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Questions related from Nikolaos Tziokas
I'm performing a simple linear regression with one dependent and one independent variable: dependent variable (y): Nighttime lights raster, Independent variable (x): Population raster. The issue...
27 June 2025 8,789 3 View
Using the terra package, I want to remove island pixels (or isolated pixels) from a categorical raster with 1 category. I want to remove pixels with area smaller than 25000 m, given that the pixel...
17 May 2025 8,441 1 View
I want to use asymmetric Gaussian filter to smooth an image, because I don't want the equal smoothness in vertical and horizontal (with different size of standard deviation, σ). This means that I...
28 March 2025 7,126 1 View
I have two monthly rasters (LST landsat 8) for the months July and August. I want to create another raster for the month June. How should I proceed? I was thinking to take the mean but it doesn't...
10 September 2024 6,778 3 View
I ran PCA on 4 variables using the prcomp library. All variables were normalized to have a mean of zero and a standard deviation of one (z-score) before the PCA. prc 1 and I performed a varimax...
27 June 2024 6,839 1 View
I have 12 raster images which I stack them. Then I converted the rasterstack to a matrix, I remove the NA's from the matrix and I convert the matrix to monthly time-series matrix. Finally, I run...
23 December 2023 271 0 View
My goal is to download the monthly mean Red band (B4) from Landsat 8 for the year April 2013 to December 2022 (total 117 monthly mean images) using Google Earth Engine (GEE). For this reason I am...
09 December 2023 4,552 0 View
I downloaded NASA's Black Marble daily product (VNP46A2) which is in h5 format. One needs to preprocess the data using the Scientific Data Sets (SDS) included in the h5 file. Based on the User...
08 November 2023 8,266 0 View
I'm trying to download single NDVI image from Proba-V. Proba-V produces images every 2 days. Here (https://developers.google.com/earth-engine/datasets/catalog/VITO_PROBAV_C1_S1_TOC_100M) is the...
30 May 2023 8,136 2 View
I want to download Black Marble daily nighttime lights (NTL) using Google Earth Engine (GEE). My question is if the pixel values of the images are in digital numbers (DN) or radiance. Here is a...
22 May 2023 879 4 View
In R, I am using the randomForest and caret packages for a Random Forest (RF) regression task. Genarally, there are two options when fine-tuning a model: GridSearch, RandomSearch. I have seen on...
03 April 2023 3,193 3 View
I am trying to export yearly median MODIS-based NDVI products at 250m spatial resolution. I am using the 16 day MODIS/061/MOD13Q1 product. I have found this code which I am following...
26 January 2023 4,056 4 View
Luojia 1-01 is the NTL satellite designed by Wuhan University, launched in June 2018. Right before Christmas I was able to download it's data from here (http://59.175.109.173:8888/app/login.html)...
15 January 2023 3,888 2 View
I have three raster layers, two coarse resolution and one fine resolution. My goal is to extract GWR's coefficients (intercept and slope) and apply them to my fine resolution raster. I can do this...
03 December 2022 2,749 1 View
I want to downscale a satellite image using a deep learning approach, called extended super-resolution convolutional neural network (ESRCNN). The paper of the method is 'Deep learning-based fusion...
15 October 2022 9,305 2 View
I am utilizing Area-to-Area CoKriging (AtACoK) for raster downscaling in R using the atakrig package. For this purpose I have one dependent variable (let's say x) with pixel size of 400m and 2...
18 February 2022 3,908 7 View
Is there any polygon shapefile of slums in New Delhi? This paper (Emissions inventory of anthropogenic PM2.5 and PM10 in Delhi duringCommonwealth Games 2010) showed a map of the slums but I can't...
21 January 2022 570 1 View
Hi, I am new to DL and I'm trying to classify 1 Landsat8 image into 3 categories using VGG-19. I am using 8 bands (B2 to B7 ,B10 and Panchromatic). I performed the sampling procedure and my...
12 September 2021 3,930 3 View
Dear all, My goal is to predict night light intensity based on day time satellite imagery. I am using data from VIIRS and Landsat 8 sensors. My study area is shown in the attached image and I am...
23 June 2021 5,118 3 View
I have 4 images of the same area captured in Green, Red, NIR and Rededge band. I want to transform the DN values into Reflectance. Do I need to create a single image first, by composite the 4...
21 December 2017 9,300 3 View
Hi, I was wondering if there are yearly socioeconomic spatial data for India (e.g. population distribution, energy consumption) for the period 2013-today. So far, i managed to find population...
01 January 1970 7,473 8 View
I am looking for a list of global cities. By global city I mean "Global cities are major “corporate and financial hubs” in a “global web of linkages”, based on the functional perspective in urban...
01 January 1970 3,886 12 View
This might be a silly question but I got confussed. I am using the Tree Cover Density (TCD) raster layer from EEA...
01 January 1970 8,331 2 View
I have 1 dependent variable (y1) and 2 independent variables (x1, x2) in raster format. I want to choose the best, single, variable for simple linear regression. My goal is two-fold: After...
01 January 1970 722 4 View
Hi, I would like to ask what type of majority filter (e.g. mean, median) is recommended for continuous data (land surface temperature)? Also, does the pixel size of my raster layer (1km) affects...
01 January 1970 4,877 8 View
I am about to use the BFAST Lite (BFAST Lite: A Lightweight Break Detection Method for Time Se... ) algorithm to perform a satellite time-series analysis (STSA). One of the parameters I have to...
01 January 1970 1,628 1 View
Imagine a sensor (let's call it sensor A) that captures images in two viewing angles, near-nadir (NN) and off-nadir (ON). The task is to downscale (DS) the images. Assuming, for validation, there...
01 January 1970 3,332 1 View
