Geodesy

Geodesy is the science of accurately measuring the geometric shape of the earth, its orientation in space, and its gravity field, and monitoring how these properties change over time. Space geodesy is the geodesy that is practiced using extra-terrestrial assets such as satellites and quasars.

Haystack scientists and engineers focus on two aspects of space geodesy: geodetic VLBI, or measuring positions on the earth and the earth’s rotation and orientation, and polar geodesy, or measuring polar ice in the Arctic and Antarctic.

Spotlight Projects

Fortaleza: The Next Generation of VLBI Telescopes

Haystack is designing and installing the signal chain for a new NASA radio telescope in Fortaleza, Brazil.

SGIP: Antarctic Seismo-Geodetic Ice Penetrator

Monitoring the response of ice shelves in Antarctica to ocean forces.

Co-located techniques and atmospheric ties

Developing a method to incorporate constraints from atmospheric structure to improve the accuracy of relative site position estimates and ITRF combinations.

All Geodesy Projects

Haystack geodesy

Geodetic VLBI

Our geodesy teams use a technique pioneered at Haystack in the 1960s called very long baseline interferometry (VLBI). VLBI allows data from pairs of telescopes all across the globe to be combined, resulting in measurements much more precise than those of a single telescope. VLBI is widely used for many scientific applications (such as taking images of black holes!) in addition to geodesy. Haystack’s space geodesy program develops technologies and makes observations for precisely calculating Universal Time, or UT1, based on the earth’s rotation speed and angle. These measurements are essential for keeping GPS and other global navigation systems accurate.

Polar geodesy

Our polar geodesy program develops high-precision GPS instruments to study glaciers, icebergs, sea ice, and ice shelves in the Arctic and Antarctic. Data from these installations are relayed back to Haystack by satellites for analysis. Knowing where and how the polar ice is melting, drifting, deforming, and fracturing is crucial for cryosphere, oceanography, and climate science studies.

Researchers

John Barrett

Christopher Eckert

Pedro Elosegui

Dan Hoak

Dhiman R. Mondal

Arthur Niell

Violet Pfeiffer

Michael Poirier

Ganesh Rajagopalan

Chester A. Ruszczyk

Michael Titus

Recent Publications

Synthesis of the distribution of subsidence of the lower Ganges-Brahmaputra Delta, Bangladesh. Earth-Science Reviews. (2022). DOI: https://doi.org/10.1016/j.earscirev.2021.103887

Model-based Performance Characterization of Software Correlators for Radio Interferometer Arrays. Publications of the Astronomical Society of the Pacific. (2022). DOI: https://doi.org/10.1088/1538-3873/ac8dc2

Analytic Approximations of Scattering Effects on Beam Chromaticity in 21‐cm Global Experiments. Radio Science. (2022). DOI: https://doi.org/10.1029/2022RS007558

All publications