A Satellite Navigation and Global Positioing Systems forum. Sat Nav Banter

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Go Back   Home » Sat Nav Banter forum » GPS and Sat Nav Newsgroups » sci.geo.satellite-nav (Global Satellite Navigation)
Site Map Home Authors List Search Today's Posts Mark Forums Read Web Partners

sci.geo.satellite-nav (Global Satellite Navigation) (sci.geo.satellite-nav) Discussion of global navigation satellite systems (GNSS). Topics include the technical aspects of GNSS operation, user experiences in the use of GNSS, information regarding GNSS products and discussion of GNSS policy (such as GPS selective availability).

Part 2: Nightmare on GIS Street Accuracy, Datums, and Geospatial Data



 
 
Thread Tools Display Modes
  #1  
Old May 24th 13, 12:00 AM posted to sci.geo.satellite-nav
Sam Wormley[_2_]
external usenet poster
 
Posts: 775
Default Part 2: Nightmare on GIS Street Accuracy, Datums, and Geospatial Data

Part 2: Nightmare on GIS Street Accuracy, Datums, and Geospatial Data
http://geospatial-solutions.com/part...ospatial-data/


  #2  
Old May 24th 13, 01:06 AM posted to sci.geo.satellite-nav
Alan Browne
external usenet poster
 
Posts: 1,339
Default Part 2: Nightmare on GIS Street Accuracy, Datums, and Geospatial Data

On 2013.05.23 19:00 , Sam Wormley wrote:
Part 2: Nightmare on GIS Street Accuracy, Datums, and Geospatial Data
http://geospatial-solutions.com/part...ospatial-data/


Good article.


--
"A Canadian is someone who knows how to have sex in a canoe."
-Pierre Berton

  #3  
Old May 24th 13, 06:54 AM posted to sci.geo.satellite-nav
oriel36[_2_]
external usenet poster
 
Posts: 144
Default Part 2: Nightmare on GIS Street Accuracy, Datums, and Geospatial Data

On May 24, 12:00*am, Sam Wormley wrote:
Part 2: Nightmare on GIS Street – Accuracy, Datums, and Geospatial Data







http://geospatial-solutions.com/part...-street-accura...


Tell me Sam,how many times does the Earth rotate ,to the nearest full
rotation,in proportion to the 4 times it makes an orbital circuit of
the Sun ?.

These sat-nav bozos concerned with 'accuracy will give the Earth 4
phantom rotations over 4 years which makes it impossible to apply
rotation to plate tectonics which requires a maximum equatorial speed
of 1037.5 miles per hour at the Equator.Want to see a real nightmare -

"The angular speed of Earth's rotation in inertial space is (7.2921150
± 0.0000001) ×10−5 radians per SI second (mean solar second).
Multiplying by (180°/π radians)×(86,400 seconds/mean solar day) yields
360.9856°/mean solar day, indicating that Earth rotates more than 360°
relative to the fixed stars in one solar day. Earth's movement along
its nearly circular orbit while it is rotating once around its axis
requires that Earth rotate slightly more than once relative to the
fixed stars before the mean Sun can pass overhead again, even though
it rotates only once (360°) relative to the mean Sun. Multiplying the
value in rad/s by Earth's equatorial radius of 6,378,137 m (WGS84
ellipsoid) (factors of 2π radians needed by both cancel) yields an
equatorial speed of 465.1 m/s, 1,674.4 km/h or 1,040.4 mi/h. Some
sources state that Earth's equatorial speed is slightly less, or
1,669.8 km/h.This is obtained by dividing Earth's equatorial
circumference by 24 hours. However, the use of only one circumference
unwittingly implies only one rotation in inertial space, so the
corresponding time unit must be a sidereal hour. This is confirmed by
multiplying by the number of sidereal days in one mean solar day,
1.002 737 909 350 795,which yields the equatorial speed in mean solar
hours given above of 1040 miles per hour ".

http://en.wikipedia.org/wiki/Earth_rotation

You poor,poor people - had you followed the proper astronomical
principles where rotations/orbital circuits transfer loosely into days/
years and thereby stuck to the 24 AM/PM system in tandem with the Lat/
Long system a mess like this would never have occurred and researchers
would be discussing the uneven rotational gradient of the fluid
interior between equatorial and polar latitudes which is crucial for
bind the spherical deviation of the planet with plate tectonics
through differential rotation.



 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT. The time now is 12:08 AM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.SEO by vBSEO 2.4.0
Copyright 2004-2018 Sat Nav Banter.
The comments are property of their posters.