Robust And Compact Hybrid Environmental Lidar
(RACHEL)
Pollution Monitoring Raman Lidar
- Operates in the UV at 355 nm
- Measures aerosols, CO2, H2O, N2 and other species (see table)
- The instrument can be configured to measure several species simultaneously. Nitrogen must always be included as this is used to calibrate the instrument performance for all other measured species
- Range 10 km, 7.5m resolution
- 20 Hz, 1-10 minute averages
- Can create 2D and 3D map
- Particle measurement is most sensitive to the size range 0.1 to 1.0μm.
- Initial development sponsored by NERC
Specifications:
Gas Detection:
Minimum Detectable Concentration/ ppm/10 minute averages
| Day | Night | Night |
| Species | <700m | < 200m | 1500m |
| CO2 | 1700 | 2 | 310 |
| CH4 | 375 | 1 | 60 |
| SO2 | 500 | 1 | 100 |
| NO | 6380 | 5 | 1100 |
| NO2 | 130 | 1 | 25 |
| CO | 2800 | 3 | 470 |
| H2O | 1100 | 1 | 160 |
| N2 | 2700 | 2 | 450 |
Particulate Detection:
| Minimum Detectable Concentration/ μg/m3/1 second averages
|
| Range/ m | Day | Night |
| 500 | 0.5 | 0.5 |
| 1000 | 1 | 1 |
| 1500 | 2 | 2 |
| 2000 | 3.5 | 3 |
| 3000 | 11 | 9 |
| 5000 | 205 | 65 |
Operating Conditions:
| Temperature | -5°C to 35°C |
| Humidity | Not critical, however performance during precipitation may be reduced |
| Maintenance | Unattended operation. Laser (flashlamp) replacement typically 3 month period (depending on duty cycle selected). Routine maintenance on mechanics recommended annually |
Download a PDF version of this page.
