Related Experiment Video
Updated: Aug 26, 2025
10:35
Bringing the Visible Universe into Focus with Robo-AO
Published on: February 12, 2013
19.6K
The Australian mixed-mode observing program
Lucia McCallum1, Lim Chin Chuan1, Hana Krásná2
1University of Tasmania, Private Bag 37, Hobart, 7001 Australia.
Journal of Geodesy
|October 3, 2022
Summary
The Australian mixed-mode observing program bridges a gap in geodetic Very Long Baseline Interferometry (VLBI) network upgrades. This novel approach ensures continuous station time series, vital for maintaining global reference frames during the transition to the next-generation VGOS system.
Area of Science:
- Geodesy
- Astronomy
- Earth Science
Background:
- Global geodetic Very Long Baseline Interferometry (VLBI) is transitioning to the next-generation VLBI Global Observing System (VGOS).
- The VGOS upgrade involves a multi-year process, leading to temporary gaps in global network coverage and station data continuity.
- Australian stations ceasing legacy S/X observations create significant data gaps crucial for terrestrial and celestial reference frames.
Purpose of the Study:
- To introduce and evaluate the Australian mixed-mode observing program as a solution to data gaps during the VGOS upgrade.
- To assess the technical details, processing strategies, and geodetic suitability of mixed-mode observations.
- To propose a novel observing mode for integration into standard legacy S/X International VLBI Service (IVS) observations.
Main Methods:
- Conducting mixed-mode VLBI sessions with Australian VGOS stations (Hobart and Katherine) observing legacy S/X VLBI alongside regional stations.
- Documenting the technical specifications and data processing strategies employed during these mixed-mode sessions.
- Comparing geodetic results from mixed-mode sessions with those from standard legacy S/X sessions.
Main Results:
- Mixed-mode sessions successfully enable the continuation of station time series, mitigating data gaps.
- The technical details and processing strategies are described, demonstrating the feasibility of the approach.
- Geodetic results from mixed-mode observations show suitability for maintaining reference frame integrity.
Conclusions:
- The Australian mixed-mode observing program effectively bridges network gaps caused by the VGOS upgrade.
- This novel observing mode supports the continuity of essential geodetic data for reference frame realization.
- The proposed mixed-mode strategy is recommended for adoption into standard legacy S/X IVS observations to prevent degradation of global geodetic results.
Related Concept Videos
01:22Atomic Emission Spectroscopy: Instrumentation
571
The instrumentation of atomic emission spectrometry (AES) involves various components, including atomization devices that convert samples into gas-phase atoms and ions. There are two main types of atomization devices: continuous and discrete atomizers. Continuous atomizers, like plasmas and flames, introduce samples in a constant stream, while discrete atomizers inject individual samples using syringes or autosamplers. The most common discrete atomizer is the electrothermal atomizer.
571
02:30Naturalistic Observations
15.6K
If you want to understand how behavior occurs, one of the best ways to gain information is to simply observe the behavior in its natural context. However, people might change their behavior in unexpected ways if they know they are being observed. How do researchers obtain accurate information when people tend to hide their natural behavior? As an example, imagine that your professor asks everyone in your class to raise their hand if they always wash their hands after using the restroom. Chances...
15.6K
01:02Flame Photometry: Overview
752
Flame photometry, also known as flame emission spectrometry, is a technique used for the qualitative and quantitative analysis of elements present in a sample using a flame as the source of excitation energy. The concept of flame photometry was realized in the early 1860s by Kirchhoff and Bunsen, who discovered that specific elements emit characteristic radiation when excited in flames. The first instrument developed for this purpose was used to measure sodium (Na) in plant ash using a Bunsen...
752
01:16Flame Photometry: Lab
343
In a flame photometer, when a solution like potassium chloride is aspirated into the flame, the solvent evaporates, leaving behind dehydrated salt. This salt dissociates into free gaseous atoms in their ground state. Some of these atoms absorb energy from the flame, leading to their excitation. The excited atoms return to the ground state, emitting photons at characteristic wavelengths. Because only electronic transitions are involved, the resulting emission lines are very narrow. The intensity...
343
01:29Atomic Emission Spectroscopy: Lab
227
AES is a powerful analytical technique, especially effective when used with plasma sources, producing abundant spectra in characteristic emission lines. The Inductively Coupled Plasma (ICP), in particular, yields superior quantitative analytical data due to its high stability, low noise, low background, and minimal interferences under optimal experimental conditions. However, newer air-operated microwave sources are emerging as promising alternatives that could be more cost-effective than...
227
01:20Atomic Emission Spectroscopy: Overview
2.4K
Atomic emission spectroscopy (AES) is an analytical technique used to determine the elemental composition of a sample by analyzing the light emitted from excited atoms. In AES, atoms in a sample are excited to higher energy levels by thermal energy from high-temperature sources, such as plasma, arcs, or sparks. When these excited atoms return to lower energy states, they emit light at specific wavelengths characteristic of each element. The resulting atomic emission spectrum, which consists of...
2.4K