scholarly journals Transformations between the Slovenian and international terrestrial reference frames

2021 ◽  
Vol 65 (03) ◽  
pp. 361-384
Author(s):  
Sandi Berk ◽  
Klemen Medved
Keyword(s):  
Reference Frame ◽  
Reference Frames ◽  
Kinematic Model ◽  
Terrestrial Reference Frame ◽  
Model Transformations ◽  
Specific Character ◽  
High Quality ◽  
Terrestrial Reference Frames

The current Slovenian terrestrial reference frame (D96-17) is a static frame based on GNSS technology. An additional transformation connecting it with the new realisation of ETRS89 accepted by EUREF (D17) gives the D96-17 a specific character. In order to ensure a high-quality national terrestrial reference frame, connection to the current realisation of ITRS is needed. This change is particularly important in the light of the intended transition to the semi-kinematic terrestrial reference frame, supported by a national geo-kinematic model. Transformations between the current national and international terrestrial reference frames are discussed in detail in the present paper. Processes, equations, and parameters of datum transformations are given in both directions (forward and inverse), step-by-step and direct ones, rigorous and simplified (approximate). Furthermore, an analysis of coordinate differences between current Slovenian and international terrestrial reference frames and an analysis of coordinate errors for various simplifications of transformation between both reference frames are given. This allows users to choose an optimal transformation solution to meet their requirements. The role and importance of transformations under consideration in the positioning procedures and the precise navigation are also addressed.

scholarly journals Concept for Reference Frames in Geodesy and Geodynamics: The Reference Directions

1979 ◽  
Vol 82 ◽  
pp. 175-175
Author(s):  
Erik W. Grafarend ◽  
Ivan I. Müller ◽  
Haim B. Papo ◽  
Burkhard Richter
Keyword(s):  
Reference Frame ◽  
Reference Frames ◽  
Current Knowledge ◽  
Terrestrial Reference Frame ◽  
Observation Point ◽  
Terrestrial Reference Frames ◽  
Space And Time ◽  
The Earth ◽  
Least Squares Adjustment ◽  
Rigid Earth

Modern high accuracy measurements of the non-rigid Earth are to be referred to four-dimensional, i.e., time and space-dependent reference frames. Geodynamics phenomena derived from these measurements are to be described in a terrestrial reference frame in which both space and time-like variations can be monitored. Existing conventional terrestrial reference frames (e.g., CIO, BIH) are no longer suitable for such purposes.The ultimate goal of this study is the establishment of a reference frame, moving with the Earth in some average sense, in which the geometric and dynamic behavior of the Earth can be monitored, and whose motion with respect to inertial space can also be determined.The study is conducted in two parts. In the first part problems related to reference directions are investigated, while the second part deals with positions, i.e., with reference origins. Only the first part is treated in this paper.The approach is based on the fact that reference directions at an observation point on the Earth's surface are defined by four fundamental vectors (gravity, Earth rotation, etc.), both space and time variant. These reference directions are interrelated by angular parameters, also derived from the fundamental vectors. The interrelationships between these space and time-variant angular parameters are illustrated in a commutative diagram–tower of triads, which makes the derivation of the various relationships convenient.In order to determine the above parameters from observations (e.g., laser ranging, VLBI) using least squares adjustment techniques, a model tower of triads is also presented to allow the formation of linear observation equations. Although the model tower is also space and time variant, these variations are described by adopted parameters representing our current knowledge of the Earth. For details, see Bulletin Géodésique, end of 1978.

scholarly journals Astrometry and Geodesy from VLBI

1993 ◽  
Vol 156 ◽  
pp. 159-171
Author(s):  
C. Ma ◽  
J. L. Russell
Keyword(s):  
Reference Frame ◽  
Reference Frames ◽  
Radio Sources ◽  
Dual Frequency ◽  
Terrestrial Reference Frames ◽  
Vlbi Observations ◽  
Using Data ◽  
Celestial Reference Frame ◽  
Right Ascension ◽  
Better Than

Dual frequency Mark III VLBI observations acquired since 1979 by several geodetic and astrometric observing programs have been used to establish precise celestial and terrestrial reference frames. The program to establish a uniformly distributed celestial reference frame of ∼400 compact radio sources with optical counterparts was begun in 1987. Some 700 sources have been considered as part of this effort and a preliminary list of ∼400 has been observed. At present, 308 sources have formal 1σ errors less than 1 mas in right ascension and 308 have similar precision in declination. The astrometric results include some data acquired for geodetic purposes. The geodetic results using data to September, 1992 include the positions of 105 sites with formal 1σ horizontal errors generally less than 1 cm at 1992.6 and the velocities of 64 sites with formal 1σ horizontal errors generally better than 2 mm/yr.

High-precision GNSS-positioning in GSK-2011 reference frame

2019 ◽  
Vol 944 (2) ◽  
pp. 2-14 ◽  
Author(s):  
N.A. Bovshin
Keyword(s):  
Reference Frame ◽  
High Precision ◽  
Reference Frames ◽  
Geodetic Network ◽  
Terrestrial Reference Frame ◽  
Reference Station ◽  
Gnss Positioning ◽  
Processing Procedure ◽  
Gnss Observations ◽  
Correct Processing

The paper deals with a high-precision geodetic network densification by means of GNSS based geodetic solutions, in the view of the fact that the initial data are represented in different reference frames. Indeed, reference station positions are represented in GSK-2011 terrestrial reference frame whereas GNSS satellites` ephemeris are represented in other reference frames, such as ITRFs, WGS84, etc. Two methods are considered in the paper to provide GNSS observations with a correct processing procedure

scholarly journals Formation of The International Celestial Reference Frame

1998 ◽  
Vol 11 (1) ◽  
pp. 281-286
Author(s):  
C. Ma ◽  
E.F. Arias ◽  
T.M. Eubanks ◽  
A.L. Fey ◽  
A.-M. Gontier ◽  
...  
Keyword(s):  
Reference Frame ◽  
Reference Frames ◽  
Terrestrial Reference Frame ◽  
Naval Research ◽  
Dual Frequency ◽  
Cooperative Effort ◽  
Space Navigation ◽  
Vlbi Observations ◽  
Crustal Dynamics ◽  
Celestial Reference Frame

The goal of the work described here is to create the definitive catalogue for the new International Celestial Reference Frame (ICRF) using the best data and methods available at the time the work was done. This work is the joint cooperative effort of a subgroup of the IAU Working Group on Reference Frames which was formed expressly for this purpose in February 1995. The authors of this report constituted the subgroup. A fuller account of this report can be found in the introduction to the ICRF catalog (IERS 1997). The ICRF of 608 sources presented here is based on essentially all the VLBI observations accu-mulated over about 15 years in several worldwide programs. Dual frequency Mark III data have both geodetic and astrometric applications. Most of the data (95% of nearly 2 million observations) were acquired primarily for geodetic purposes. The major geodetic programs include: NASA’s Crustal Dynamics Project/Space Geodesy Program and USNO’s NAVEX sessions for the terrestrial reference frame, as well as IRIS, NAVNET and NEOS sessions for monitoring Earth rotation. The geodetic programs have used the brightest radio sources, gradually concentrating on the most com-pact as sensitivity improved. These geodetic sources were also the foundation of astrometric work because of the large number of observations for the ~150 most commonly used. The astrometric programs which densify the sky include the Radio-Optical Reference Frame sessions done by US Naval Research Laboratory (NRL) and USNO and the space navigation efforts of Jet Propulsion Laboratory (JPL).

scholarly journals CQSSP: A New Technique for Establishing the Tie Between the Stellar and Quasar Celestial Reference Frames

1991 ◽  
Vol 127 ◽  
pp. 341-347
Author(s):  
T. Schildknecht ◽  
I. Bauersima ◽  
U. Hugentobler ◽  
A. Verdun ◽  
G. Beutler
Keyword(s):  
Reference Frame ◽  
Earth Rotation ◽  
Reference Frames ◽  
Terrestrial Reference Frame ◽  
Optical Observations ◽  
Artificial Satellites ◽  
Satellite Orbits ◽  
Earth Rotation Parameters ◽  
A New Technique ◽  
Celestial Reference Frame

AbstractUsing artificial satellites as transfer objects the project “Coupled Quasar-Satellite-Star Positioning” represents an independent method for linking quasar and stellar reference frames. Optical observations of close approaches between reference stars and satellites yield satellite positions in the stellar reference frame. On the other hand high precision satellite orbits in the International Earth Rotation Service (IERS) terrestrial reference frame are obtained from laser or radiometric observations. Using IERS earth rotation parameters and adopted transformation models the satellite and eventually the star positions can be expressed in the IERS quasar celestial reference frame. In this paper we describe the CQSSP project and assess its capability for providing an accurate tie between tho two metioned celestial reference frames.

The U.S. is replacing NAD83 with NATRF2022: what this means for Canada

GEOMATICA ◽  
2019 ◽  
Vol 73 (3) ◽  
pp. 74-80
Author(s):  
Caroline Erickson ◽  
Geoff Banham ◽  
Ron Berg ◽  
Joey Chessie ◽  
Michael Craymer ◽  
...  
Keyword(s):  
Reference Frame ◽  
North American ◽  
Reference System ◽  
Reference Frames ◽  
Terrestrial Reference Frame ◽  
The U.S

In 2022, the U.S., as part of its reference system modernization, will replace its North American Datum of 1983 (NAD83) with a new North American Terrestrial Reference Frame (NATRF2022), creating 1.3 to 1.5 m horizontal coordinate differences at the Canada–U.S. border with respect to Canada’s NAD83(CSRS). Never before have such significant differences existed between our two countries’ reference frames. This paper reviews why the U.S. is making this change and then looks at Canada’s situation with respect to reference frames. There are compelling reasons for Canada to follow suit and move to NATRF2022 within a decade, but there are also major challenges. Whether or not Canada follows the same path, there is much work to be done to prepare Canada for the U.S.’ move to NATRF2022. This paper is intended as a first step to inform the Canadian geospatial community of the U.S.’ move to NATRF2022 and what it means for Canada.

Realizing ITRF-Consistent Continental-Scale Geodetic Reference Frames

2021 ◽  
Author(s):  
Demian Gomez ◽  
Michael Bevis ◽  
Dana Caccamise
Keyword(s):  
Reference Frame ◽  
Reference Frames ◽  
Object Oriented ◽  
Terrestrial Reference Frame ◽  
Object Oriented Programming ◽  
Helmert Transformation ◽  
Trajectory Model ◽  
Continental Scale ◽  
International Terrestrial Reference Frame ◽  
The Relationship

<p>To achieve a regional or continental-scale reference frame that is a densification of the International Terrestrial Reference Frame (ITRF), one can use a set of fiducial GPS / GNSS stations in the ITRF and regional frames.  Predicting coordinates in the realization epoch using the fiducial stations’ trajectory parameters in the ITRF and applying a Helmert transformation aligns the regional solution’s polyhedron onto the ITRF.  This paper shows inconsistencies in the regional realization of ITRF when the fiducial stations’ trajectory model ignores the periodic terms, resulting in a periodic coordinate bias in the regional frame.  We describe a generalized procedure to minimize this inconsistency when realizing any regional frame aligned to ITRF or any other ‘primary’ frame. We show the method used to realize the Argentine Geodetic Positions (Posiciones Geodésicas Argentinas, POSGAR) reference frame and discuss its results. Inconsistencies in the vertical were reduced from 4 mm to less than 1 mm for multiple stations after applying our technique.  We also propose adopting object-oriented programming terminology to describe the relationship between different reference frames, such as a regional and a global frame. This terminology assists in describing and understanding the hierarchy in geodetic reference frames.</p>

Allocentric to Egocentric Spatial Switching: Impairment in aMCI and Alzheimer's Disease Patients?

2018 ◽  
Vol 15 (3) ◽  
pp. 229-236 ◽  
Author(s):  
Gennaro Ruggiero ◽  
Alessandro Iavarone ◽  
Tina Iachini
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Reference Frame ◽  
Reference Frames ◽  
Memory Task ◽  
Spatial Representations ◽  
The Novel ◽  
Spatial Memory Task ◽  
Switching Condition ◽  
Normal Controls

Objective: Deficits in egocentric (subject-to-object) and allocentric (object-to-object) spatial representations, with a mainly allocentric impairment, characterize the first stages of the Alzheimer's disease (AD). Methods: To identify early cognitive signs of AD conversion, some studies focused on amnestic-Mild Cognitive Impairment (aMCI) by reporting alterations in both reference frames, especially the allocentric ones. However, spatial environments in which we move need the cooperation of both reference frames. Such cooperating processes imply that we constantly switch from allocentric to egocentric frames and vice versa. This raises the question of whether alterations of switching abilities might also characterize an early cognitive marker of AD, potentially suitable to detect the conversion from aMCI to dementia. Here, we compared AD and aMCI patients with Normal Controls (NC) on the Ego-Allo- Switching spatial memory task. The task assessed the capacity to use switching (Ego-Allo, Allo-Ego) and non-switching (Ego-Ego, Allo-Allo) verbal judgments about relative distances between memorized stimuli. Results: The novel finding of this study is the neat impairment shown by aMCI and AD in switching from allocentric to egocentric reference frames. Interestingly, in aMCI when the first reference frame was egocentric, the allocentric deficit appeared attenuated. Conclusion: This led us to conclude that allocentric deficits are not always clinically detectable in aMCI since the impairments could be masked when the first reference frame was body-centred. Alongside, AD and aMCI also revealed allocentric deficits in the non-switching condition. These findings suggest that switching alterations would emerge from impairments in hippocampal and posteromedial areas and from concurrent dysregulations in the locus coeruleus-noradrenaline system or pre-frontal cortex.

scholarly journals Reference frames in spatial communication for navigation and sports: an empirical study in ultimate frisbee players

2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Steven M. Weisberg ◽  
Anjan Chatterjee
Keyword(s):  
Reference Frame ◽  
Reference Frames ◽  
Spatial Information ◽  
Spatial Reference ◽  
Spatial Reference Frames ◽  
The North ◽  
Communication Task ◽  
Spatial Communication ◽  
Spatial Domains ◽  
Ultimate Frisbee

Abstract Background Reference frames ground spatial communication by mapping ambiguous language (for example, navigation: “to the left”) to properties of the speaker (using a Relative reference frame: “to my left”) or the world (Absolute reference frame: “to the north”). People’s preferences for reference frame vary depending on factors like their culture, the specific task in which they are engaged, and differences among individuals. Although most people are proficient with both reference frames, it is unknown whether preference for reference frames is stable within people or varies based on the specific spatial domain. These alternatives are difficult to adjudicate because navigation is one of few spatial domains that can be naturally solved using multiple reference frames. That is, while spatial navigation directions can be specified using Absolute or Relative reference frames (“go north” vs “go left”), other spatial domains predominantly use Relative reference frames. Here, we used two domains to test the stability of reference frame preference: one based on navigating a four-way intersection; and the other based on the sport of ultimate frisbee. We recruited 58 ultimate frisbee players to complete an online experiment. We measured reaction time and accuracy while participants solved spatial problems in each domain using verbal prompts containing either Relative or Absolute reference frames. Details of the task in both domains were kept as similar as possible while remaining ecologically plausible so that reference frame preference could emerge. Results We pre-registered a prediction that participants would be faster using their preferred reference frame type and that this advantage would correlate across domains; we did not find such a correlation. Instead, the data reveal that people use distinct reference frames in each domain. Conclusion This experiment reveals that spatial reference frame types are not stable and may be differentially suited to specific domains. This finding has broad implications for communicating spatial information by offering an important consideration for how spatial reference frames are used in communication: task constraints may affect reference frame choice as much as individual factors or culture.

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