NASA's Next Generation Space Geodesy Network

Journal of Geodesy

NASA maintains and operates a global network of Very Long Baseline Interferometry (VLBI), Satellite Laser Ranging (SLR), and Global Navigation Satellite System (GNSS) ground stations as part of the NASA Space Geodesy Program. The NASA Space Geodesy Network (NSGN) provides the geodetic products that support Earth observations and the related science requirements as outlined by the US National Research Council (NRC 2010, 2018). The Global Geodetic Observing System (GGOS) and the NRC have set an ambitious goal of improving the Terrestrial Reference Frame (TRF) to have an accuracy of 1 millimeter and stability of 0.1 millimeters per year, an order of magnitude beyond current capabilities. NASA and its partners within GGOS are addressing this challenge by planning and implementing modern geodetic stations co-located at existing and new sites around the world. In 2013, NASA demonstrated the performance of its next-generation systems at the prototype next-generation core site at NASA's Goddard Geophysical and Astronomical Observatory in Greenbelt, Maryland. Implementation of a new broadband VLBI station in Hawaii was completed in 2016. NASA is currently implementing new VLBI and SLR stations in Texas and is planning the replacement of its other aging domestic and international legacy stations. In this article, we describe critical gaps in the current global network and discuss how the new NSGN will expand the global geodetic coverage and ultimately improve the geodetic products. We also describe the characteristics of a modern NSGN site and the capabilities of the next-generation NASA SLR and VLBI systems. Finally, we outline the plans for efficiently operating the NSGN by centralizing and automating the operations of the new geodetic stations.

2006

Activities of this Working Group include the investigation of the status quo and the development of a plan for full network integration to support improvements in terrestrial reference frame establishment and maintenance, Earth orientation and gravity field monitoring, precision orbit determination, and other geodetic and gravimetric applications required for the long-term observation of global change. This integration process includes the development of a network of fundamental stations with as many co-located techniques as possible, with precisely determined intersystem vectors. This network would exploit the strengths of each technique and minimize the weaknesses where possible. This paper discusses the organization of the working group, the work done to date, and future tasks.

2008

The Global Geodetic Observing System-GGOS, places the utmost importance on the development, maintenance and wide distribution of an International Terrestrial Reference Frame (ITRF) with very stringent accuracy attributes. We present here results from simulation studies aimed at designing optimal global geodetic networks to support GGOS. At present, our goal is an origin definition at 1 mm or better at epoch and a temporal stability on the order of 0.1 mm/y, with similar numbers for the scale and orientation components. These goals are based on extensive deliberations within the Earth science community. In particular, oceanographers, a prime user group that these products are intended for, require this level of accuracy and temporal stability in order to address sea level rise issues with confidence. The stability, integrity and applicability of the ITRF are directly related to how accurately we can account for mass redistribution during the analysis and reduction process of the data used for its development. Long wavelength variations of the gravity field driven by these mass redistributions produce geometric effects that are manifested as changes in the origin and orientation between the instantaneous and the mean reference frame. This insidious coupling between the product and the reference with respect to which the product is generated makes the problem extremely complex and sensitive to systematic errors. An uneven distribution of the stations realizing the ITRF results in biases and distortions in the combined product due to the dissimilarity of the combined networks and their de facto lopsided overlap. Poor geometry results in increased correlations between the similarity transformation parameters, leading again to biased and unstable results. In this presentation, we are examining SLR's contribution in establishing the optimal network along with VLBI, since these two techniques alone are sufficient for this task. Using simulations of geodetic data that we expect to collect with the future geodetic networks, we look at various designs of several co-located networks and the resulting accuracy in the origin, scale and orientation definition of the realized ITRF.

Questions to objects / Vragen aan objecten , 2024

This bilingual artist book contains an essay by Vlad Ionescu on the project of the Belgian designer Nedda El-Asmar : http://www.nedda.be It concerns Nedda El-Asmar's artistic experiment around the artistically transformative processes of melting donated gold and turning it into a newly designed object. While the economic value of gold will never get lost (because gold is perfectly recyclable), the question remains: what is the artistic value of the design itself? For more information on the project, feel free to contact Nedda El-Asmar: [email protected]

Educational Theory, 2023

ince the 1970s, the concepts of “lifeworld” and “everyday life” have been part of thediscourse of social pedagogy and social and educational work in general. Xavier Úcar’s objective in thisarticle is to generate and communicate socio-pedagogical knowledge that helps social pedagogues tobuild socio-educational relationships that are more effective, more sustainable, more satisfactory, andultimately richer in terms of both experiences and learning for participants. A conceptually oriented,nonsystematic analysis procedure was used to conduct this research. The procedure involved an in-depthinvestigation of documents that focus on the two target areas of this study: (1) social pedagogy, and (2)lifeworld and everyday life. The results describe the theoretical background of lifeworld and everydaylife, discuss the development of the perspective of “lifeworld orientation” within the framework of socialpedagogy in Germany, and analyze how everyday life is understood through actions undertaken by socialpedagogues. These results provide ideas for mapping the essential dimensions of everyday life from theperspective of social pedagogy

Current Issues in Language Planning, 2023

This paper proposes a framework for multilingual language-in-education policy implementation, offered as a critically constructive response to India’s recent National Education Policy 2020 (GOI, 2020). Rooted in India’s existing educational language policy, our linguistically inclusive ‘Languages for Learning’ (LFL) framework is, we believe, structurally flexible, socioculturally feasible, economically viable and academically relevant. It aims to foster equity and also to ensure first language support and cognitive independence. Before presenting the framework, we critically review the multilingual policy guidance offered in NEP 2020, then lay out a theoretical foundation for the LFL framework based primarily on current translanguaging theory, and also discuss the history of India’s much maligned three-language formula (TLF), which forms the core of language policy in India. The framework itself is presented with reference to specific contextual challenges in India that may also serve to indicate its relevance for other multilingual contexts around the world. As such, the LFL framework is offered as a more multilingually-appropriate alternative to the reductive construct of ‘Medium of Instruction’, which itself originates in the monolingual habitus of historically outdated language-in-education policy theory. We invite critical evaluations of the utility of our framework, both for India and other multilingual contexts.

2019

Boilers and pressure vessels are widely used in the industrial environment. They require attention from the project to the end of its useful life, regulated by international standards. The objective of this study was to demonstrate some procedures for the inspection of a boiler by analyzing its databook and verify its compliance with the American Society of Mechanical Engineers (ASME) and NR-13 (Regulatory Standard 13), current legislation used in Brazil for the management of these equipments. Sheet metal thickness calculations and MAWP (Maximum Allowable Working Pressure) were performed to establish the minimum safety criteria. The thickness measurement of the plate was performed using an ultrasonic meter. The data obtained evidenced agreement with the current norms for boilers, but in the databook it was verified the absence of the calculation memory used in the project to obtain the minimum thickness of the sheet metal, essential information according to NR-13, for the safe use the equipment. After inspection it was found that the boiler meets the minimum operating conditions according to the calculations made from the available information, and even after 25 years of operation, it has the structural requirements for use in accordance with the ASME project standard.