Information for Space and Atmospheric Sciences Proposals

Arecibo Technical Information Relevant to Proposal Preparation

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The 430 MHz Incoherent Scatter Radar.

The 430 MHz Incoherent Scatter Radar (ISR) is capable of extremely sensitive diagnostics of the ionosphere. Power from the pulsed 2.5 MW (currently about 1.3 to 1.5 MW) transmitter can be split with arbitrary ratio into two beams, allowing sensing through the observing region simultaneously with sensing outside of it or near its edge (Note: Currently, due to the damage caused by Hurricane Maria, we are running only one beam). Possible geometries are set by the locations of the two feeds on opposite sides of the rotatable azimuth arm, with the minimum zenith angle differences set by the physical sizes of the feeds. Raw data can be collected with a 25 MHz wide data taking system for later analysis while a narrower bandwidth system is used to provide on line monitoring. The current coding technique allows 300 m range resolution on the enhanced plasma line while ion line and natural plasma line data are also recorded from the same radar pulses. There are some restrictions in simultaneous viewing resulting from the extremely high signal power in the enhanced plasma line. For further information you can contact Michael Sulzer (

Active optical capability.

The ‘active’ optical instruments (lidars) have the capability to monitor the upper stratosphere to lower thermosphere. We have three systems, two of which are configurable to monitor one each of the meteoric metals: Na, Fe, Ca, or Ca+. Alternatively, one of the two metal lidars can be configured as a Rayleigh lidar to measure temperature from the upper stratosphere to the mesosphere, from about 35 to 70 km. The third lidar is a Doppler-resonance lidar that measures temperatures within the metal layer by sensing the Doppler broadening in the D1 resonance line of K.

Request for optical instrument support for ISR experiments must be included in the proposal. We encourage the PIs to contact our staff for special optical configurations and further information: (Shikha Raizada (, or Jens Lautenbach (

Arecibo Observatory Remote Optical Facility (AO-ROF) and passive optics.

At Arecibo we have a variety of airglow and lidar instrumentation. Presently, airglow sensing equipment includes two Tilting-Filter Photometers, three Fabry-Perot Interferometers, and All-sky Imagers. These instruments are located about 1000 feet from the center of the incoherent scatter radar.

The AO-ROF is located on Culebra Island (18° 18′ 18″N; 65° 18′ 05″W), Puerto Rico, about 96 miles east of the Arecibo Observatory. The design of the facility enables it to host two optical instruments requiring large domes (5-ft diameter) and four optical instruments that require smaller domes (1-ft diameter). Exterior space is also available for the installation of radio receivers or other kinds of instrumentation. For further information youcan contact Pedrina Santos (