Lmst

I set up a cheap and dirty homepage for #measuringtheearth using Linktree and short.io to help anybody interested in navigating my repository on the history of #geodesy to find their way: http://measuring.earth/home

#histsci #digitalhistory

after listening to a talk by @joguldi on AI and historical objectivity and receiving a hint in this direction on the chat, I started playing around -- multiple ethical qualms notwithstanding -- with NotebookLM. I have now set up a publicly accessible notebook with my #MeasuringtheEarth dataset on the history of #geodesy (a complete collection of digitized conference minutes and reports of the Internationale Erdmessung, 1862-1912, also available on GitHub: http://measuring.earth/IAG).

As long as you have a Google account, you can explore the dataset and ask questions about the history of geodesy using AI: http://measuring.earth/notebook. As soon as I have time and resources, I will look for freely accessible alternatives. BTW, I'm open for suggestions on how to set up a publicly accessible #AI interface that draws on #GitHub (and in perspective #Codeberg) to go through such a collection in a way comparable to NotebookLM

#histsci #digitalhistory

🚀 Exactly seven years ago (on 22 May 2018, at 9:47 p.m. CEST), it was “Liftoff for GRACE Follow-On.” 🚀

➡️ https://www.aei.mpg.de/168977/successful-launch-of-the-climate-research-mission-grace-follow-on?c=39681

Soon afterwards, the satellite geodesy mission consisting of two spacecraft reached its orbit around Earth. On board is a new type of laser interferometer developed in Hanover, Germany. It is used to measure the Earth's gravitational field and monitor the melting of polar ice cap and changes in groundwater levels.

The first observational data were received in the summer of 2018. Since then, the system has been running reliably and delivering high-precision measurements.

ℹ️ https://www.aei.mpg.de/39681/grace-follow-on

Film: NASA's Jet Propulsion Laboratory (https://gracefo.jpl.nasa.gov/resources/77/grace-fo-launches-aboard-a-spacex-falcon-9/)

#GRACEFollowOn #Satellites #Laser #Geodesy #ClimateChange #OTD #ThrowbackThursday

@bobthetraveler
The geodetic context may be the most important thing about #Avebury.
Ancient Monument Latitudes Evidence Accurate Astronomy
https://jqjacobs.net/geodesy/ancient_monument_latitudes.html
#Neolithic #Archaeology #Geodesy

Avebury aerial image depicting the one-seventh of circumference latitude baseline, jqjacobs.net image.

Do you want to contribute to an open source project?
Do you like/enjoy/love #GIS , #maps , #cartography , #surveying , #topography or #geodesy ?
Do you know C/C++? (this is optional)

You are very welcome to the communities of #GDAL or PROJ developers.
Join us!

https://gdal.org
https://proj.org

Wait a second: are you already coding in C++ or Python using these libraries? What are you waiting for!?

Hint: mailing lists are a good starting point ;)

#cpp #gischat

For #BlackHistoryMonth: #mathematician & geodesist Gladys West (née Brown 1930)! Shown with satellite tracks & 3 satellites important to her career: Seasat, GEOS-3 & a GPS satellite. Her work, using math to precisely model the shape of Earth, laid the groundwork for GPS! Born to sharecropper parents in Virginia, she graduated with a Math BSc in ‘52 then MSc at VSU in ‘55. 🧵1/n

#linocut #printmaking #womenInSTEM #BlackInSTEM #histSci #geodesy #EarthScience #Math

My linocut portrait of Gladys West with 3 satellites important to her career in indigo in from of world map with satellites tracks in blue.

Reshma Krishnan Sudha is a PhD student in the “Space Interferometry” group.

She works on GRACE and its successor GRACE Follow-On (GRACE-FO), two highly successful satellite gravimetry missions for Earth observation. Satellite gravimetry, which involves the measurement of spatial and temporal changes in the gravity field caused by mass variations from space, provides a unique opportunity to study mass transport and improve our understanding of the Earth system. Changes in the mass distribution within and between Earth's atmosphere, oceans, groundwater, and ice sheets serve as fundamental indicators of the large-scale dynamics of the planet.

In GRACE-FO, the Laser Ranging Interferometer was used as a technology demonstrator alongside the established microwave-based ranging measurement. It uses laser interferometry to measure distance variations between satellites with nanometer precision. Reshma's current work lies in the in-flight characterization of the steering mirror, which is an important component in laser link acquisition procedures and also in the correction of spacecraft misalignment. The other focus is on building a breadboard optical bench assembly for optical beat note generation with flight-like beam parameters.

ℹ️ https://www.aei.mpg.de/1110531/reshma-krishnan-sudha

#IDWGS #WomenInSTEM #WomenInScience #Physics #PhD #Space #Geodesy #GRACEFollowOn #Research #Hannover

Sariga Sachit's PhD research in the “Space Interferometry” group focuses on the experimental investigation of various aspects of future laser ranging interferometers on board geodesy satellite missions such as GRACE Follow-On.

After the success of its laser ranging interferometer, the next generations of GRACE-like missions are firmly expected to use laser interferometry as the primary measurement principle. Sariga's project aims at building on the invaluable experience in designing, testing and operating the laser ranging interferometer to further enhance the functionality, performance and reliability of future instruments. She tries to do experimental investigation on link acquisition, auxiliary modulation and absolute ranging that may open new avenues for orbit determination and data processing. She also works on advancements in inter-spacecraft laser interferometry.

ℹ️ https://www.aei.mpg.de/886444/sariga-sachit

#IDWGS #WomenInSTEM #WomenInScience #Physics #PhD #Space #GRACEFollowOn #Geodesy #Research #Hannover

Lately, I've been thinking that there must be some benefits for #geodesy from this research on quantum entanglement. It promises the ability to send encoded timestamps in tiny wave packets of photons, and thus, in principle, allows very accurate time-delay estimation over potentially long distances.
https://www.nature.com/articles/s41566-024-01589-7