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Questions tagged [terminology]

Indicates questions asking about the use and meaning of specific technical words in GIS.

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How was the term 'Feature' originally defined in GIS? [closed]

Esri defines Feature as a cartographic term: [cartography] Any part of the earth's surface, or anything found on the earth's surface, that can be represented on a map. Features can represent various ...
Rex's user avatar
  • 596
0 votes
0 answers
50 views

What is name/terminology for area in .tif satellite image file which is blank space/not land?

I have some L2 satellite images from an MSI bundle, and I need to produce a mask over the area in the file which is not the image itself - the black part in the image below. What is the technical name ...
Becky W's user avatar
2 votes
1 answer
74 views

What is origin of term "network" in Network Common Data Form (NetCDF) format specification

I see (on Wikipedia) that the NetCDF format evolved from a specification for storing multidimensional data called the "Common Data Format". Semantically... the word "network" has a ...
Zach Smith's user avatar
1 vote
1 answer
789 views

Computing visual "center" of irregular polygon

UPDATE: centroid is fine, my initial implementation was not weighing the edge length. With that fix all is well. I am using the centroid to render a marker in the "center" of a parcel, but ...
ca0v's user avatar
  • 2,951
2 votes
1 answer
134 views

What do you call two isochrone maps that shows the intersection between two points as a "meeting" line?

I've learned today what isochrone maps are but now I sort of want to combine two isochrone so that a line forms right where the maps meet in the middle time wise. As in, if each point travels the same ...
Ramon Smits's user avatar
5 votes
1 answer
1k views

Difference between control point, reference point, and tie point

I georeferenced a map using grid coordinate and road network shapefile (e.g. intersection vertex) as a control point. I didn't acquire a control point through the survey. I use "control point (...
astaga's user avatar
  • 123
1 vote
0 answers
20 views

Is there an equivalent term to 'imagery' in context with maps and cartography?

Is there an equivalent term to imagery in context with maps or cartography? Mappery seems not to exist. (I'm from Germany, and some miles away from being a native-English speaker) To explain that a ...
jaysigg's user avatar
  • 497
14 votes
1 answer
2k views

What does context mean in PyQGIS?

When writing PyQGIS scripts, especially processing script and expression function, I come across the term context. I use it, but I don't know what all contexts mean actually. There are also Qgs***...
Kadir Şahbaz's user avatar
0 votes
1 answer
1k views

Difference between Image layer and Tile Layer

what is the basic difference between Image Layer and Tile Layer? Apart from the documentation....which says below points ol/layer/Tile - Renders sources that provide tiled images in grids that are ...
raghav's user avatar
  • 69
0 votes
1 answer
158 views

Difference and similarities between Intervisibility and Viewshed [closed]

I am just looking for what the difference and similarities for Intervisibility and Viewshed.
Paulito.Bandito's user avatar
2 votes
0 answers
358 views

How do "layer", "feature", "attribute", "field", and "data provider" relate?

I'm new to QGIS, but familiar with Python and PyQt, and am trying to make sense of the terminology of "layer", "feature", "attribute", "field", and "data ...
Lorem Ipsum's user avatar
3 votes
1 answer
215 views

Naming convention for ways of defining direction

The following two conventions for defining direction are very common, but what are they called? 0 at north, clockwise 0 at positive x-axis, counterclockwise Background: I'm writing a function that ...
blupp's user avatar
  • 141
1 vote
1 answer
132 views

Correct terminology to describe regular grid

What is the correct terminology to describe a regular grid of squares based on certain distance in latitude/longitude? I came up with this description: We used regular grid of squares measuring 10' ...
Tomas's user avatar
  • 1,252
10 votes
2 answers
7k views

What is the difference between Ground Sampling Distance (GSD) and spatial resolution?

In research papers on remote sensing, I see some authors referring to spatial resolution (expressed as pixel/distance) and others to Ground Sampling Distance (GSD) (also expressed as pixel/distance). ...
Sytze's user avatar
  • 771
6 votes
3 answers
464 views

Do I necessarily need coordinates for spatial prediction?

Commonly, it is stated that spatial prediction is the same as spatial interpolation, i.e. the estimation of values based on the observations' location: y ~ lon + lat Others state, that spatial ...
Funkwecker's user avatar
1 vote
1 answer
46 views

Does the concept of a map service exist in ArcGIS Online?

I'm new to web GIS. I have created an ArcGIS Online account that contains: Web Maps Feature Layers (hosted) It is my guess that the term feature layer is a synonym for feature service. If that's ...
User1974's user avatar
  • 1,132
-1 votes
1 answer
189 views

Is climate a small-scale or large-scale process? [closed]

This might sound like a stupid question but it bothers me anyway: We distinguish small-scale maps like world-maps and large-scale maps like a map of my local neighborhood. So far, so clear. However, ...
Funkwecker's user avatar
0 votes
0 answers
30 views

What is the term for creating a network from scratch?

As part of my PhD, I developed a simple way of creating a road network splitting up collected coordinates based on where they cross. I know the standard method is to use a shapefile (or similar) as ...
Tom's user avatar
  • 9
1 vote
1 answer
970 views

Meaning of 'bnds' and dimensions in OCO2 v9 L3 data product

I cannot seem to understand what, for example, 'lat_bnds' means? Same go for 'lon_bnds', lat/lon_dimensions. These values come from the structurally flat NCDF4, sourced from the JPL as a custom ...
Nathan's user avatar
  • 33
0 votes
1 answer
26 views

What is getting nearest points between two different but nearby (almost intersecting) datasets called?

I need some terminology help as I am still learning GIS. This is related to, but not the same as, What is getting nearest points between two different but overlaping datasets called? I have two ...
mlane's user avatar
  • 160
1 vote
1 answer
84 views

What is getting nearest points between two different but overlaping datasets called?

I need some terminology help as I am still learning GIS. I have two datasets. One with the address of every fire and it's latitude/longitude of small census tract. One with the location of every ...
mlane's user avatar
  • 160
2 votes
1 answer
1k views

Is there an easy way to say -3.4028234663852886e+38?

A lot of our datasets have a nodata value that is, or close to, -3.4028234663852886e+38. Can anyone think of an easy way to say this out loud when we're discussing things? Even "minus three times ...
jon_two's user avatar
  • 1,874
1 vote
1 answer
1k views

What is Time of Validity in a GPS System?

What is time of validity in a GPS system? For defining time of validity, there are only a limited definitions available. My interpretation for time of validity is the built-in system time (like on ...
Minimalist's user avatar
1 vote
1 answer
74 views

What do you call this combination of two district maps?

My real-world problem is that I want to combine state House and Senate legislative districts so that a user can pick a region (not a point) on a map that is included in both their House and Senate ...
Ed Staub's user avatar
  • 121
1 vote
0 answers
235 views

What is difference between BLOB and tile in GeoPackage?

I'm new to GeoPackage, but wrote some code that will read an image file into a buffer and I then insert that buffer into the GeoPackage as a BLOB. The image files are GeoTIFFs which contain latitude, ...
ViralBacteria's user avatar
2 votes
2 answers
516 views

What is the proper name for the "Venn diagram" of a set of geometries?

Sometimes, you have a set of overlapping geometries, and you want to generate an output like this: Image taken from this answer. The resulting polygons have no overlaps; each region of space is ...
jpmc26's user avatar
  • 1,709
3 votes
1 answer
176 views

Interpreting cell coordinates from DEM?

I'm using Environment Agency DTM LiDAR data which I import into Mathematica in ASCII format to produce ground surface models, sections, etc. The process works fine, but I'm unclear whether the cell ...
Ian Williams's user avatar
2 votes
1 answer
1k views

What does percentile mean in simpleComposite of Google Earth Engine?

I was using 'ee.Algorithms.Landsat.simpleComposite' to composite images, but I'm not sure what does this 'percentile' parameter mean?
jianjianhahaha's user avatar
2 votes
2 answers
521 views

In ArcGIS can a feature set use multiple coordinate systems?

I'm new to learning GIS and ArcMap, but have some confusion about coordinate systems. I thought I understood that there are two main types of coordinate systems, Projected Coordinate Systems which ...
Frank's user avatar
  • 201
2 votes
1 answer
54 views

What part of the Census Block is the County?

I have a list of census blocks for California and I am trying to get the county for each row. If I have a census block of 60070004024003, which 2 digits make up the county FIPS?
Barry Smith's user avatar
9 votes
3 answers
282 views

Adjective meaning "of the same resolution and extent"

Is there a word that can be used to describe two or more raster grids having the same resolution and extent? I'm fishing around with words like "coincident" and "coextensive," but nothing feels quite ...
dbaston's user avatar
  • 13.1k
6 votes
1 answer
534 views

What does LW stand for in liblwgeom of PostGIS?

What does LW stand for in liblwgeom of PostGIS? I could not find any explanation anywhere, or in the source code (mirrored) at https://github.com/postgis/postgis/tree/svn-trunk/liblwgeom
Brian Burns's user avatar
14 votes
1 answer
2k views

What does the ST prefix stand for, e.g. in ST_Polygonize?

I was just curious, and couldn't find any reference to this anywhere - is it Spatial Types? Spatial Topography? Something else?
Brian Burns's user avatar
16 votes
3 answers
15k views

What does M-value represent?

I am trying to wrap my ahead around the meaning of the M-value. I read ESRI's dictionary definition here: https://support.esri.com/en/other-resources/gis-dictionary/term/m-value and was not able to ...
NULL.Dude's user avatar
  • 2,131
2 votes
1 answer
1k views

What is the difference between ArcGIS Desktop and ArcGIS FOR Desktop?

I keep seeing these two categories of software package on the ESRI site but nothing making it clear the difference between what ArcGIS Desktop is vs. ArcGIS For Desktop. I use ArcGIS Desktop (i think)...
user25644's user avatar
  • 1,089
4 votes
1 answer
77 views

How to name this sort of edge?

I'm searching for a certain pathfinding algorithm which considers a certain sort of branch in the network. However, I find it difficult to define my search term as I do not know how this certain kind ...
i.i.k.'s user avatar
  • 1,575
2 votes
1 answer
253 views

Agreed Upon Name for Rows in an Attribute Table

Is there an agreed upon name for the rows in an attribute table, perhaps one that would apply across different GIS software platforms? Esri uses "records" here, for example. They also have the ...
reevesii's user avatar
  • 1,519
4 votes
2 answers
6k views

What is the difference between Key-Point, Tie-Point in Photogrammetry?

I'm looking into the reports & the Mechanism of UAV Photogrammetry software like Pix4D and AgiSoft. These two words are mentioned in a lot of support documentation, but they are defined no-where. ...
Devdatta Tengshe's user avatar
0 votes
1 answer
1k views

Difference between files of extension .asc, .asc.aux.xml, .aux and .rrd?

I have received ASCII data from a client. These ASCII files have been created from LiDAR data. For each tile there are 4 different file types: Filename.asc Filename.asc.aux.xml Filename.aux ...
Mike's user avatar
  • 424
5 votes
1 answer
233 views

The term for determining the pixels of a raster image

I am looking for an english well-established term for determining: 1) invalid/nodata raster image pixels (№ 1 - black ones on the image below) and 2) valid/data raster image pixels (№ 2 - other ones ...
Comrade Che's user avatar
  • 7,206
3 votes
1 answer
42 views

Terminology for "projection" on different 2d planes (no sphere involved)

I'm building software and want to use good terminology for variables, tables, etc. Most of my work involves blueprint drawings on which I render shapes (pins, polygons, etc). The same set of pins can ...
Michael's user avatar
  • 141
1 vote
1 answer
186 views

What does "faceting" mean in a geo/map context?

I saw some folks talking about "faceting" in relation to a map data display, what does this mean in general terms? Examples?
Harry Wood's user avatar
0 votes
1 answer
846 views

model builder expressions code block and definitions

I am having difficulty wrapping my brain around the point of the expression vs the code block. What am I suppose to be defining? I copied the example from calculate value in the ArcGIS help website ...
Damned_Novice's user avatar
2 votes
1 answer
210 views

In which coordinates (x, y, z) are vertical grids expressed?

When working with 2D maps, coordinates are always expressed in X and Y. Adding a 3rd dimension also adds the Z-coordinate, which typically stands for height. However, when working with vertical ...
MoekToe's user avatar
  • 143
2 votes
1 answer
102 views

Which projection conserves lengths?

I would like to crop rectangular fragments of given size and for these purposes I need coordinates, which covers all Earth and measured in meters. I wrote the following picture: Latitude and ...
Dims's user avatar
  • 571
16 votes
1 answer
15k views

Difference between bounding box, envelope, extent, bounds?

Every time when I create a script to manipulate vector (point, line and polygon) in python I meet this doubt. What is the difference between bounding box (bbox), envelope, extent, bounds?
Diogo Caribé's user avatar
8 votes
1 answer
143 views

What does "correctly noded" mean?

I've never seen this term, and I'm wondering what it means, with regard to ST_Polygonize NOTE: Input linework must be correctly noded for this function to work properly
Evan Carroll's user avatar
  • 7,081
1 vote
0 answers
124 views

What's the difference between classification/clustering and zoning?

A week ago I had an exam and there was a question: What are the main steps of zoning in a GIS? I didn't understand the question and asked the instructor what does she mean by zoning (in ...
Sepideh Abadpour's user avatar
9 votes
2 answers
2k views

Finding Similar Map Paths

I'm looking for an algorithm which, when given a particular route on a map with attributes such as incline/distance/shape/etc, can find a route which is similar (in terms of the attributes) but starts ...
Chris Foster's user avatar
3 votes
1 answer
548 views

What is seamless spatial information?

In the of the European INSPIRE directive the following "common principles" are presented: 1. Data should be collected only once and kept where it can be maintained most effectively. 2. It ...
ragnvald's user avatar
  • 3,191