Feb 15 | Flt survey near leak | 1 | No |
| 23 | Feb 15 | Flt survey near leak | 7 | No |
| 24 | Feb 15 | Flt survey near leak | 0.4 | No |
| 25 | Feb 15 | Flt survey near leak | 12 | No |
| 26 | Feb 15 | Flt survey near farm house | NA | No |
| 27 | Feb 15 | Flt survey near farm house | NA | No |
Files and variables
File: data_2017_02_14_R.csv
Description:
Variables
- time: in seconds of the day
- ch4: molar ratio in ppm
- longitude: in degrees from aircraft GPS
- latitude: in degrees from aircraft GPS
- altitude: in meters from aircraft GPS
- windspeed: in meters per second from local anemometer
- winddirection: in degrees from local anemometer
- heading: in degrees from aircraft compass
File: data_2017_02_15_R.csv
Description: Same as 2/14 case. Except, note that the beginning of this file belongs with 2/14 (i.e. negative time). This is due to the measurement system recording in GMT (UTC +0), and after conversion (UTC -7) to the time column.
Variables
- time: in seconds of the day
- ch4: molar ratio in ppm
- longitude: in degrees from aircraft GPS
- latitude: in degrees from aircraft GPS
- altitude: in meters from aircraft GPS
- windspeed: in meters per second from local anemometer
- winddirection: in degrees from local anemometer
- heading: in degrees from aircraft compass
Code/software
Any software that can visualize or read CSV files can be used.