'Atomic time' diaporamas de présentation

General Concepts of Time and Frequency Metrology

General Concepts of Time and Frequency Metrology. Michael Lombardi lombardi@nist.gov. NIST Boulder Laboratories. Date and Time-of-Day records when an event happened Time Interval duration between two events Frequency rate of a repetitive event.

943 views • 89 slides

Overview of Time and Frequency Metrology

Overview of Time and Frequency Metrology. Michael Lombardi lombardi@nist.gov. NIST Boulder Laboratories. Date and Time-of-Day records when an event happened Time Interval duration between two events Frequency rate of a repetitive event. Types of Time and Frequency Information.

856 views • 83 slides

Planning

Planning Chapter 11.1-11.3 Some material adopted from notes by Andreas Geyer-Schulz and Chuck Dyer Overview What is planning? Approaches to planning GPS / STRIPS Situation calculus formalism [revisited] Partial-order planning Planning problem

1.23k views • 64 slides

Distributed Systems Concepts and Design Chapter 11: Time and Global States

Distributed Systems Concepts and Design Chapter 11: Time and Global States. Steve Wallis, Raymond Ho, Bruce Hammer. 11.1: Introduction. Time and Global States Time is a quantity we need to measure accurately Synchronization of Clocks Development Of Algorithms Relative Order Of Events

865 views • 59 slides

Evolution of Timescales from Astronomy to Physical Metrology

Dennis D. McCarthy U. S. Naval Observatory. Evolution of Timescales from Astronomy to Physical Metrology. TIMEKEEPING BASICS. Repeatable Phenomenon Length between repetitions Beginning of the repetition Names for the successive repetitions Timescales driven by timekeeping technology.

826 views • 47 slides

ASEN 5050 SPACEFLIGHT DYNAMICS Time Systems, Conversions, f & g

697 views • 47 slides

Time Scales UT0, UT1, EAL, TAI, UTC

390 views • 33 slides

ASEN 5070: Statistical Orbit Determination I Fall 2014 Professor Brandon A. Jones

ASEN 5070: Statistical Orbit Determination I Fall 2014 Professor Brandon A. Jones Lecture 3: Basics of Orbit Propagation. Announcements. Monday is Labor Day! Homework 0 & 1 Due September 5 I am out of town Sept. 9-12

375 views • 29 slides

Naming

Naming. CSCI 4780/6780. Attribute-based Naming. Flat and structured names provide location transparency Structured names are also human-friendly Increasingly, users and application want to locate for resources based on features, contents, characteristics Web search P2P search.

363 views • 22 slides

Naming

Naming. CSCI 4780/6780. Attribute-based Naming. Flat and structured names provide location transparency Structured names are also human-friendly Increasingly, users and application want to locate for resources based on features, contents, characteristics Web search P2P search.

301 views • 22 slides

Leap Seconds

Leap Seconds. Dennis McCarthy U. S. Naval Observatory. Definition of Seconds. Rotational Second 1 / 86,400 of mean solar day Ephemeris Second First used in 1956 1/31,556,925.9747 of tropical year 1900 Length of year based on 19 th century astronomical observations. Atomic Second.

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372 views • 18 slides

Pulsars and time scales

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294 views • 18 slides

Last Class: Naming

Last Class: Naming. Name distribution: use hierarchies DNS Iterative versus Recursive name resolution. The DNS Name Space. The most important types of resource records forming the contents of nodes in the DNS name space. DNS Implementation.

153 views • 15 slides

Time

Time=number of repetitions of a periodic phenomenon. Different types: Rotation of the Earth: sideral and universal Orbital motion of Moon and planets: ephemeris, dynamical Frequency of nuclear radiation: atomic time. Time. Sideral time = hour angle of the vernal equinox Types

139 views • 4 slides