Questions tagged [terminology]

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

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10
votes
1answer
5k views

Raster vs Grid vs Lattice terminology?

I have a question about GIS terminology - what is the difference between grid and raster and grid and lattice - in theory?? I thought, that raster is regular network and value is in the cell and the ...
1
vote
1answer
48 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 ...
8
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7answers
2k views

Best definition for GIS today? [closed]

What is the best definition of Geographical Information Systems? Has the definition changed at all since I was taught it 10yrs back? The technology has changed a lot and it is more powerful than it ...
0
votes
1answer
34 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 ...
12
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4answers
15k views

Spatial data? Geodata? Geographic Data? Geospatial data? [closed]

Language changes all the time and I see various uses of the words defining the data we use in GIS in our day-to-day lives. But what's right? Is there a right answer out there that we would all agree ...
1
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1answer
88 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?
4
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1answer
3k views

Difference between 'join' and 'merge'?

Suppose one wants to make polygons A and B, and their respective attributes to be one unique polygon C. What is this GIS operation called? Is there any difference in GIS terminology about "joining" ...
2
votes
2answers
112 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 ...
0
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0answers
69 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, ...
2
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2answers
4k views

What's the difference between “route” and “track” in OruxMaps?

What's the difference between "route" and "track" in terms of navigation? Is there a conceptual difference or only a technical one? For example OruxMaps treats the two terms differently: (source)
100
votes
6answers
154k views

Differences between DEM, DSM and DTM?

I am listing some of the acronyms used in our work and had to stop to think about whether to list these together or separately: DEM: Digital Elevation Model DSM: Digital Surface Model DTM: Digital ...
3
votes
1answer
82 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 ...
228
votes
11answers
120k views

Difference between projection and datum?

What's the difference between a projection and a datum?
4
votes
1answer
130 views

What is the standard terminology for raster alignment?

I would like to identify two types of raster alignment (assuming SRS is the same), but I am unsure of the correct terminology for these (or whether there is even a 'standard')? First, there is 'pixel ...
1
vote
1answer
181 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?
2
votes
2answers
132 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 ...
2
votes
1answer
47 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?
2
votes
1answer
177 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 ...
1
vote
1answer
52 views

Defining Lands that are not deserts [closed]

I need to know what we call the lands that are not pure deserts that i can think that they are the areas of metropolitan areas plus rular areas or forests plus areas that are near freshwater that can ...
9
votes
3answers
192 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 ...
10
votes
1answer
535 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?
6
votes
1answer
382 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
3
votes
1answer
2k views

What is the 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 ...
2
votes
1answer
509 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)...
9
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2answers
1k 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 ...
4
votes
1answer
54 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 ...
2
votes
2answers
2k 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. ...
0
votes
1answer
307 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 ...
3
votes
1answer
69 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 ...
3
votes
1answer
34 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 ...
0
votes
1answer
248 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 ...
15
votes
4answers
552 views

When did the word “geospatial” first come into usage?

For historical reasons, I'm trying to figure out when the term "geospatial" came into use? The earliest usages I can find are from around 1994, but I would be really surprised if it wasn't used ...
13
votes
4answers
24k views

What is layer file (*.lyr) in ArcGIS Desktop?

My organization uses *.lyr files consistently as a means for our users to view the data and build their mxds. It works great for our purposes, but we have run into an issue where we don't think the ...
4
votes
2answers
263 views

“Official” definition to hyperspectral sensor

I was checking in the literature about a formal definition for hyperspectral sensors, and the most complete definition I found was from The Center of Space Research (@ University of Texas in Austin): ...
2
votes
1answer
76 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 ...
2
votes
1answer
69 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 ...
8
votes
1answer
5k 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?
4
votes
2answers
360 views

Is there a source for common GIS terminology in French?

I am trying to find a a resource that provides English/French translations for GIS terminology. Obviously I could use Google or a French/English dictionary, but there are many cases where there are ...
7
votes
1answer
84 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
1
vote
0answers
99 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 ...
3
votes
1answer
167 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 ...
5
votes
2answers
4k views

Which one is called inset map in this?

I am confused as to which one is technically the inset figure in the below map. I know an inset map is one which has more detail. But in this case which one is referred to as an inset map ...
2
votes
2answers
62 views

What does n-D stand for in the following operator definitions?

PostGIS shows a listing of operators that make reference to n-D &&& — Returns TRUE if A's n-D bounding box intersects B's n-D bounding box. &&&(gidx,geometry) — Returns TRUE ...
6
votes
2answers
932 views

How do MODIS products naming conventions work?

If I have the product MOD13Q1.A2014001, does it represent the previous 16 or the 16 days after January 1st? I.e., the product is made with 16 days, but how to determine if it was taken the previous ...
9
votes
1answer
156 views

Is there a name for a situation when the place is clearly or unclearly named?

This is not specific to any system. Suppose there's a large red rock on a terrain which can be easily found and clearly seen and there's an artificial object such as a mall near that large red rock. ...
2
votes
2answers
102 views

Describing input field in ArcMap Field Calculator window?

A few days ago I was answering Comparing two fields and printing result as 1 (if number matches) or 0 (if not) using Python Parser of ArcGIS Field Calculator? When describing the process required ...
0
votes
2answers
42 views

Describing geographic characteristics by lat/long?

I'm not sure of the right terminology to use to google for a database of information. The data in the database should list geographic characteristics of an arbitrary lat/long. Stuff like height ...
12
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2answers
13k views

What are LiDAR returns?

Can someone help with an explanation and some references, in order to understand the nature of return pulses within a LiDAR system.
3
votes
1answer
45 views

Terminology for groupings/categories within ArcGIS Pro galleries?

In ArcGIS Pro 1.1.1, when I use the INSERT tab to insert a New Layout, I am offered a gallery of layout templates to choose from. I think the terminology that I have used so far matches that found in ...
2
votes
0answers
44 views

What's the usual term for “ground plan based” [closed]

I don't know if "ground plan based" is the right word in the following context: A computer program reads a ground plan and produces a result ground plan. The result groundplan's deviation from the ...