Clock Correction

Clock Correction

 

the difference between the exact time at any moment and the clock reading at that moment. A clock correction indicates the number of hours, minutes, seconds, and fractions of a second it is necessary to algebraically add to a clock reading in order to obtain the exact time. Clock correction can be found by reference to sidereal or mean solar time, either local, standard (zone), or universal. Calculation of clock correction is one of the basic problems of practical astronomy, and time services conduct routine astronomical observations to determine such corrections. The clock correction changes over the course of time; this change in the course of a single 24-hour period is called the diurnal clock rate.

References in periodicals archive ?
Digital phase-locked loop (DPLL) and Kalman filter both have been widely used as the clock tracking and clock correction schemes for the similar structure and properties.
The satellite clock correction is calculated based on parameters transmitted in the satellite navigation message.
The accuracies of orbit and clock correction products and error models to be used in determination have significant importance on the point positioning accuracies to be achieved in PPP method.
To achieve better curve fitting, here, we design the "satellite-clock-aided curve fitting" strategy which applies the satellite clock correction. First, we extract the high-precision satellite clock information from the International GNSS Service (IGS) clock file.
Car clockers are so blatant that they openly advertise their "car clock correction" services on the internet.
Caption: Figure 4: RTS clock correction and prediction result (PRN 08, January 18, 2016).
The REFSV field contains the satellite clock correction. The software obtains this information in one of two different ways, depending upon the OEM receiver board in use.
We introduced Kalman filter (Strang and Borre, 1997) in the final phase of data processing for dynamic recursive estimation of set of unknown parameters--site coordinates, correction to initial ambiguities and actual receiver clock correction.
Tender issueThis EXPRO+ procurement is part of the NAVISP Programme under Elelment 1 Work Plan 2017.The object of the activity is to design develop and validate/verified a GNSS space receiver capable to perform on board precise orbit determination (P2OD) in real time using precise GNSS orbit and clock corrections provided either by Geostationary satellites (thus allowing on board autonomy w.r.t to ground stations).
Clock corrections are given as offsets to the Broadcast Ephemeris satellite clock corrections (http://igs.org/rts/products).
Where [[DELTA].sub.C] contains various clock corrections, r is a vector from the barycentre to the telescope, [??] is a unit vector pointing from the barycentre to the pulsar, c is the speed of light, d is the distance to the pulsar, D is the interstellar dispersion constant,/is the radio frequency, [A.sub.E[?]] is the Einstein delay comprised of the gravitational red shift and time dilation, [[DELTA].sub.S[?]] is the Shapiro delay characterising the curvature of space time near the Sun and [[DELTA].sub.A[?]] is the aberration delay as a result of the Earth's rotation (Bell, J.F., 1996; Kaspi V.M; Lorimer D., 2008)
The StarFire system uses a network of more than 50 GPS reference stations around the world to compute GPS-satellite orbit and clock corrections. These corrections are broadcast via three geosynchronous satellites to the GPS receiver, enabling precise real-time navigation without the need for a ground base station.