Northings, eastings, and heights are not coordinates, they are ordinates. When ordinates are paired they become COordinates...
Trivia note... For some of us, hearing "north coordinate" can induce stress resulting in a mild stroke ..
Northings, eastings, and heights are not coordinates, they are ordinates. When ordinates are paired they become COordinates...
Trivia note... For some of us, hearing "north coordinate" can induce stress resulting in a mild stroke ..
Thank you for that clarification. My inner pedant appreciates it. But now it brings up a question: what do we call a three-value grouping of (N, E, Z)?
Triordinate? Co-coordinate?
By looking straight down on a globe, the Equator looks like a circle. View the same globe directly from the side and it looks like a line.
By looking straight down on a globe, the Equator looks like a circle. View the same globe directly from the side and it looks like a line.
Now do great circles...
Triordinate? Co-coordinate?
From Wikipedia.
A point in the plane may be represented in homogeneous coordinates by a triple (x, y, z) where x / z and y / z are the Cartesian coordinates of the point.
Are you ai, or human?
you sound ai to me
blood or electrons?
I’ve seen these type of posts on other forums and it screams ARTIFICIAL “intelligence” to me
maybe I’m wrong
Coordinates expressed as northings (N) and eastings (E) define the location of a point in a 2D-rectilinear system derived from ellipsoidal latitudes and longitudes via projection parametersparticular to its politically-defined location. Points expressed as N and E values are not linked to the geocenter.
The relationship between any two points in a rectilinear system can be derived through plane trigonometry.
In the US the main implementation of rectangular coordinate systems is the State Plane Coordinate System. Prior to the adoption of the North American Datum of 1983, the National Geodetic Datum of 1927 expressed SPCS coordinates as X and Y values.
Please note that a 3-dimensional coordinate systems have been developed to express latitude, longitude and ellipsoid height values (for a point or a vector) in terms X,Y,Z (earth-centered earth-fixed) with their values being with respect to geocenter. Local Geodetic Horizon coordinates expressed in North, East and Up can be derived from known latitudes and longitudes plus XYZ coordinates using rotation matrices.
Over-explaining as usual… To damned hot to get out of the house.
You are assuming to much, northerings and eating don't necessarily have any particular relationship to "ellipsoidal latitudes and longitudes (derived) via projection parameters.
The image above is from the Mathworks site. When dealing with different types of dimensional data “we” would refer to coordinate pairs or coordinate triplets.
Personally, with the advent of technologies allowing three-dimensional positioning (even before GPS), I cannot see why users continue to use 2D systems like the SPCS.
See Burkholder’s The 3D Global Spatial Data Model.
@thebionicman I would argue that a northing or easting could be stated in isolation, but it is nonetheless inherently part of a system of coordinates.
An analogy would be describing the individual deeds of a 'conspirator' (and not a 'spirator'), who by definition forms part of a group.
I'm not sure of the purpose your project is intended to serve, but that's a good first draft. Here are two thoughts:
An easting/northing is the plane equivalent of a latitude/longitude: each is a coordinate, which amounts to a value in terms of a distance or angle respectively, in the set of coordinates that their coordinate system specifies.
Yes, a coordinate is a distance and an angle, but you omitted a key element. The distance and angle are from the origin of the coordinate system. In a sense, you are mixing two representations: rectangular and polar coordinates. That's not necessarily bad depending on your purpose and your audience, but the wording and the concepts it represents deserves some careful thought.
... we could say that a north-south line has the same easting value.
This one trips up many people. Let me give you an example using UTM Zone 17 coordinates.
Latitude = 36.0; Northing = 3,984,064 meters
Longitide = -81.5; Easting = 453,936 meters
Keeping Longitude constant at -81.5 and moving north b 1/2 degree:
Latitude = 36.5; Northing = 4,038,524 meters
Longitude = -81.5; Easting = 455,222 meters
Note that in moving due north; ie, keeping longitude constant, the Easting changed by roughly 1,300 meters.
Thus, a north-south line on an ellipsoidal representation of the earth does not produce a line with constant Easting on a map. There's a lot of mathematics that explains this characteristic, but the one that you should explore is the convergence of the meridians.
You can explore this relationship further here: NGS Coordinate Conversion and Transformation Tool (NCAT) (noaa.gov)
You're on a good track, just don't ignore the details.
@terminologist The logic may loosely apply, but the words 'ordinate' and 'coordinate' have edtablished and distinct meanings. An ordinate is a line, plane, or axis. A coordinate is the point where two or more of these intersect or interact in a way that defines a specific point.
I am unfamiliar with your definition of ordinate.
I do not see it as consistent with that in the NGS Geodetic Glossary (located here: https://www.ngs.noaa.gov/CORS-Proxy/Glossary/xml/NGS_Glossary.xml )
Some screen captures regarding coordinates and ordinates from that source follow:
The last image above is from the Cambridge on-line dictionary. This is the sense I remember an ordinate being defined.
Defining a point via a northing and easting raises the question with respect to what?
I do not understand the comment posted by @aliquot which I read to indicate that plane coordinates are not necessarily linked to the underlying ellipsoidal coordinates i.e. latitude and longitude. Is that what you (@aliquot) are saying? If so, they would be equivalent to “assumed” coordinates.
The spelling and definition of ordinate have been fairly consistent back to new latin. I did expand on the dictionary definition to include other types of coordinates that surveyors deal with.
