2021 Workshop:Instrumentation and Calibration
Instrumentation and Calibration for Optical Observations of the Earth's Upper Atmosphere
Location, Date/Time and Duration
Altitudes: MLT - Latitudes: global - Inst/Model: optical - Other:
Format of the Workshop
Requested Specific Days
Special technology requests
Accurate calibration, analysis, and error assessment provide the foundation for data that can be used to address a range of CEDAR strategic science topics, including coupling in the interaction region between the Earth’s atmosphere and the near space environment, lower-upper atmospheric coupling, Sun-Earth interactions, investigation of atmospheric dynamics through combination of observations such as wind measurements, and long-term climatology observations.
Accurate calibration is important for inter-comparison of observations, data/model comparisons, and long-term investigations. We invite discussion on a broad range of topics relating to passive optical and lidar observations and their analysis. Possible topics include: techniques for brightness calibrations; spatial scale determination; error analysis; correction for scattering within the lower atmosphere; spectral and velocity calibration; and spectral fitting approaches. Other topics of discussion could be: information on new detectors or other technologies that have been developed since the last workshop; or ideas for new instrumentation or techniques enabled by this new technology. In addition, we welcome modelers to discuss use of observations for model-data comparisons, and associated questions and challenges for model validation. We especially welcome and encourage presentations by students and international colleagues. Time will be set aside for a round table discussion of the idea of developing an “Optics School” along the lines of the well-established Incoherent Scatter Radar School.
Agenda: Instrumentation and Calibration for Optical Observations of the Earth's Upper Atmosphere
Conveners: Jeff Baumgardner, Susan Nossal
Day: Friday, June 25 2021 Time: 10:00AM – 12 Noon (MDT) GMT-6
10:00-10:05 Welcome, Jeff Baumgardner , Center for Space Physics, Boston Univ.
10:05-10:20 Calibration and preliminary analysis of Ebert-Fastie spectrometer data recorded from the Arecibo Observatory, Sukanta Sau (AO), Fabio A. Vargas(U of IL), Pedrina Terra (AO), Christiano G. M. Brum(AO), and Robert Kerr(CPI)
10:20-10:35 Neutral Wind Measurements in the Lower Thermosphere - ICON/MIGHTI and TIMED/TIDI Cross-validation, Manbharat Dhadly(NRL)
10:35-10:50 TBD, Don Hampton (U of AK)
10:50-11:05 Application of the imaging FPI to 630 nm dayglow observations, John Meriwether(NJIT)
11:05-11:20 Considerations for analysis and error assessment in multi-decadal data sets, Susan Nossal (U of WI)
11:20-11:30 Long term calibration of an All-Sky Imager using stars, Jeff Baumgardner(Boston Univ.)
11:30-12:00 Round table discussion on the possibility of creating an “Optics School” similar to the “ISR School” currently funded by the NSF, Everyone!
Title: Calibration and preliminary analysis of Ebert-Fastie spectrometer data recorded from the Arecibo Observatory
Authors: Sukanta Sau1, Fabio A. Vargas2, Pedrina Terra1, Christiano G. M. Brum1 and Robert Kerr 1) Arecibo Observatory, University of Central Florida, PR, USA 2) University of Illinois at Urbana-Champaign, Urbana, IL, USA. 3) Computational Physics Inc. (CPI), North Chelmsford, MA, USA
Abstract: A one meter Ebert-Fastie Spectrometer (EFS) was routinely operated in the Arecibo Observatory for several decades starting from the 1970s. The EFS was used to estimate different airglow emissions including the OH Meinel band lines. In this presentation, we shall discuss how to utilize the different calibration procedures to extract useful spectral information. Then, we shall describe the method used to estimate rotational temperatures in the Mesosphere and Lower Thermosphere region with the help of the EFS airglow intensities. This will be followed by examples of temporal variations of the airglow intensities and the preliminary derived rotational temperatures.
Title: Neutral Wind Measurements in the Lower Thermosphere - ICON/MIGHTI and TIMED/TIDI Cross-validation
Author: Manbharat Dhadley, Naval Research Laboratory
Abstract : This study cross-compare ICON/MIGHTI and TIMED/TIDI lower thermospheric neutral wind measurements from low southern hemisphere to middle northern hemisphere latitudes. Because TIDI is in high and MIGHTI is in a low inclination orbit, frequent conjunctions spread over wide geographic regions are occurring between them. It provides us an unprecedented opportunity to perform a large-scale cross-calibration study of MLT neutral winds from two independent space-based optical sensors. TIDI and MIGHTI local solar time (LST) coverage does not vary much each day and conjunctions are spread in longitude. Thus, this study allows us to compare longitudinal variability at a fixed latitude and LST from two independent platforms.
Title: Application of the imaging FPI to 630 nm dayglow observations
Author: John Meriwether, Center for Solar Terrestrial Research, NJIT
Abstract: In this talk I will show that a low-resolution imaging FPI instrument using a high-speed CCD camera or a high-speed CMOS camera can be applied to the intensity observations of the 630nm dayglow or daytime aurora with a very high ratio of signal to noise. The spacer gap would be 0.025 cm, and the aperture 10 cm diameter. The dayglow is typically of the order of 2 kR and the Rayleigh background signal is of the order of 5 megaRayleighs per Angstrom. The annular summing of the FPI ring pattern provides the advantage of sampling the 630 nm dayglow over as many as 3000 pixels. Previous work has centered upon the application of a spectrograph for this purpose with great success. I will show some examples of this from the literature. The imaging FPI would have multiple applications. One example is to observe the polar cusp region during the late afternoon or twilight period which would expand the winter period over which cusp 630nm intensity observations could be made. A second example would be the equatorial region co-located with the Appleton anomaly. A third application would be the observations of the particle precipitation associated with the daytime aurora. It is also possible to use the imaging FPI to observe the OH emissions at 860 nm and 864 nm and from this ratio to infer the OH rotational temperature averaged along the line-of-sight into the dayglow MLT region.
Title: Considerations for analysis and error assessment in multi-decadal data sets
Author: Susan Nossal, University of Wisconsin, Madison
Abstract: We will briefly discuss analysis, calibration, and data uncertainty assessment of the midlatitude multi-decadal hydrogen airglow data set. Ground-based Fabry-Perot observations of Balmer alpha emissions taken from Northern mid-latitudes span multiple solar cycles, facilitating investigation of decadal scale variations, including natural variability in the hydrogen response to solar geophysical changes. We will also include a few other examples from aeronomy and climate science for a broader discussion of challenges, considerations and approaches associated with longer-term data comparisons and assessment of error.
Title: Long term calibration of an all-sky imager using stars
Author: Jeff Baumgardner, Center for Space Physics, Boston University
Abstract: 12 years of data from an All-Sky Imager (ASI) at el Leoncito, Argentina were used to make a time history of the responsivity [RSec/DN] of the system. A set of standard stars are followed across the sky for a given night and a plot of Rsec/dn vs zenith distance (zd) are made. These graphs (after an azimuthally symmetric vignetting function is removed) have a shape similar to the extinction function for that night. The responsivity factor at the zenith was followed for 12 years. The responsivity was seen to vary ~20% over the years due to dust accumulation and periodic cleaning by rainstorms or by human intervention.
This is where the final summary workshop report will be.
Upload presentation and link to it here. Links to other resources.
- Add links to your presentations here, including agendas, that are uploaded above. Please add bullets to separate talks. See further information on how to upload a file and link to it.