WESTPAC 1 (Western Pacific Laser Tracking Network) is a small, passive laser ranging satellite for geodetic measurements.
At the Western Pacific Laser Tracking Network (WPLTN) Executive meeting in Moscow on 2
December 1995, it was announced that Electro Optic Systems (EOS) had entered into a joint
project with the Russian Space Agency (RSA) to construct and launch a new SLR satellite
(WESTPAC-1, formely known as WPLTN-1) designed to overcome the limitations of all present
targets in relation to millimeter geodesy. Initially, this satellite was referred to as
WPLTN-1. It is currently designated WESTPAC-1 and very similar in design to GFZ-1.
Its main immediate purpose is to provide the best possible target for the WPLTN
stations and, by implication, the Keystone Project constructed by Communications Research
Laboratory (CRL) of the Japanese Ministry of Posts and Telecommunications.
The WESTPAC satellite is covered with recessed retroreflectors of the Russian Fizeau
design to permit only one retroreflector to contribute to the return. On average, 0.7
corner cubes contribute to the return, and therefore the return signal fades in and out as
different reflectors come into view. The satellite is well-suited for advanced two color
ranging experiments.
WESTPAC is a passive satellite with the only instrumentation onboard is the
retroreflector array. The WESTPAC retroreflector array is designed so that:
- Only a single corner-cube will reflect on any shot
- Its response will be optimized for 1.54 micron wavelength, to provide for fully eyesafe
ranging at any power
- The center-of-mass correction is accurate to 0.5 millimeters
- To verify indisputably the existence or otherwise of the Fizeau effect.
.png)
