Remote Optical Facility Updates

Space & Atmospheric Science


The Remote Optical Facility (ROF), funded through the NSF management grant of the Arecibo Observatory, is ready for new #AOScienceNow operations on the island of Culebra, located just off the coast of Puerto Rico. In addition to the existing optical All-Sky Imager that has been operating since 2016, the AO operations team is getting ready to install CARLA and PRISMA at ROF, both funded by the Puerto Rico Science, Technology, & Research Trust (PRST).

CARLA Sees First Light

The Culebra Aerosol Research Lidar (CARLA), led by Dr. Jens Lautenbach, has achieved a major milestone with its first measurement in May of 2022. This measurement demonstrates that all components such as the laser, lidar control electronics, data acquisition, and the setup of over 50 photonic and 200 optomechanical elements are working as designed.

The figure shows the atmospheric backscatter in photon counts integrated over 2 minutes. The three receiving channels of CARLA are the following: the purple profile is the reference channel, and the aqua and brown profiles are the polarization channels. With the polarization channels, it is possible to distinguish liquid particles from solid ones like ice or dust. The signal near 7 kilometer altitude indicates a mixed-phase cloud (ice and water droplets) whereas at around 10 kilometers altitude only one of the polarization channels shows a signal. This suggests it is either a liquid water or ice cloud. All three profiles show background below 13 km caused by the moon and stray light. Above 13 km altitude a chopper blocks the signal, and above 16 km the detector noise is visible.

Further testing and optimization are ongoing to increase the performance and to calibrate the polarization channels. The automatization of CARLA with rain, wind, and light sensors is also ongoing. Part of this effort is developing a camera-based airplane detection system that REU student Mitchell Larscheid is working on.

PRISMA Summer Updates:

On June 6th, Andreica Maldonado, the grant program director of the Puerto Rico Science, Technology and Research Trust, which funds PRISMA, visited the Arecibo Observatory and interviewed the Puerto Rican Initiative for Studies using Meteor Radar (PRISMA). lead investigator, Dr. Pedrina Terra.

The PRISMA is now in the Commissioning phase. The license to operate the Meteor Radar at 40.92MHz was issued on June 14, 2022 and the first tests were carried out at AO in July. The permanent radar installation at the Remote Optical Facility in Culebra is expected to occur in early August.

PRISMA lead Dr. Pedrina Terra is interviewed by the Puerto Rico Science, Technology, and Research Trust

Article written by Dr. Jens Lautenbach and Dr. Pedrina Terra

Arecibo Media Contact
Ricardo Correa
Director of Communications at the Arecibo Observatory
787-878-2612 ext. 615

Technical Contact
Dr. Jens Lautenbach
Arecibo Observatory

Technical Contact
Dr. Pedrina Santos
Arecibo Observatory

Keywords: CARLA, LIDAR, PRISMA, atmospheric, ROF