| Instrument: | UV Differential Absorption Lidar (DIAL) |
| Principal Investigators: | Edward V. Browell |
| Organization: | Mail Stop 401A Langley Research Center National Aeronautics and Space Administration Hampton, VA 23681-2199 |
Measurement Description: The UV Differential Absorption Lidar (DIAL) system is used to measure aerosol, cloud, and ozone profiles above the aircraft [Browell et al., 1998]. A pair of Nd:YAG and Nd:YAG-pumped dye lasers, which are then doubled, are employed to generate wavelengths near 1.064 microns, 620, 600, 310, and 300 nm. The IR and visible wavelengths are used to measure aerosols and clouds, while the UV wavelengths are used to measure ozone. The IR and visible wavelengths will be measured in both the polarized and depolarized states in order to obtain information on aerosol shapes, permitting the determination of liquid and solid aerosols. Aerosols can be measured to 30 km, while ozone can be measured to 10-15 km above the aircraft. During SOLVE, the ozone measurement range will be extended by using a photon- counting receiver. A separate telescope viewing through a window about 1 m from the first window will be added, along with a photon-counting detector and electronics. Table 1 presents a detailed list of the ozone and aerosol measurement capabilities of the UV DIAL for the SOLVE field experiment. Additional information about this system can be found in the references listed below.
| Ozone | ||
|---|---|---|
| Using analog lidar returns in normal operation mode from DC-8 window #4 | ||
| Altitude coverage | to 25 km | |
| Measurement capability | daytime and nighttime | |
| Measurement accuracy | better than 10% | |
| Vertical resolution | 750 m | |
| Horizontal resolution | 70 km (5 min) | |
| Using simultaneous photon counting returns observed through DC-8 window #3 | ||
| Altitude coverage | to 30 km (or higher with reduced resolution) | |
| Measurement capability | nighttime | |
| Measurement accuracy | better than 10% | |
| Vertical resolution | 750 m | |
| Horizontal resolution | 200 km (~15 min) | |
| Aerosols | ||
| Measurement capability | daytime and nighttime | |
| Measurement accuracy | better than 2-3% | |
| Vertical resolution | 225 m | |
| Horizontal resolution | 42 km (3 min) | |
| Depolarized measurements | ||
| Altitude coverage | to 30 km | |
| Measurement capability | daytime and nighttime | |
| Measurement accuracy | better than 2-3% relative or 0.5% absolute, | |
| Vertical resolution | 225 m | |
| Horizontal resolution | 42 km (3 min) | |
References: