Linked Questions
32 questions linked to/from Difference between projection and datum
18
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2
answers
70k
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Is WGS84 a Coordinate system or projection system? [duplicate]
WGS84 is often referred to as a "projection system" and sometimes it is confusing to me about what a "projection system" is and where WGS84 falls in one.
Could someone please clear that up for me?
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3
votes
2
answers
2k
views
What is the difference between a datum and an ellipsoid? [duplicate]
For example I am converting from ECEF to lla using
def ecef_to_lla(x, y, z):
lla = pyproj.Proj(proj='latlong', ellps='WGS84', datum='WGS84')
ecef = pyproj.Proj(proj='geocent', ellps='WGS84', ...
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1
vote
0
answers
170
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Are ellipsoid and datum the same? [duplicate]
Are the datum and the ellipsoid the same? What is a Datum?
The Earth is shaped like a flattened sphere. This shape is called an
ellipsoid. A datum is a model of the earth that is used in mapping.
...
- 11
1
vote
0
answers
119
views
Geographic coordinate system and datum [duplicate]
I am bit confused about datums used to define a localised coordinate system for a specific area. Definitions say that, datum defines how a certain well-established point (i.e., reference point) on ...
- 51
0
votes
0
answers
110
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what is the difference between the Geographic coordinate, transformed coordinate and screen coordinate [duplicate]
What is the difference between the Geographic coordinate, transformed coordinate(projected) ,cartesian coordinate, and screen coordinate? Is there a live example?
And what is the association between ...
- 803
25
votes
7
answers
4k
views
Spatial reference for dummies?
Can anyone recommend a good reference or tutorial that explains the principles of spatial references, projections, and coordinate systems?
We are a small team of programmers working with GIS ...
21
votes
5
answers
25k
views
What is projection of WGS84 in GIS software? [duplicate]
WGS84 is a reference ellipsoid that determines coordinates of every point on Earth using latitude, longitude and height about the its surface.
This ellipsoid is often used as a base to make maps. ...
- 1,545
31
votes
2
answers
115k
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Understanding difference between Coordinate System and Projection?
Can somebody please explain what is the difference between the Coordinate system (WGS 84 for example) and a Projection (Universal Transverse Mercator for example)?
What is the difference between a ...
- 1,147
7
votes
1
answer
11k
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Latitude, longitude, projections, CRS [closed]
I'm confused about the following basic points:
Do lat/long points have a projection or are they projection agnostic?
Do these points live in a sphere or a plane?
I understand that projections are ...
- 231
0
votes
2
answers
4k
views
How would I convert this point to WKID 4326?
This is a point in Brewster, MA, USA. How would it be converted to WKID 4326?
324299.3348436486, 832511.5939650714
- 103
4
votes
2
answers
8k
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Converting NAD83 (epsg:4269) to WGS84 (epsg:4326) using pyproj
I'm trying to convert US census data (NAD83) to WGS84.
I know the difference between the two is quite minor, but trying to apply the transformation using pyproj does not do anything. e.g.:
from ...
- 141
7
votes
1
answer
2k
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Vertical Datum and Projection
Does vertical datum get projected? I feel a bit confused with the concept of the vertical datum and doing a projection.
- 71
4
votes
3
answers
4k
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Advanced Digitizing Panel Not Enabled When Map View is in Geographic Coordinates
I am trying to use the advanced digitizing panel with a new line geometry layer. I am using QGIS 3.0.3
The QGIS documentation states:
"The tools are not enabled if the map view is in geographic ...
- 187
2
votes
1
answer
4k
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Difference between WGS_1984_UTM_33N and GCS_WGS_84
What is the difference between:
a map that has a projected coordinate system of WGS_1984_UTM_33N, a
geographic coordinate system of GCS_WGS_1984, and a datum of
D_WGS_1984
a map that has no projected ...
- 31
2
votes
3
answers
2k
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Understanding map projection coordinate systems
I have been playing around with a variety of map projections for the purposes of transforming between various representations.
The thing that I still don't quite understand is how to interpret the (x,...
- 121