Writing a research paper on how the tilt of earth's axis affects surveys. Any info toward this subject would be helpful. Thanks!
I would be interested to see your findings.?ÿ
I can't think of anything off hand since we are not elliptic centered.
I suppose the changing of the ephemeris and the shifting of constellations can be considered.?ÿ
Polaris has been the north star since modern surveying, but Vega will become the north star and was in the past.?ÿ
Being so brand new here joining today, you might try posting your 'research' question over in the GNSS Geodesy forum. Is that how 'research' is conducted today, just announce you're writing a paper and ask everyone to send you all the information? My guess is you might be a flatearther coming here to f around, but I might be wrong too. Maybe you could be a bit more informative in the formation of your inquiry. What's the name of your paper and where are you intending to publish it?
The tilt of the axis has very little effect on land surveys. Most of this work is done by measuring from monuments on the ground, so you would get the same results if the tilt were different.
In the past surveyors often took sun shots to get azimuth for their measurements, and a very few still do occasionally. For this you need data on the sun's apparent position, which not only changes with time of day, but also with the seasons due to the tilt of the axis.
Geodetic surveying has little need to consider the tilt, because such work now relies mostly on Global Navigation Satellite Systems such as GPS. The satellite orbits are approximately determined without considering tilt, only needing to consider the relationship of earth and sun for small effects of the sun's gravity.
Did you have a more specific question?
I apologize I did not know there was proper etiquette for forums.. I stumbled upon this web page searching about my paper topic. I am a student and am simply writing a three page research paper for school. I thought there would be someone with intelligence and respect that may have a suggestion or thought to help broaden my thinking.
A specific affect is: When the original surveyors surveyed USA, they sighted polaris, to set their magnetic declination.
So, variation of earth's relationship to the north star, allowed for a small amount of change. But, this is not very much. Hard to measure with magnetic compass. Negligible, imho.
N
, they sighted polaris
Yes. I should have said sun and Polaris.
Polaris appears to change azimuth by about 2 degrees depending on time and season. That is easily significant in a land survey.
Thanks for your input... I guess I didn't pick a very good topic.
Interesting, I have seen some info on this but I will have to look into it a little further. Thanks!
The earth's orientation in space, (irrespective of its relationship to the sun) is what matters for Polaris. It just happens that Polaris is currently the closest easily visible star to the alignment of the axis. In the times of early civilization, there was a different "north star" but the axis wobbles over thousands of years.
Pole stars over history due to precession of the axis. Again, this has little to do with the tilt with respect to the orbit around the sun.
From Wikipedia
Considering the earth's change in axis tilt, although measurable, GPS is a Earth Centered Earth Fixed (ECEF) reference frame so the main problem is where is exactly 0,0,0 (floating around @ 2.5 meters presently).?ÿ Well within parameters to provide sub cm accuracy concerning surface accuracy.?ÿ The stars no longer act as a reference.
Although not exactly the change in tilt, you might want to research the history of the array of latitude observatories that were established around the world around 1900 to measure the wobble of the earth on its axis. They remained operational until around 1980, for the most part. That wobble must be accounted for when using geodetic quality GPS/GNSS measuring techniques.
https://en.wikipedia.org/wiki/International_Latitude_Observatory
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I would not expect a lot of responses after posting an open-ended request for raw research material, and then snarkily putting down the very people you appear to be asking for help. And there is always etiquette for forums, which I am sure you knew already.
Fortunately for you, there are a lot of folks here who will help you anyways.
You are still in school, so consider this a learning opportunity: in the future, ask some specific questions that show you have a basic grasp of the topic, rather than pitching it out there, which makes it look like you are fishing for someone to do the legwork for you. It also helps us understand your topic better, as some of the members here have extensive knowledge in very specific areas - if we don't know exactly what you are after the right person may not reply. That's really all we need to help you out, and is a pretty low bar to clear.
@lars-engineering, where are you going to school and what class are you taking that includes this topic of the earth's axis being tilted ..... tilted with respect to what? No need to apologize. Just come forward with a little bit more information and you will get more back. Here is a big spoonful for you -
https://jessekozlowski.wordpress.com/2020/04/09/geodesy/&source=gmail&ust=1587318372576000&usg=AFQjCNG1wdn37tyZ47xPiuC2N9zo_fgeL A"> https://jessekozlowski.wordpress.com/2020/04/09/geodesy/ ?ÿ
Look for publications like this one ...
INTRODUCTION TO GEODETIC ASTRONOMY 1981
http://www2.unb.ca/gge/Pubs/LN49.pdf
