At the structure of virtually all air-borne, ground-based and space-based Earth observations is the TRF, or Terrestrial Reference Frame. The TRF depends on an accurate estimation of the geocenter of the Earth (the center mass of the Earth). Nevertheless, one complication is that the geocenter is constantly altering with respect to the Earths surface. By utilizing a network of ground stations geared up with telescopes and lasers that fire pulses at particular satellites, scientists can determine where the geocenter of the Earth is at any provided time to a couple of millimeters to ensure our Earth observations are precise.
Video Transcript:
[Upbeat Music] Narrator: Where are you today?
Or even better, how do you understand where you are?
Probably you are utilizing an app that is utilizing a GPS to pinpoint where exactly you are on Earth.
What you might not know is that behind your preferred navigation app is an invisible facilities of systems working together to supply you a precise place, and that the structure of these systems is a TRF or terrestrial recommendation frame.
Dr. Stephen Merkowitz: So referral frame is essential to any type of mapping, area, placing, navigation application.
Storyteller: Thats Dr. Stephen Merkowitz, NASAs Space Geodesy Project Manager.
Merely put, geodesy is the science of measuring and comprehending the shape of the Earth, its orientation in space and gravity, and how they change over time.
Dr. Stephen Merkowitz: Earth is continuously altering shape, and the land masses are constantly moving.
Its at small levels, so its not something you would feel, you know, yourself.
Were constantly measuring whats occurring with the Earth as a whole and the Earths surface.
Storyteller: To do this, NASA and global partners keep an eye on measurement stations dotted throughout the globe that help us determine where, how much and in which instructions our world is changing.
Dr. Stephen Merkowitz: Since the Earths surface area is constantly moving, any measurement isnt just in a repaired coordinate system. It requires to consider the truth that its associated to the landmass and where that landmass is at any provided time.
Storyteller: And just like a coordinate system plotted on a notepad, the TRF has an origin or in this case, the center mass of the Earth– called the geocenter.
Due to the fact that of this, numerous Earth observing satellites orbit around the center mass of the Earth, not the Earths geographical.
So its vital for researchers to determine where that is to make sure our Earth observations are precise.
Dr. Stephen Merkowitz: One problem is that the center mass of the Earth is constantly altering in time with regard to the Earths surface.
Storyteller: Earthquakes, volcanoes, or perhaps climatic pressure changes all effect where exactly the center mass of the Earth is.
By using a network of ground stations geared up with telescopes and lasers that fire pulses at specific satellites, scientists can determine where the geocenter of the Earth is at any provided time to a couple of millimeters.
Dr. Stephen Merkowitz: This is a really crucial item that we produce for orbiting satellites, particularly for missions that are either doing mapping the gravitational field of the Earth or mapping the height of the Earths surface area, whether it be sea, greenery, or land level.
We make that offered to the general public, we use the data there to create a higher level of items, geodetic products, that can be used by NASA objectives for numerous clinical applications.
Given that this is a worldwide measurement, NASA cant do it alone.
We count on the international neighborhood to provide all the data thats required to offer global coverage.
Storyteller: Having a concurred upon international system is what makes determining our world possible, whether it be from land, sea, air, or perhaps space.