Renseignements généraux

Nº de série

504

Nº de partie

1

Nombre total de parties

1

Ou

S/O

Brevets

S/O

Description générale

Coated and uncoated metal, rubber power cord

Dimensions

Remarque : Cette information reflète la taille générale pour l’entreposage et ne représente pas nécessairement les véritables dimensions de l’objet.

Longueur

48,0 cm

Largeur

46,0 cm

Hauteur

40,0 cm

Épaisseur

S/O

Poids

S/O

Diamètre

S/O

Volume

S/O

Lexique

Groupe

Exploration et levé

Catégorie

Mesure-position

Sous-catégorie

S/O

Fabricant

Ou

University

Pays

Canada

État/province

Ontario

Ville

Toronto

Contexte

Pays

Canada

État/province

Inconnu

Période

Purchased by NRCan in 01-01-1996

Canada

The Canadian Geodetic Long Baseline Interferometry (CGLBI) research is Canada's representative to the International VLBI Service for Geodesy and Astrometry. Modern Geodesy relies on astronomical and space based techniques, namely Very Long Baseline Interferometry (VLBI), GPS (the Global Positioning System), SLR (Satellite Laser Ranging) and LLR (Lunar Laser Ranging). IAG commission VIII (International Coordination of Space Techniques for Geodesy and Geodynamics (CSTG)) discusses the different space techniques in its status report for 1996, and argues that "Only VLBI is capable of defining the Celestial Reference Frame, which serves as the inertial system in satellite geodesy. Long term stability of UT1 UTC and of precession/mutation can only be guaranteed by this technique." Their summary states: "It is clear from the scientific point of view that VLBI, Laser Ranging (SLR and LLR), and satellite microwave techniques are indispensable as contributors to space geodesy." The Canadian contribution to Geodetic VLBI is substantial. The Algonquin Radio Observatory is a leading site for Geodetic VLBI with a very long history of observations. Continued operation of the Yellowknife antenna is important for studies of the North American Plate. The Canadian developed S2 VLBI system is a complete system consisting of recording terminals, data acquisition systems, playback terminals and a correlator.

Fonction

Allowed the researchers to very accurately determine changes in the Earth and the Earth's place in space.

Technique

S2 DAS: This Canadian designed data acquisition system was adopted internationally to define the International Terrestrial Reference Frame (ITRF) a key element in mapping especially in the era of Global Positioning System satellites. The US system, in comparison, took 1 slice per frequency while the S2 only had 1 slice and skipped along the frequencies being scanned. This was much more efficient and technically a much simpler system but each system still cost $250,000. A Russian version uses yet another technique with slightly less stable time-base system, hence slightly less precise. The HP and Datum instruments were state-of-the-art when produced and had long term stability as a time keeper but were not as stable on the short term. Their roles in the system was to provide a very precise time record so that records from different observatories could be compared directly to determine the shifts in position of the continents and of the Earth in space.

Notes sur la région

Inconnu

Détails

Marques

White and red label reads: "CANADA [maple leaf flag]"/ Labels below read: "S2 S[/]N: 504"/, "TAM 'B'", GSD 0042", "APPLY 120V AC ONLY"/ White label on other side panel reads: "CSA SPARE"/ White label on third side reads: "TAM "B"/ (Lower unit)", white label upper right corner: "GSD 0042"/

Manque

S/O

Fini

Black coated metal with uncoated metal parts. White print and white labels with black print. Labelled cable connections.

Décoration

S/O