NSF Special and Non-NSF Supported Activity

Design of the Visible Spectro-Polarimeter (ViSP)

ViSP is a spectro-polarimeter designed at HAO for NSF’s Advanced Technology Solar Telescope (ATST). ViSP will be able to observe up to three spectral lines between 380 and 1100 nm simultaneously in two orthogonal states of polarization. In FY2010 HAO was awarded $250,000 by the ATST project to develop the conceptual design of the instrument, and to provide a review-ready preliminary design for the optical, mechanical and software aspects of the project. This Preliminary Design Review (PDR) is planned to occur in January 2011. After going through a detailed trade-off study of different optical designs, the HAO team has reached the concept that is presently being finalized with the help of an external optical consultant. Several software tools were developed in-house in order to characterize the instrument performance and verify against the instrument's science requirements.

Data Service for the Solar Dynamics Observatory (SDO)
Figure 12. (top row, from left to right) Magnetic field strength, inclination, and azimuth field strength corresponding to the active region indicated by the open box in the full disk image.

Figure 12. (top row, from left to right) Magnetic field strength, inclination, and azimuth field strength corresponding to the active region indicated by the open box in the full disk image.

The Solar Dynamics Observatory (SDO) is a NASA satellite mission designed to study the causes of solar variability that impact life and humanity's technological development. Solar variability is intimately related to magnetic activity. The main goals of the SDO mission are to understand the mechanisms that produce these magnetic fields and drive them to the surface and to be able to predict when and where the energy stored in them is released in the form of particle ejections and changes in solar irradiance. SDO was launched from Cape Canaveral on February 11, 2010, carrying three instruments on board. One of these instruments, the Helioseismic and Magnetic Imager (HMI), is devoted to registering the velocity oscillations and the magnetic field on the Sun’s surface. HMI measures the intensity and polarization of photospheric Fe I 6173 Å line in order to study velocity oscillations as well as the evolution of the vector magnetic field at the solar photosphere. In support of SDO data analysis, HAO has developed a spectral line inversion code called VFISV (Very Fast Inversion of the Stokes Vector) to process the HMI data and to determine the full 3-D topology of the magnetic field and the line-of-sight velocity at the solar surface. These are some of the data products that will be made available to the scientific community through the NCAR-sponsored CSAC. Figure 12 shows an example of magnetic field measurements by the HMI instrument. Our task at HAO is to maintain this aspect of the data pipeline, to perform quality control of the raw data, and to disseminate the final products. Among other characteristics, the VFISV inversion code is capable of processing the full disk image of the Sun with 4096x4096 pixels in less than 12 minutes, enabling us to offer to the solar community continuous high-quality measurements of the vector magnetic field on the solar surface at a relatively high spatial resolution and cadence.

MLSO Infrastructure

Through NCAR, NSF funds were provided in FY2010 and FY2011 for essential infrastructure maintenance. This funding provided for road access maintenance and repair in collaboration with NOAA, ongoing building upkeep needs such as interior/exterior repair and periodic cleaning services.

MLSO Telecommunication Upgrade

NSF awarded HAO one-time funds to upgrade the existing telecommunications system that transmits observation data from MLSO to HAO and the broader community. This upgrade began in late 2010 and is scheduled for completion in mid-FY2011. The new system will increase bandwidth capacity from the current capacity of 1.3 Mbps to over 20 Mbps, and serve the increased data needs of the CoMP instrument installed earlier in FY2010. With this upgrade, images will be processed and posted on the MLSO web site within minutes of acquisition providing near real-time access to the data. Further benefits will include providing HAO scientists with the ability to assess data quality and instrument performance, correct problems in a timely manner, and provide scientists at SWPC and elsewhere in the community with data needed to create real-time forecasting of space weather conditions.

Fabry-Perot Interferometer in Antarctica

Instrument development work began on the new Fabry-Perot Interferometer (FPI) that is scheduled to be installed at Palmer, Antarctica. This effort is being conducted in collaboration with Australian scientists who have FPI instruments at Mawson and Davis Antarctica to jointly analyze the neutral wind and temperature data to address the following issues: (1) thermospheric neutral wind effect on the Weddell Sea Anomaly, (2) lower thermosphere wind effect on shuttle plume drift, (3) nonmigrating tides in the mesosphere and lower thermosphere, and (4) geomagnetic effect on the thermospheric wind. The deployment of the FPI to Antarctica will provide some answers to a long-standing question regarding the Weddell Sea Anomaly in the Antarctica Peninsula region. Deployment of the FPI will begin in early 2011.

High-altitude Interferometer WIND experiment (HIWIND)
Figure 13. HIWIND, in its full configuration, during integration testing in September 2010. The large white tubes pointed upward at an elevation angle of 50º direct light from four orthogonal directions into the FPI instrument located in the interior of the gondola in an environmentally sealed pressure vessel. Exterior equipment visible in this picture includes the rotator on the top, GPS and communication antenna booms, solar arrays, thermal radiator, ballast hoppers, and landing pads. The payload weighs close to 2250 pounds and will be lifted by a 40-million-cubic-foot balloon to the stratosphere. (Photo courtesy of Brett Vincent of NASA Wallops Island Facility.)

Figure 13. HIWIND, in its full configuration, during integration testing in September 2010.  The large white tubes pointed upward at an elevation angle of 50º direct light from four orthogonal directions into the FPI instrument located in the interior of the gondola in an environmentally sealed pressure vessel. Exterior equipment visible in this picture includes the rotator on the top, GPS and communication antenna booms, solar arrays, thermal radiator, ballast hoppers, and landing pads. The payload weighs close to 2250 pounds and will be lifted by a 40-million-cubic-foot balloon to the stratosphere. (Photo courtesy of Brett Vincent of NASA Wallops Island Facility.)

HIWIND is a NASA-funded stratospheric balloon-borne FPI. It will measure thermospheric neutral winds by monitoring Doppler shift in the O 630 nm airglow emission during daytime and night. The mission involves a science flight from Kiruna, Sweden, in the summer of 2011, and will last for about seven days during which the balloon will fly westward from Scandinavia, across the Atlantic Ocean and Greenland, and finally land in northern Canada or Alaska. The thermospheric wind data will be used in conjunction with ground-based incoherent scatter radar (ISR) ionosphere measurements to study high latitude thermosphere-ionosphere interaction. These data will also be compared with various model simulation results from NCAR and other institutions. One of the major difficulties in studying the polar ionosphere is the lack of daytime measurements of thermospheric winds. This has led to great uncertainties in estimating energy transfer inside the polar cap. Understanding the energy transfer from the ionosphere to the thermosphere has a great implication for space weather research. HIWIND will fill this critical data gap.


Flying an FPI on a balloon payload is an engineering challenge. The balloon-borne FPI will be in a harsh environment with extreme temperatures. Fortunately, HAO has the expertise in both balloon-borne systems and FPI measurements and is able to provide engineering solutions to solve these problems. The instrument development is moving forward according to the schedule. HAO’s Instrumentation Group has done an excellent job in finishing the hardware construction and software development within a very compressed timeframe of eight months. The HIWIND team went to Ft. Sumner, New Mexico, in September 2010 for an integration test with NASA balloon facility communication and flight control systems. The instrument passed many critical tests. The HIWIND team was able to communicate to the payload via the NASA system to send commands and transfer data from ground support computers. Throughout the project, Design and Fabrication Services (DFS) of the Earth Observation Laboratory (EOL) provided invaluable support by fabricating various parts for the instrument and assembling the gondola. Figure 13 shows the HIWIND instrument in its full configuration undergoing integration testing at Ft. Sumner, New Mexico.