The degree of closeness of measurements of a quantity to that quantity's actual value

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6
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1answer
1k views

Cheapest centimeter accurate satellite positioning (GNSS/GPS)

I am looking for a cheapest possible GNSS/GPS setup with a centimeter precision without much HW hacking. I am not able to produce my PCB or do any soldering (though I would do that if there is no ...
1
vote
1answer
94 views

What sub-meter geolocation solutions exist and how can I integrate them into a web and mobile mapping workflow?

I am the manager of seven water systems. What I am trying to do is map out every meter and valve on to a map and then my workers can have the maps on their iPhones so when they have to go fix a water ...
0
votes
1answer
42 views

Benefit of DGPS for relative accuracy and speed measurements for receivers close-by each other

Consider that we are interested only in the speed and relative position accuracy of GPS receivers (i.e. their absolute try position on earth is NOT important). These receivers are all in a 90m x 90m ...
5
votes
0answers
153 views

How to compare two sets of points in QGIS?

I have two point layers with XYZ data; one set are points measured in the field and the second set is a Lidar data set. I want to check the accuracy of the Lidar in comparison to the measured data. ...
5
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0answers
310 views

How to store Large Raster Images of Equipotential Surface Generation Using Monte Carlo Simulation?

I have a large (1GB+) raster that I am using as the base for the generation of an equipotential surface. This is to assess the accuracy of DEMs derived from another source. In situ observation is ...
2
votes
0answers
34 views

How to measure RTK accuracy of a moving vehicle?

I am currently working with tractors using a RTK enhanced automated steering system. One of the biggest problems is that even RTK can have a inaccuracy of 2cm. This can be too much for some possible ...
1
vote
0answers
105 views

Collector for ArcGIS PDOP and GPS collection configuration settings

My company just acquired a Geneq SXBlue II GPS receiver to pair with an iPad and the Collector for ArcGIS app. The functionality is awesome and loved by everyone, but since we have biologists on our ...
1
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0answers
37 views

How to select random objects in eCognition?

I classified a Landsat image in eCognition and now I want to select random objects so that I can compare their class to ground-truth data and perform the accuracy assessment. How can I do this in ...
1
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0answers
1k views

Translating hdop, pdop and vdop to metric accuracy from given NMEA strings

How can I translate dilution of precision to a metric unit? For example: say I got 1.2 in hdop from NMEA sentence of my GPS receiver, in what should I multiply to get a metric accuracy? Just like the ...
1
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0answers
46 views

Question about projected coordinate systems 30m DEM for Contiguous US

What is the best Projected Coordinate System (PCS) for the contiguous US (whole, not parts) if I want to maintain distance and area accuracy as much as possible across a nationwide DEM dataset? I'm ...
0
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0answers
30 views

ODK Collect GPS Accuracy

Good day. Is it possible to require a minimum accuracy of the GPS widget? I know about accuracy threshold but what I need is to prevent forward swiping/finalization of the form if GPS accuracy is low. ...
0
votes
0answers
43 views

How to randomly generate 3 X 3 pixel window/grid size in ArcMap?

I have a raster image in ArcMap and I want to assess the accuracy of my raster image with a reference image. So, I need to randomly generate a bunch of (i.e 50) 3 X 3 pixel window/grid size from my ...
0
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0answers
26 views

Objective comparison of different land cover data sets

One of the answers in this question Equivalent of CORINE land cover data sets for rest of world mentions the difficulty of comparing different land cover data sets such as CORINE and Global Land ...
0
votes
0answers
73 views

ERDAS file not recognized as ERDAS Hierarchal File Architecture (EFHA)?

I am trying to do an accuracy assessment in Erdas using "user defined ground control points" (I collected the GPS points myselfin the field using a handheld GPS). However, when I load the thematic ...