File:GRAIL-image0011-fr.jpg
From Wikimedia Commons, the free media repository
Jump to navigation
Jump to search
GRAIL-image0011-fr.jpg (444 × 296 pixels, file size: 58 KB, MIME type: image/jpeg)
File information
Structured data
Captions
Captions
Add a one-line explanation of what this file represents
Summary
[edit]DescriptionGRAIL-image0011-fr.jpg |
English: The Lunar Gravity Ranging System (LGRS) is the scientific payload of the GRAIL lunar spacecraft.
The LGRS is responsible for sending and receiving the signals needed to accurately and precisely measure the changes in range between the two orbiters. The LGRS consists of an Ultra-Stable Oscillator (USO), Microwave Assembly (MWA), a Time-Transfer Assembly (TTA), and the Gravity Recovery Processor Assembly (GPA). The USO provides a steady reference signal that is used by all of the instrument subsystems. Within the LGRS, the USO provides the reference frequency for the MWA and the TTA. The MWA converts the USO reference signal to the Ka-band frequency, which is transmitted to the other orbiter. The function of the TTA is to provide a two-way time-transfer link between the spacecraft to both synchronize and measure the clock offset between the two LGRS clocks. The TTA generates an S-band signal from the USO reference frequency and sends a GPS-like ranging code to the other spacecraft. The GPA combines all the inputs received from the MWA and TTA to produce the radiometric data that is downlinked to the ground. In addition to acquiring the inter-spacecraft measurements, the LGRS also provides a one-way signal to the ground based on the USO, and is transmitted via the X-band Radio Science Beacon (RSB). The steady-state drift of the USO is measured via the one-way Doppler data provided by the RSB. |
Date | |
Source | http://solarsystem.nasa.gov/grail/spacecraft.cfm |
Author | NASA |
Licensing
[edit]Public domainPublic domainfalsefalse |
![]() |
This file is in the public domain in the United States because it was solely created by NASA. NASA copyright policy states that "NASA material is not protected by copyright unless noted". (See Template:PD-USGov, NASA copyright policy page or JPL Image Use Policy.) | ![]() |
![]() |
Warnings:
|
File history
Click on a date/time to view the file as it appeared at that time.
Date/Time | Thumbnail | Dimensions | User | Comment | |
---|---|---|---|---|---|
current | 08:31, 2 July 2011 | ![]() | 444 × 296 (58 KB) | Pline (talk | contribs) |
You cannot overwrite this file.
File usage on Commons
There are no pages that use this file.
File usage on other wikis
The following other wikis use this file:
- Usage on fr.wikipedia.org
- Usage on he.wikipedia.org
Metadata
This file contains additional information such as Exif metadata which may have been added by the digital camera, scanner, or software program used to create or digitize it. If the file has been modified from its original state, some details such as the timestamp may not fully reflect those of the original file. The timestamp is only as accurate as the clock in the camera, and it may be completely wrong.
_error | 0 |
---|
Hidden categories: