#geodetic

TomKrajci 🇺🇦 🏳️‍🌈 🏳️‍⚧️KrajciTom@universeodon.com
2025-12-06

Atmospheric refraction, due to the different temperature/altitude profile in the atmosphere at different times of day...makes distant mountains appear taller or shorter.

The attached photo is a comparison of what I shot yesterday afternoon and this morning. The camera was set up within inches of the same location for both shots, and those mountains are between 50 and 120 miles away...so I'm saying that any parallax effect from camera location is essentially zero.

I have annotated with arrows where it's easy to make a comparison of how the near and far ridge lines overlap differently in the two photos.

This is a follow up to:
universeodon.com/@KrajciTom/11

Imagine the care that was needed to conduct surveys before the GPS/GNSS era:
explorersweb.com/the-five-men-

"The Great Theodolite built by Troughton & Simms in London stood nearly 1.5m high, had a horizontal circle one meter in diameter, and could read angles to a single second of arc. Moving it required 30 porters and sometimes elephants."

"The reduction of Nicolson’s observations was a colossal task. Each ray from each station had to be corrected for instrumental error, for temperature and pressure, and for the curvature of the Earth. Above all, they needed to correct for atmospheric refraction, which at those distances could amount to six or seven minutes of arc and change from hour to hour."

#Atmosphere #Refraction #Physics #Math #GIS #Datum #Survey #Geodetic #Map #Optics #Science #Parallax #Cool #NewMexico #Theodolite

A comparison of two photos of the same distant mountain ridges. Arrows show places where the ridgelines overlap in different ways in the two photos. The top photo is grayscale, the bottom one is color.The great theodolite. Photo: Survey of India Archives
2025-10-22

"The absence of #Canadian #geodetic observatories has direct consequences for its own space program. #RADARSAT, once a symbol of Canadian leadership in space, is today the only major commercial synthetic aperture radar mission not supported by the International Laser Ranging Service." - Anusuya Datta

2025-10-22

" #Canada’s failure to invest in modern #geodetic infrastructure has left it dependent on foreign systems...on the key networks of Very Long Baseline Interferometry (VLBI) and Satellite Laser Ranging (SLR) — the backbone of the world’s geodetic infrastructure — Canada looks no different from Africa..." gogeomatics.ca/canadas-geodesy

On the global maps of geodetic observatories , Canada, the world’s second-largest country, is almost a blank space. Europe, Japan, and Australia are dense with dots. The United States dominates North America.
2025-09-04

#FYI #NASA #CERES #Geodetic #oceanHeat

via #‪LeonSimons‬ ‪@leonsimons.bsky.social‬

To cite Ronny Chieng: It goes up! Even if you flip the chart upside down, it still goes UP!

"the near-term forcing increase might be much higher than models suggest"

bsky.app/profile/leonsimons.bs

#climate #ClimateScience #climatechange #ClimateEmergency #ClimateDisruption #ExtremeWeather #polycrisis #EcosystemCollapse #systemcollapse #ecocide #fossilfuels #Co2Emissions #methane #GreenhouseGases #KeepitInTheGround

2024-11-18

Job - Alert 🚀

🔍 POSTDOCTORAL RESEARCHER (F_M_X) FOR GENESIS-D PROJECT

Deadline: 2024-11-24

Location: Germany, Oberpfaffenhofen, Bayern

APPLY: academiceurope.com/job/?id=574

#AerospaceEngineering #Astronomy #geodesy #Postdoc #ProgrammingLanguages #geodetic

Technische Universität Münchentu_muenchen@wisskomm.social
2024-09-09

Researchers employ advanced #geodetic techniques to understand the river #Isar‘s behavior, #sediment transport, and the impact of human activities on this unique #ecosystem: go.tum.de/846800

#geodesy

📷S.Höcht

💧🌏 Greg CocksGregCocks@techhub.social
2024-04-17

As A USGS Employee Working In Spatial Data: hehehehehehehehe
--
xkcd.com/2920/ <-- link to XKCD cartoon
--
"The standard North American NAD83 coordinate system is misaligned from the actual Earth, off-centre by about 7 feet. Someone knows where I am, and I'm in the wrong place."
#GIS #spatial #mapping #humour #humor #datums #coordinatesystems #NAD83 #NAVD88 #mappymeme #survey #USGS #NGS #benchmark #surveymarker #NorthAmerica #geodetic #geodesy
@XKCD

cartoon - XKCD - survey marker - https://xkcd.com/2920/
WeAreSeismicaweareseismica
2024-02-22

Geodetic Rates versus Geologic Slip Rates: Are They Equal?

Gauriau & Dolan explore the circumstances under which geologic slip rates and a geodetic slip-deficit rates may align or diverge.

Read more at: doi.org/10.26443/seismica.v3i1

2023-09-14

@jon I have only passed through a couple of times, never spent any longer time there. The weather is nice, yes. Walked along the river and admired the bridge in the early morning the 3rd when I was going the other direction. Didn’t see the Lenin plaque but saw a couple of info posters about the #Struve #geodetic arch from 1816–1855. Which was interesting in a nerdy way.

Oh, and #Tornio has a bar called “Little Berlin”. Will have to visit that. I expect disappointment, though…

2023-09-11
DISK
Geodetic Survey of Canada disk.
N 49° 05.043 W 125° 50.478
10U E 292542 N 5440688
Top of Radar Hill Tofino
#Tofino #Canada #Geodetic #Surveying
A metal disc embedded in granite rock with text indicating the exact location of the disk.
Alaska Native NewsAKNativeNews
2023-07-11

This Day in Alaskan History-July 11th, 1921
[the_ad id="30587"]

July 11 1921

[the_ad id="37544"]
alaska-native-news.com/july-11
#11 #1921 down

💧🌏 Greg CocksGregCocks@techhub.social
2023-06-22

Rampant Groundwater Pumping Has Changed the Tilt of Earth’s Axis
--
scientificamerican.com/article <-- shared technical article
--
doi.org/10.1029/2023GL103509 <-- shared paper
--
“ • Earth's pole has drifted toward 64.16°E at a speed of 4.36 cm/yr during 1993–2010 due to groundwater depletion and resulting sea level rise

• Including groundwater depletion effects, the estimated drift of Earth's rotational pole agrees remarkably well with observations…”
--
#GIS #spatial #mapping #geodetic #geodesy #earth #water #research #earthaxis #axis #pole #gravity #remotesensing #groundwater #pumping #global #waterresources #watersecurity #watersupply #sealevelrise #subsidence #earthobservation #aquifer

Galactic JourneyGalacticJourney
2023-02-21

[Feb. 21, 1968] Launched yesterday, 202 and 203 in very different orbits. The first may be a scientific probe, and the other, based on orbit and altitude, may be a .

Matthew Dockreyattoparsec@clacks.link
2023-02-05

Orogeny update: Experimenting with adding some lat/long grids to the inset map. I like how it emphasizes the properties of the different projections, but I'm not sure it's worth it.

But time for bed now.

#cartography #geodetic #tectonics #gamedev

Screenshot: A large, cartoonish planet with very simple continents on the left. On the right there is a play button and a bunch of checkboxes on the top, and at the bottom is an inset map showing the planet in a Robinson/Natural Earth projection, with grid lines every 30 degrees of latitude and longitude.
💧🌏 Greg CocksGregCocks@techhub.social
2023-01-12

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