For questions regarding the increments used in measuring values.

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42 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 = ...
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1answer
171 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 ...
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0answers
28 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 ...
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0answers
28 views

Hydrology Analysis via SAGA - what is the unit?

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 ...
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1answer
64 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 ...
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1answer
24 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.
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31 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 ...
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1answer
82 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 ...
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43 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 ...
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1answer
93 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 ...
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1answer
84 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 ...
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67 views

Surface Volume 3D Analyst tools

I'm using Surface Volume tool (ArcGIS 10.3) to calculate volume of air from a valley. I delimited my DEM (clip tool) and choose Below as plane reference with 603 m as height. The DEM is projected in ...
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1answer
553 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 ...
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1answer
73 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------------------------------------------------ ...
2
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1answer
74 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 ...
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0answers
54 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 ...
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1answer
181 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 ...
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1answer
43 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 ...
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1answer
144 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 ...
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1answer
396 views

Determining the slope of a DEM (SRTM-data) in QGIS

I'm new to QGIS and I have to calculate the slope of a DEM (I use srtm-data). I already detected the geoalgorithms toolbox and I also produced a raster layer with the slope using the tool "slope, ...
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2answers
163 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'. ...
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0answers
24 views

Setting correct units for Near tool?

I need to use the near tool to calculate distances between data points and a stretch of coastline. My problem is that when I run the function, the values that come up in the Field of the points' ...
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1answer
332 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 ...
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0answers
17 views

Adding a Z Unit [duplicate]

I'm struggling with the Z Unit conversion of some data. Both the NHD data and my DEM are in a GCS with Decimal Degrees. These data sets project perfectly on the fly, but after I adjust the Z Unit of ...
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1answer
218 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 ...
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0answers
98 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. ...
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0answers
162 views

Changing unit of area from unknown unit to square meters

I am using QGIS 1.8 and I have this polygon. I want to know the area of this polygon and I have used field calculator and it shows my area as 651692439. Under the general tab, CRS is EPSG:4326 - WGS ...
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2answers
2k 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 ...
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1answer
1k 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. ...
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2answers
1k 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
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1answer
330 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 ...
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1answer
389 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 ...
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2answers
783 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 ...
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0answers
1k views

Convert a decimal degree to meters from the MySQL Spatial GLength

The MySQL Spatial function GLength returns the distance between two points, this distance is in the same unit from the projection. Since I'm using the WGS84 (SRID:4326) the answer will be with ...
2
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1answer
149 views

Label size in map units, geoserver .sld file

Is it possible to define labels in map units in a sld file? Thanks.
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2answers
4k 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 ...
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0answers
701 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
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1answer
294 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 ...
2
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1answer
922 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 ...
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2answers
2k 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 ...
2
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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 ...
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5answers
4k 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 ...
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0answers
64 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 ...
4
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1answer
512 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 ...
0
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0answers
33 views

Set buffer radius in metric units in qGIS [duplicate]

Possible Duplicate: What is up with QGIS buffer tool units? A similar question to this one has already been asked QGIS - Change unit of measure from degrees to meters, but none of the steps ...
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1answer
7k 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 ...
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0answers
760 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 ...
4
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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 ...