For questions regarding the increments used in measuring values.

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11
votes
1answer
10k views

Understanding QGIS buffer tool units?

I have been trying to figure this out for a couple weeks now and have had no luck getting the buffer tool to accept anything but degrees as units of measure. I have found lots of stuff saying the ...
8
votes
2answers
3k views

DEM Elevation Units

I'm fairly new to the GIS world, and have a quick question. I'm currently using 10.1. I do not know much about rasters, so does transforming a DEM from one projection to another automatically convert ...
8
votes
5answers
5k views

Calculate distance in km to nearest points (given in lat/long) using ArcGIS DEsktop and/or R?

I have two point datasets in ArcGIS, both of which are given in WGS84 lat/lon co-ordinates and the points are spread across the whole world. I would like to find the nearest point in Dataset A to each ...
7
votes
2answers
3k views

What's the Workflow for buffering in meters/km using WGS84 layers?

I'm a little bit new to GIS, so bear with me a minute.... I'm using QGIS 1.7.4-Wroclaw and working with an SHP layer in WGS84. I want to buffer out to a certain number of kilometers from this layer ...
7
votes
1answer
237 views

What is the size of a “point” unit in Esri software?

When creating point symbology with Esri software, we can use points, in, cm, or mm as a unit of measurement. Due to the fact that there are a few definitions of a "pt" or point, which of the ...
6
votes
2answers
699 views

How do I set the composer layout units to inches?

I open an new composer and select ANSI A for my paper. The notation after the name is "Letter; 8.5inx11in", but the width and height are displayed in mm, and the units selection is grayed out, so I ...
5
votes
2answers
1k views

Custom scalebar units in ArcMap?

Is it possible to create a scalebar in ArcMap that shows distances in custom units? I understand how to do this manually, but it would be great if I could define a custom unit of measurement (let's ...
5
votes
1answer
99 views

Which system of units does the unit 'degree' belong to?

Let us say that I would like to store latitudes and longitudes like this: lat 35 degree long 80 degree Which system of units does the unit 'degree' belong to? It is not really a SI unit nor a ...
4
votes
2answers
2k views

What is the unit the shapely length attribute?

I'm doing a very simple calculation of the length of a polyline using shapely: from shapely.geometry import LineString ... xy_list = [map(float,e) for e in xy_intm] line = LineString(xy_list) s = ...
4
votes
1answer
156 views

Create Features Using Feet Temporarily

I do a lot of parcel editing and have it in a topology set to a UTM coordinate system. 99% of all survey plans I add into the parcel fabric are using metres as there unit. That 1% of the time I get a ...
4
votes
1answer
540 views

How to specify coordinate reference system (CRS) for scalebar that is different to project CRS?

Is it possible to specify a coordinate reference system (CRS) for the scalebar that is different to the project CRS? For example, my project CRS uses geographic coordinates (lat/long), the reason ...
4
votes
1answer
1k views

Dimensional analysis/conversion problem: Map scale to image resolution (dpi)

Given a map scale of 1:17,200 and a raster whose cell size is 6 inches, what resolution (dots per inch) should I choose when exporting the map to an image in order to maintain the raster's native ...
3
votes
1answer
590 views

How can units be defined in QGIS for the Rasterize tool?

I am using QGIS 2.4 (Chugiak) via the kyngchaos build for OS-X. My question is--when using the Rasterize tool to convert a point vector layer to a raster and using the "Raster resolution in map units ...
3
votes
2answers
2k views

How do I know the vertical/horizontal units of my DEM? I'm creating a slope using gdaldem

I'm using gdaldem to create a slope map. I can apply a scale. The default is 1. The notes say: Ratio of vertical units to horizontal. If horizontal unit of source DEM is degrees (e.g WGS84 ...
3
votes
2answers
7k views

What are the units of the calculated area from a raster in decimal degree

I'm trying to calculate area for a raster file which contains 2 layers (0 for unsuitable habitat and 1 for suitable). It's been calculated successfully but I don't know what is the unit of the ...
2
votes
1answer
1k views

What coordinates are expressed in 6-7 digits numbers?

I am processing XML documents containing geographic information, and even though they are coming from the same source they are using different coordinates units. The first one is a regular ...
2
votes
1answer
116 views

Converting geographic units with ArcPy

I am trying to compare a set of point features to the centroid of a single feature polygon using ArcPy. The problem is that the polygon generates a set of XY coordinates in meters, whereas the set of ...
2
votes
1answer
172 views

Label size in map units, geoserver .sld file

Is it possible to define labels in map units in a sld file? Thanks.
2
votes
1answer
2k views

How to get $length in meters in QGIS?

I read a lot of posts concerning that subject, nevertheless I cannot solve to problem of getting $length in the field calculator in meters rather than in decimal degress in QGIS. The CRS of original ...
2
votes
1answer
66 views

How to define measurement units in grass

I need to get the length and area of some landscape features in the US. My data was in lat and long degrees. I created a new location with an UTM projection and read the data into grass. Now if I ...
2
votes
2answers
195 views

How to calculate area of shapefile with a merged layer

so i have 'save as''d the new project and layer with my new Custom CRS project string being '+proj=laea +lat_0=70 +lon_0=0 +x_0=0 +y_0=0 +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +units=m +no_defs'. ...
2
votes
1answer
623 views

Unable to change the layer unit in QGIS

I have been working with QGIS for 2 weeks and I got the hang of it now. The problem now is I cannot calculate the area of a created polygon. Because the layer unit is not changing to meters. When ...
2
votes
1answer
2k views

How to read the area column in QGIS?

I have few problems understanding how units are managed in QGIS. According to the area column I created for a shapefile, the area of a shape is 0.7727... I just checked on Wikipedia and indeed the ...
1
vote
3answers
106 views

Area units for output polygon in WGS 84 UTM Zone 32N using QGIS

I am calculating the area of my polygon and I have used WGS 84 UTM zone 32N to calculate the area (using geometry on the field calculator) of my polygon, and I obtained 745461 (without units). How ...
1
vote
1answer
2k views

Pseudo-Mercator projection with Decimal Degrees?

Hope this isn't a duplicate, did some searching but none seemed quite the same. Projection I want: WGS84/Pseudo-mercator. Selected. Looks Great. Canvas units I want: Decimal Degress. Selected. ...
1
vote
1answer
23 views

Measure length in specific units like 'aln' arcmap

I have an old map in aln, 1 aln=0.5934 meters. I would like to draw lines using directly this measure unit without having to convert in meters each time to draw the lines. Is there any way to ...
1
vote
1answer
149 views

Set GPLinearUnit type parameter default based on input spatial reference (Buffer Example)

Within a .pyt python toolbox I'd like to have a parameter of data type GPLinearUnit get a default value based on an input Feature Class (FC). The standard Buffer (Analysis) tool works as a great ...
1
vote
1answer
103 views

In a GeoTiff, what unit are extents in?

I was looking at the GDAL metadata of a USGS GeoTiff quad (o48118e8) with the GdalToTilesWin program. It dumped the following info: Name o48118e8.tif Size X/Y 5315/6780 ResolutionX/Y 2.4384/2.4384 ...
1
vote
2answers
53 views

Is there an equivalent to Map unit in ArcMap?

I need to have points, lines and texts in ArcMap in map units like in QGIS so I can zoom to the feature and see it like it's a raster. Is there anything I can do to manage that? I use ArcMap 10.2.2 ...
1
vote
1answer
937 views

Conversion between semicircles and latitude units

I've recently come across the semicircle unit that is used to describe a latitude and longitude using the maximum precision allowed by a 32-bit number. The conversion here is given as degrees = ...
1
vote
1answer
154 views

How do I read and modify heat map value classification on QGIS?

I am trying to create a heat map on human encroachment using the heatmap plugin of QGIS 2.2. I have no problems creating a good looking raster file using a 2 km radius but I can't find my way around ...
1
vote
1answer
376 views

Adjusting Z Units on a DEM

I am learning how to use ArcHydro and attempting to change the Z Units because I get a warning message saying the Spatial Reference Doesn't Match. The DEM was in Meters, and I adjusted the Z Unit to ...
1
vote
1answer
396 views

Which horizontal unit is used on the table of the Profile Tool?

Does anyone knows what horizontal unit is used on the table of the "Profile Tool". Vertical is in meter but I don't know about the horizontal axis. Knowing the length of my profile, I tried to divide ...
1
vote
0answers
29 views

Same CRS but different units of raster cells in qgis

I have two rasters with the same CRS (WGS 84/UTM 34N). One is from a LiDAR scan and the other raster is created thru interpolation of point measurements by me. I would like to change the cell size to ...
1
vote
0answers
35 views

QGIS Units and Scale

I am exploring QGIS 2.10.1-Pisa for the first time. I'm familiar with ArcMap, but I need to explore QGIS as an alternative. I am having a hard time trying to figure out the units and scale situation. ...
1
vote
0answers
38 views

Z factor to get the results in square meters and cubic meters?

I have a DEM surface in WGS 1984.I want to calculate surface area and volume in different elevations.I wonder for example If I want to measure the area and volume below some height how shall I set the ...
1
vote
0answers
43 views

Hydrology Analysis via SAGA - what is the unit? [closed]

I did a couple of analysis via SAGA about an area in Iceland...I've never worked with SAGA before, could anyone tell me what Units the numbers in the legends for "Catchment Area Recursive" and ...
1
vote
1answer
38 views

How to do unit conversion on a Terrain dataset?

I was wondering if there is a way to change the elevation units of a Terrain dataset (from example from meter to feet). Any idea/guidance is much appreciated.
1
vote
0answers
40 views

How do you change the map units returned on ArcGISRuntime 10.2.4 for .NET

I am working on a project that requires the frequent usage of feet as the expected unit of input and output. We're using the .NET SDK with the Esri.ArcGISRuntime.Controls.Mapview in WPF. Basically we ...
1
vote
0answers
91 views

Trouble interpreting zonal statistics as table output

Consider this a follow-up to this question. I transformed a census block group vector map (decided to use this instead of census tracts) into a raster map and generated a kernel density map using ...
1
vote
0answers
83 views

AutoCAD dimensions units

Not sure if this question belongs (Please tell me if it isn't) I have an AutoCAD drawing that is in centimeters, and every time I insert a dimension, it appears in centimeters (which makes sense ...
1
vote
0answers
120 views

How can I obtain the unit of a projection SRID?

Given a projection SRID, is there a way I can obtain the coordinates unit string (meter, degree, ...) ? In PostGIS for example, it looks like it is present in the srtext column of spatial_ref_sys. ...
1
vote
0answers
830 views

Distance Matrix in QGIS

Can anyone help me with the distance matrix tool in QGIS? Is there a tutorial about it? It sometimes crashes when I use it and the values that it produces seem strange. I am a beginner in QGIS, so I ...
1
vote
0answers
66 views

QGIS scalebar shows a wrong scale [duplicate]

Possible Duplicate: Why does QGIS scalebar show a wrong scale? I want the scale-bar in QGIS to be in meters/kilometers. Usually it's in degrees, but if I change it to meters it is displayed ...
1
vote
0answers
878 views

mixing lon/lat and mercator layers in a MapServer .map file

I have a basic question about my MapServer .map file, which has two layers, each with a different coordinate system, longlat vs. mercator. See my .map file below. If I leave it as shown below, with ...
0
votes
1answer
141 views

How to change the Map Units in Grass?

because v.segment measures all offsets in map units, i have to change it. (I want to put all of 50 meters a point) So I checked g.proj -p: -PROJ_UNITS------------------------------------------------ ...
0
votes
1answer
466 views

creating circle with radius in metres

I am using shapely and python. How should I go about creating a circle using shapely whose radius is in meters? If i use sampleCircle = Point(1,1).buffer(1) print sampleCircle.area This returns an ...
0
votes
0answers
11 views

Guideline on how to reference units and intervals in the legend

I often use some kind of elevation data in my maps in form of grids and contours. I never really put much attention to how to properly specify units and intervals in the legend but now polishing my ...
0
votes
0answers
12 views

How to translate units to pixels for symbology rendering in Mapnik?

I would like to translate .QML-file to Mapnik .XML to render layer via Mapnik using the same style that is created for QGIS. The problem is that sizes and offsets on QGIS are defined in millimeters or ...
0
votes
0answers
51 views

Setting units for arcpy fishnet tool, given unprojected input

I'm trying to use arcpy to create a grid over each of a large number of metropolitan areas across the US. I'm iterating over each metro and trying to create a grid over each one using the "fishnet" ...