Questions tagged [noise]

May refer to ambient sound or random/uncorrelated patterns of samples in data, particularly raster data.

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0answers
55 views

Speckle on LiDAR data

Does LiDAR data suffer from the speckle noise like the SAR images and ultrasound cardiac images I'm used to? I think speckle noise is inherent to all active sensors, but I'm not sure for LiDAR ...
5
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1answer
148 views

Fixing spikes in DSM from LiDAR?

I have a DSM derived from drone LiDAR that I want to use as a base to drape imagery and, paired with a DTM, as a basis for estimating canopy height/volume. Unfortunately, the DSM has has many "spikes"...
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8answers
3k views

Editing LiDAR point cloud to remove noise/outliers present below and above ground?

I have "dirty" LiDAR data containing first and last returns and also inevitably errors under and over the surface level. (screenshot) I have SAGA, QGIS, ESRI and FME at hand, but no real method. What ...
3
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1answer
94 views

Slope raster seems to come out distorted?

I've been trying to get a slope raster from a DEM, so I can reclassify it and aggregate it with land use data. The problem is that my slope raster seems to have a lot of distortion (diagonal lines). ...
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1answer
97 views

Cleaning up polygon generated from NDVI raster

So I have NDVI raster files for about 1000 acres of vineyards we manage. What I have done is created a model that takes the NDVi raster, reclassifies it to isolate out the areas of high vigor, then ...
2
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1answer
76 views

Gap filling for linear features using ArcGIS Desktop?

I have a Landsat time series from which I derived NBR using bands 4 and 7, and delta NBR (to show changes). I then set a threshold based on the mean and standard deviation delta NBR values to ...
3
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2answers
729 views

How to create a sound map using ArcGIS?

I have locations of the points which produce sound. I want to create a sound map based of those points, topography, and the distance at which a sound can travel. On this picture you can see the red ...
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0answers
27 views

Eliminate noise when using spatial join with tolerance

I have two networks, which doesn't align perfectly with each other, so when I want to attach attributes from one to another, I have to use spatial join with a certain amount of tolerance. However, at ...
9
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6answers
5k views

Detecting and fixing outliers in a GPS trajectory

I need to find an algorithm or method that can detect outlier latitude longitude points in a trajectory during post-processing, which can then be fixed (brought back into the trajectory's path based ...
2
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2answers
2k views

A method for noise reduction in GPS derived cycling routes

I'm pre-processing GPS data to assess possible methods for a planned research. The aim of the research is to use crowd-sourced cycling routes data to plan a cycling paths in an Israeli city. ...
1
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0answers
68 views

Managing or Reducing noise in a mosaic raster

I have created a raster with the Mosaic to New Raster tool from 3 separate rasters. However in my mosaic I have some consecutive pixels which seem to be the noise of the previous procedure. Is there ...
1
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0answers
84 views

Is it right to remove salt & pepper effect from a product produced by clean images?

I have two images from classification (different years) and I want to find the changes of land cover . I have cleaned the two images (salt and pepper). When I create a cross product of the category ...
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3answers
275 views

Computing population exposure

I am new to ArcMap. I have polygon layer, which represents buildings, and each polygon has number of inhabitants in Attribute table. Then, i have a layer which shows noise levels in the area, ...
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2answers
7k views

Using raster to clip vector data

I have high res raster data covering 2million km sq, with a field where each cell has a value from 0 to 100. I need to create a "mask" using the cells with a value over 12 in that field. I then need ...
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2answers
506 views

How to find a route given a set of noisy points

First of all, I'm a total noob to GIS problems. Let's say I have a set of noisy GPS points (tracked while driving) along a number of streets. Is there a way to get the most likely route that generated ...
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3answers
2k views

Which interpolation method for noise mapping?

I want to create a noise map with measured point data. But I want to have a planar representation, so I need an interpolation method. Which one is the 'best' for measured noise data? I prefer 'IDW'...
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5answers
7k views

Fix Landsat 7 SLC-off in ENVI?

I have a couple of Landsat 7 images and they all have striping as a result of the SLC failure. Does anyone have any suggestions as to how to destripe the image using ENVI? I plan to use these images ...
5
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1answer
3k views

How to perform Noise Pollution Mapping using ArcGIS for Desktop?

I've been trying to do a noise pollution map, and I really don't know where to start with the information I have. The end result needs to be like in the link below. I've seen the question, Creating ...
3
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1answer
799 views

Masking/removing polygons from shapefile

I have a shapefile containing the road traffic noise of a city. The shapefile has 5 columns, where 'noise_in' (noise interval) ranging from 1-5 is included. I want to remove/mask the road noise from ...
9
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2answers
10k views

Creating noise maps using ArcGIS for Desktop or Open Source Desktop GIS? [closed]

In a previous role I helped create Noise Maps for Northern England. The predicted noise levels was done using the IMMI package (which I can recommend) and the cartographic output was done in ArcMap. ...
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1answer
987 views

Why is the imported TIFF file distorted with noise in Quantum-GIS?

I've a TIFF-file. Loading the raster image into QGIS does not display correctly. (Using the Add raster layer button.) It seems to be distorted with noise. See image below: The source of the TIFF file ...
4
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1answer
904 views

Disable sounds/beeps in QGIS?

Is there any way to disable, mute, or otherwise change the incessant message 'beep' in QGIS? I need volume on the PC for other unrelated notiifications yet am tired of apologising for the echoing ...
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3answers
246 views

Terrain Beautification

The satellite imagery i am rendering is not realistic does not look good. So i was planning to improve things through code(like adding noise to data or using different overlay texture for different ...
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2answers
1k views

Adding noise to a raster

I want to add some fine-grained noise to a raster in an automated python process (i.e. I do not want to use Photoshop or GIMP). I looked at PIL, but unless I'm mistaken, it doesn't seem to have any ...