CEDAR email: Arecibo Observatory - HF Facility. Call for Ionospheric Modification proposals 2018

[Astrid Maute]

Dear Colleague:

The Arecibo Observatory invites you to submit proposals for the use of the
HF facility during 2018.  HF experiments at Arecibo are scheduled by demand
in periods of 5-7 days around new moon.  Proposals should specify the
associated diagnostics required: the incoherent scatter radar (ISR), active
and passive optical instruments and others. Proposals should be submitted
via online at http://www.AreciboObservatory.org/hf-call
<http://www.areciboobservatory.org/hf-call>.  Information about observing
proposals and policies can be found at
*http://www.AreciboObservatory.org/hf-policies.pdf
<http://www.areciboobservatory.org/hf-policies.pdf%20%0d>*

Technical information about our facilities and instrumentation as well as
the contacts for specific support are found below. For any further
information not addressed in this communication, contact Eliana Nossa (
enossa at naic.edu)

Best regards,

Eliana Nossa

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1.          Technical information.

1.1.     HF facility.

The HF facility at Arecibo transmits a maximum of 600KW at 5.1MHz, with 22
dB of gain and 13 deg. of half power beam width, or 8.175MHz with almost
26dB and 8.5 deg.  The HF transmission has a Cassegrain design where the
primary is the 300 m Arecibo dish, the secondary is a sub-reflector mesh
that reflects frequencies lower than 20MHz, and the feed system is composed
of an array of three concentric cross dipole antennas at each frequency.
The transmitters are connected to the antenna arrays by coaxial lines.
Manual control of the power gain allows ramping up and down the individual
antenna power in dB steps. Configurations using CW and pulses as short as
few seconds are mostly used.  The system supports linear, O and X modes.

For further information, contact Eliana Nossa (enossa at naic.edu).

1.2. 430 MHz Incoherent Scatter Radar.

The 430 MHz Incoherent Scatter Radar (ISR) is capable of extremely
sensitive diagnostics for HF experiments. It can run in parallel with the
HF system, being one of the essential tools for diagnostics of the
ionosphere modification over Arecibo. 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 online 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.
For further information, contact Michael Sulzer (msulzer at naic.edu).

1.3. Active optical capability.

The "active" optical instruments (lidars) have the capability to monitor
the upper stratosphere to lower thermosphere. The lidar beams are
collocated with the ISR volume. We have three systems, two of which are
configurable to observe 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 active optical instrument support for HF experiments must be
included in the proposal. We encourage the PIs to contact our staff for
particular optical configurations and further information. For lidar
observations, contact Shikha Raizada (shikha at naic.edu), Jens
Lautenbach (*jlautenbach at naic.edu
<jlautenbach at naic.edu>*), or Jonathan Friedman (jonathan at naic.edu).

1.4. Passive optical instrumentation and Arecibo Observatory Remote Optical
Facility (AO-ROF).

At Arecibo, we have a variety of airglow instrumentation. Presently,
airglow sensing equipment includes an Ebert-Fastie Spectrometer (OH
and O2 bands);
two Tilting-Filter Photometers (630.0 nm and 555.7 nm); three Fabry-Perot
Interferometers (630.00 nm, 557.7 nm and 844.6 nm), and an All-sky Imager
system (630.0 nm and 643.4 nm filters).

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 optical
instruments at ROF can observe the same thermospheric volume over AO
sampled by the Incoherent Scatter Radar (ISR). This capability is
especially relevant during the HF campaigns. The ROF is designed 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.

Presently, ROF hosts an all sky imager system (with filters to observe
630.0nm, 643.4nm and 557.7nm airglow emissions) and a High Frequency
receiver. From September, 2017, an all sky imager system for OH bands will
be available.  Space can be provided for users to deploy instruments
temporarily during the HF campaigns.

For further information, contact Pedrina Santos (pterra at naic.edu).

2. Ionospheric Prediction.

For every campaign, the SAS department will be providing the F2 peak
parameters prediction to help the users to define the best way to conduct
their experiments. These predictions will be accessible on our website at
least a month before every campaign. The predictions will provide different
scenarios depending on the solar activity, historical ionosonde, and ISR
registers. For further information, contact Christiano Brum (cbrum at naic.edu
).

------

Eliana Nossa, Ph.D.

Research Associate

Space and Atmospheric Sciences

Arecibo Observatory


Advanced Technology & Systems Division

SRI International



HC3 BOX 53995, Arecibo PR 00612

(787) 878 2612 ext 219 <(787)%20878-2612>

eliana.nossa at sri.com

enossa at naic.edu
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