Questions tagged [change-detection]
Change detection is the process of identifying changes in map content over time.
100
questions
0
votes
0
answers
22
views
How can I differentiate between water body and snow on my Landsat images using ArcGIS?
I am trying to detect changes in water bodies over a couple of decades. but when I use NDWI to calculate water it includes snow in that range as well, I can't differentiate between these two. I even ...
- 1
0
votes
0
answers
53
views
Change detection in ArcMap
I tried to do change detection using ArcMap. To do this I followed the following steps.
Convert from raster to polygon via "value" field (aware as I have 7 classes)
Dissolve through ...
0
votes
1
answer
55
views
How to export this change map
I am trying to get this change map downloaded for just California, but no matter what I try, it just downloads empty datasets that look like lines. It's always the same size no matter what I change in ...
0
votes
1
answer
76
views
GEE: arraySlice to find first, second, third, etc. entries in image array
I'm working off of a great tutorial on continuous change detection from this book chapter. I use the tutorial data and code to demonstrate the issue I'm encountering.
Using a stored array image, we ...
- 315
0
votes
0
answers
201
views
Conducting change detection analysis on classified land cover classes in ArcGIS Pro
I have a feature class shapefile consisting of many mangrove polygons and one non-mangrove polygon for my study area. A screenshot of my attribute table shows I have classed mangroves as 1 and non-...
- 1
0
votes
1
answer
383
views
Change detection for raster layers
I'm working with multiple raster layers representing LULC data, Corine maps, from various years. My goal is to identify the pixels that have undergone change and determine the specific transitions ...
- 117
0
votes
1
answer
390
views
Detecting Land Use Land Cover Changes from Copernicus Corine Maps in GEE - Calculating Areas of LULC Change Pairs
I'm trying to detect land use land cover (LULC) changes between 1990 and 2000 using the Copernicus Corine land cover maps in Google Earth Engine (GEE). However, I'm unable to find change maps in the ...
- 117
0
votes
1
answer
29
views
Get output from this code
I get this error
Error: Image. select: Pattern 'scale' did not match any bands. (Error code: 3)
from this code.
Map.centerObject(table);
Map.addLayer(table);
var before = ee.ImageCollection('...
- 9
2
votes
0
answers
50
views
How can we know that a random satellite image is atmospherically corrected or not using python?
If a satellite image in .tiff format was given. what are the values that can be obtained from a satellite image using python to see whether it has atmospheric errors or not?
I am expecting what values ...
1
vote
1
answer
942
views
Land cover change detection using raster calculator in QGIS
I am trying to find the difference between land cover data from two years. I have used the same classification for both the raster files. For eg:
1-Agriculture
2-Forest
3-Urban
4-Water bodies
5-Barren ...
- 13
0
votes
1
answer
629
views
Understanding 'ccdc' algorithm in Google Earth Engine
I want to know how the 'ccdc' algorithm, which is deployed on GEE, detects changes.
Does the algorithm use the method on the left, the method on the right, or some other method?
---the picture came ...
- 27
0
votes
2
answers
763
views
Subtracting two Feature Collections in Google Earth Engine
I have two feature collections (before and after) that I want to subtract in Earth Engine. Each Feature Collection has an NDVI band computed, BF_NDVI for the before Image and AF_NDVI for the after ...
- 312
0
votes
0
answers
735
views
When using Landsat and Sentinel-2 data to implement the change detection, I got very different result
I used the code that is from gee-ccdc-tools.Now I know the actual time of change. I just change "getLandsat" to "getS2" for the change detection.And the result of change detection ...
- 27
1
vote
1
answer
460
views
Shoreline change analysis in ArcGIS Pro
I am trying to determine the change/reduction of shorelines using Sentinel 2 data using ArcGIS Pro 2.8. However, I don't have a lot of experience in raster analysis and I'm a bit at a loss... how ...
- 1,205
0
votes
0
answers
152
views
Comparing shoreline pixels across Sentinel data with Google Earth Engine
I am trying to determine the change/reduction of shorelines using Sentinel 2 data. I thought it would require heavy processing power and was thus leaning towards using Google Earth Engine for the ...
- 1,205
0
votes
0
answers
378
views
Using ArcGIS Pro to measure change in land use over time (dynamically evolving maps)
How can I use ArcGIS Pro to record change in land use over time?
I am working with this landuse dataset for London. I would like to know what use any given polygon was being put to each year between ...
- 1
0
votes
1
answer
456
views
Change Detection Chart from lists in Google Earth Engine
I want to create a chart from classes area (square kilometers) that I calculated from the land cover supervised classification process. These classes area are in form of lists (these are printed in ...
- 31
3
votes
1
answer
109
views
Analysing differences between 2 dataset versions [closed]
In my GIS department, we purchase vector GIS data and regular updates. Each update delivery includes a new "snapshot" of the dataset, which is a brand new version of the entire dataset. As ...
- 10.2k
0
votes
0
answers
137
views
How to determine temporal land cover change using two rasters? (From-to)
ArcMap. I am having trouble finding the correct method.
I want to end up with what is essentially a confusion matrix showing what each class from the before image converted to in the after image. I am ...
- 23
1
vote
0
answers
61
views
Need assistance in project regarding Change Detection
My task initially was to classify the area into land-use classes like forest, sparse vegetation, agriculture, river, etc
I had done that by clustering the whole area and then reclassing it.
I had to ...
0
votes
1
answer
1k
views
How to perform change detection using classified land cover map in Google Earth Engine? [closed]
I have generated land cover maps of three different seasons using sentinel-2 data.
How can I generate a image that shows the changes of a land cover type between two classification results?
What I ...
0
votes
1
answer
309
views
Calculating LULC change 1973-2014 of a classified map (raster converted to shapefile) in ArcGIS 10.6
I am attempting to workout landcover change between two classified landcover maps. Ideally I want to show percentage change between the years per landcover type. I think I have done this but I am ...
- 17
1
vote
1
answer
454
views
Combining multiple raster layers to make landcover map for Borneo
I am currently making a landcover change map for a Kinabatangan, Sabah, Borneo for my undergrad dissertation. I downloaded landsat MSS and 8 images. These were pre-processed and both classified using ...
- 17
1
vote
1
answer
962
views
Visualizing specific class from unsupervised classification in Earth Engine
I have classified an image into 20 classes using unsupervised classification for a specific region in Google Earth Engine. I want to check a specific class (say class 9) and visualize only that ...
1
vote
1
answer
128
views
How to identify landuse change with Sentinel data - specifically grassland/woodland to arable cropland changes
I have an assignment to assess whether it is viable to use sentinel data to monitor illegal changes of landuse from Grassland/Woodland to arable cropland.
This is the first time my environmental ...
- 10.2k
1
vote
1
answer
79
views
Comparing between two polygon class values
I have one polygon shapefile with two fields that I would like to detect their difference.
the fields have the same class values: between 0-4:
This is the first layer:
and this is the second:
I ...
- 2,207
1
vote
1
answer
262
views
Subtract two pixels-only- layers using rectangle extent
I have code in GEE that:
calculates the NDVI in a given polygon, from 2000 (based on Landsat 7) and 2019 (Landsat 8)
creates for each one a layer with pixels that their NDVI value is higher than 0.3
...
- 2,207
2
votes
1
answer
2k
views
Perform change detection using LandTrendr in Google Earth Engine?
I am having very basic skills in LandTrendr. I want to make a map showing year of detection and another magnitude of change, but I keep getting errors. I suspect the problem to be with the image ...
- 43
0
votes
1
answer
278
views
Classifying type of crop on satellite images using Python [closed]
I'm trying to make a classification on the send with python, but logically I find all the vegetation that I don't care about. The even more serious fact is that if the species is not present in a ...
- 443
1
vote
1
answer
84
views
Change detection between two binary images
Is there a scientifically-valid to use raster calculator to subtract two binary images (0, 1) to get the difference between Pre- and Post flood events?
In pseudo-code:
Difference "change detection" ...
- 31
1
vote
0
answers
1k
views
Doing change detection of land cover between 2 landsat images in google earth engine?
I am doing land use/ land cover classification of 2000 and 2018 year . I had completed supervised classification now i wanted to do change detection analysis. Please guide me how to do change ...
- 21
4
votes
3
answers
797
views
Bare Soil Detection
I try to find bare soil areas. Those which are bare over the whole year and those which are fresh harvest and remain bare over a certain time. I try to do this with sentinel-2 data. But the Problem is ...
- 471
0
votes
0
answers
247
views
Matrix union in ArcGIS
How can I do matrix processing in ArcGIS or ERDAS Imagine?
l have two different raster images for change detection. Matrix join same code filed information.
In this video link already done matrix in ...
- 1
0
votes
0
answers
221
views
Change detection using DEMs of difference and error quantification
Im currently working on a project in one of my seminars at university ("Advanced methods in natural hazard research").
We are modelling DEMs with Agisoft Photoscan using pictures from flume ...
- 1
0
votes
1
answer
447
views
Finding difference between two rasters using ArcGIS Spatial Analyst?
I know how to find difference between two rasters with Spatial Analyst tools, but how to display attributes, for example differences between two Corine Land (2006 - 2012) rasters, how to see codes of ...
1
vote
1
answer
368
views
Estimating building and vegetation volume with unclassified LiDAR datasets?
I'm trying to determine the ratio of building to vegetation change (i.e. how has the volume of built structures changed in proportion to the volume of vegetation) in a city over a period of five years....
- 11
1
vote
1
answer
440
views
Do I need to do Radiometric Normalization for time series analysis, if I'm using L2_Landsat8_SR data?
I'm doing some forest change detection across several years using L2_Landsat8 Surface Reflectance data. And I am implementing the method available in R (landsat::relnorm) for relative radiometric ...
- 35
1
vote
1
answer
1k
views
Calculate difference of subsequent images in a collection
how do I call a Specific Image inside a Collection, to loop over it?
this is for calculating the difference of images for each set of two subsequent images in a collection
dImage= Image(t=i+1)-Image(...
- 778
2
votes
1
answer
922
views
Comparing current image in collection to previous image in collection using Google Earth Engine
I am wanting to subtract one binary raster from another, for all images in a collection. For example if I have ten images, I want to subtract image 2 from image 1, image 3 from image 2, image 4 from ...
- 65
2
votes
1
answer
2k
views
Temporal segmentation algorithms using Google Earth Engine
I'm using the temporal segmentation algorithm Vegetation Regeneration and Disturbance Estimates - Verdet - for land cover change detection. The output layer is created but I can't display or export it ...
- 59
0
votes
1
answer
298
views
Land cover change - need help with land cover classes
I'm very much new to using ArcGIS and to this forum. For my thesis, I have a raster map of Indonesia where I only look at three types of land cover retrieved from the ESA-CCI dataset. These involve: ...
1
vote
0
answers
167
views
Map algebra raster calculator
I am attempting a GIS tutorial on land change analysis between two rasters. I have set the extent and raster analysis to what I have been given and used the expression below. However, it is not ...
1
vote
1
answer
261
views
Performing tag change detection in OpenStreetMap?
I'd like to have a tool for monitoring changes in OpenStreetMap (OSM) for tags only, not geometry. For instance, I'm interested in detecting any tag changes regarding one-ways in streets. This can be ...
- 1,285
4
votes
1
answer
517
views
Change Detection in ArcGIS Desktop?
I have two .las files derived from UAV photogrammetry. From there, in global mapper, I created a shapefile for each survey (one week apart), cropped to a shapefile.
Brought those two shapefiles into ...
- 41
3
votes
0
answers
69
views
Is there an OGC standard for data synchronization?
ESRI provides two solutions that facilitate synchronization. They are Editor Tracking for Feature Services (http://server.arcgis.com/en/server/10.3/publish-services/windows/editor-tracking-for-...
- 2,951
1
vote
1
answer
490
views
QGIS/SAGA Cross-tabulation error
I'm new to QGIS after using ESRI/ENVI/ERDAS products for years. I am trying calculate a cross-tabulated change image for post-classification change detection. After figuring out how to fix a ...
- 149
2
votes
1
answer
2k
views
How to calculate forest loss in google earth engine
I am using the method outlined in a previous question - Extracting land cover type in Google Earth Engine? - to identify habitat type and area with a defined polygon. I would now like to take this ...
- 103
1
vote
0
answers
266
views
Detecting change between 4 series times polygons (shapefiles) in R? [closed]
I have 4 series times shapefiles (my shapefiles are Polygons), my shapefiles are about urban(Urban land uses include: Agriculture,Built Up,Bare Land,Water), I want extraction change detection urban ...
3
votes
0
answers
259
views
Change Detection using Vector files [closed]
I have two shapefiles showing LULC of the same area for two different years; 1990 and 2015. Number of Polygons in two files are different but the number of class in both are same.
Is there any way ...
- 67
1
vote
2
answers
107
views
Population Change [closed]
I don't know if this site does general human geography, but since it's the only geography site I found this is the question. Population change takes into account 'growth rate' (which includes births ...
- 121