Questions tagged [remote-sensing]

Collecting and interpreting information about the environment and the surface of the earth from a distance, primarily by sensing radiation that is naturally emitted or reflected by the earth's surface or from the atmosphere, or by sensing signals transmitted from a device and reflected back to it.

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1answer
376 views

How to Import the Multipolygon with GeoJSON code in Google Earth Engine?

I have to import a MultiPolygon in Google Earth Engine and what I have is just this. {"type": "GeometryCollection", "geometries": [{"type": "MultiPolygon","coordinates": [[[[102.0, 2.0], [103.0, 2....
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1answer
132 views

EVI2 value calculated from MODIS MOD09Q1 not bounded by -1 to 1

I'm trying to derive from MODIS 8 day composite MOD09Q1.006 product My formula follows the standard interpretation: EVI2 = 2.5(NIR-Red)/(NIR + 2.4*Red+1) I already know that MODIS bands for NIR ...
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0answers
137 views

Understanding difference between collocation and coregistration?

I'm a little confused on this topic. I need to put 2 SAR images into same coordinate grid. In ESA SNAP tool, there are 2 options: coregistration: Radar->Coregistration->Coregistration collocation: ...
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1answer
2k views

Export data from time-series image collection to a table in Google Earth Engine

On Google Earth Engine, I'd like to accomplish two tasks: extract data from every pixel, across a time-series, within the given geometry bounds and save it as a table. I need a column which prints ...
3
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1answer
60 views

What's is the difference between slicing and stacking in a time-series analysis?

My adviser told me that there are two categories of time-series in remote sensing: slicing and stacking. What is the difference between time-series stacking and slicing pertaining to landcover ...
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1answer
299 views

How to save training data set [pixel values] from earth engine during classification?

Link to Earth Engine code:https://code.earthengine.google.com/4da2d54d1ece4229b76c52a9d921ca70 Below I have pasted my code: function maskS2clouds(image) { var qa = image.select('QA60'); var ...
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1answer
25 views

Finding Cubesat Data for remote sensing dissertation? [closed]

Where can I find CubeSat data so that I can compare it to other satellite data for my dissertation?
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2answers
658 views

Pansharpen landsat mosaic in Google Earth Engine

Does anyone have a good way to pansharpen an entire mosaic of landsat 8 images? I would use the Panchromatic band (band 8). I have found tutorials on how to pansharpen a single image, but not for a ...
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0answers
49 views

Seeking Soil Mapping data in Southern Africa?

I am researching soil quality in Zambia but I’ve been unable to find georeferenced soil datasets (e.g. soil samples) for my area of interest. Specifically, I want to get yearly soil sampling data in ...
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1answer
45 views

Extracting DEM from PRISM data?

I have PRISM data which is in the following format. Are there any ways (software and methods) to extract the DEM or elevation information from these data files?
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2answers
744 views

Getting RGB values of each pixel in a LANDSAT 8 GeoTIFF with Python 3

I'm working with a set of LANDSAT 8 Collection 1 Tier 1 GeoTIFFS pulled from Google Earth Engine, and I need to find the RGB values of every pixel in this GeoTIFF. I've tried using the code from ...
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1answer
292 views

Interpolate biweekly NDVI to daily using Google earth engine

How to interpolate time series data using GEE? For example, the Landsat have 2-3 observations per month, I want to interpolate the series of NDVI to daily scale and get 365 observations a year, then ...
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3answers
1k views

Download MODIS/MCD19A2 AOD product with R

I'm looking for a programmatic way to download MODIS/MCD19A2 AOD data in R. So far, I've found a pretty solid R package called MODISTools that works nicely with the MODIS/VIIRS RESTful API. However, ...
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1answer
52 views

Know of any existing quality training/validation datasets for land cover?

Looking to do some moderate res. global land cover mapping and need as much training and validation data as possible--does anyone know of any good/quality land cover/land use data that are freely ...
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1answer
478 views

Extract Pixel Values for Multiple Polygons and Images

I have 21 polygons and for each polygon I want to extract the pixel values inside them for Sentinel 1 images from 2017-01-01 to 2017-06-30. The example below shows how this is done for one polygon. ...
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2answers
241 views

Strips/scratches on PlanetScope imagery

I'm doing a project that evaluates the practicality of using remote sensing imagery in agricultural field management. I noticed there are some scratches/strips on PlanetScope imagery for one of the ...
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1answer
29 views

Geolocation of L2G-Lite MODIS data

I would like to know if I am processing an L2G-Lite MODIS product, do I still need to geolocate, or reproject it to EPSG:4326? Or can I just leave it?
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1answer
95 views

Vegetation height estimation with QGIS

Is it possible to estimate vegetation ( crops) height using free of charge satellites, like sentinel or Landsat, with QGIS?
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1answer
108 views

import ARCSI as module in python

Any way to work with ARCSI (Atmospheric and Radiometric Correction of Satellite Imagery) like any other python package? Can it be imported in a jupyter notebook? >>>import arcsi or is ...
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2answers
298 views

Sentinel 2 Bands + Deep Learning

I am trying to classify 9 different classes of Land use deploying Resnet Architecture. Sentinel images come with 13 bands and in RS we normally combine different bands for different classes for ...
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1answer
540 views

How to convert a Feature Collection of one element (Multi Point Geometry) into a Feature Collection of different elements?

CODE: var l8 = ee.ImageCollection("LANDSAT/LC08/C01/T1_SR") .filterBounds(geometry); // TEST IMAGE var first = ee.Image(l8.first()).clip(geometry) // get image projection var proj = first....
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2answers
68 views

No Landsat across northern Australia in 1974-1977

Why there is no Landsat imagery available for the Gulf of Carpentaria, northern Australia, in 1974-1977? I have obtained imagery via USGS Earth Explorer from 1972 through to 2017, but there is a gap ...
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1answer
2k views

How to to extract coordinates of pixels inside a polygon in Google Earth Engine as a single feature? [duplicate]

IMPORTS: var geometry = /* color: #d63000 */ee.Geometry.Polygon( [[[-67.76435852050781, -22.213792811479802], [-67.76641845703125, -22.220785143658368], [-67.75646209716797, -22....
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1answer
80 views

How Do I search for MODIS data using pyModis?

I want to download the latest Modis vegetation Index Data(MODIS/Terra Vegetation Indices 16-Day L3 Global 250m SIN Grid V006) , whenever it is available for my Study Area. I know the Tile that my ...
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1answer
481 views

How to select all points of a polygon in google earth engine as a single feature?

IMPORTS: var geometry = /* color: #d63000 */ee.Geometry.Polygon( [[[-67.76435852050781, -22.213792811479802], [-67.76641845703125, -22.220785143658368], [-67.75646209716797, -22....
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1answer
131 views

Cloud Removal through Sen2cor for sentinel 2 images?

I have this imagery for an area of germany. According to docs of Sen2Cor, it states it can only remove haze and light clouds, i wanted to ask would it be possible to remove something as dense as shown ...
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1answer
295 views

Take pixel locations from rasterio raster and write out shapefile

I'm pulling a satellite image into python with rasterio, running some analysis to find a specific bounding box within that image, and then want to write those points out as a shapefile. I'm struggling ...
2
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0answers
231 views

authentication error for accessing data product on scihub through wget

I am new to Sentinel(overall remote sensing domain) and currently trying to download the data products from Scihub using the wget utility on Windows10 machine. However I am getting the below error. I ...
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1answer
117 views

I can apply tasseled Cap transformation in surface reflectance (not ToA)?

I can not understand if I should adjust the Tasseled Cap index with the surface reflectance values or the Top of Atmosphere
9
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1answer
1k views

Extracting values at specific latitude,longitude from MODIS swath data

I am trying to determine the amount of precipitable water vapor (PWV), ozone and aerosols as a function of time over specific spots on the Earth, namely our astronomical observatories. To do this, I'...
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1answer
92 views

Two Different Areas for the same Image in Google Earth Engine

IMPORTS: var polygon = /* color: #d63000 */ee.Geometry.Polygon( [[[-119.33364769821117, 46.05123532178373], [-119.3233620672313, 45.869732769408905], [-119.04111088542663, ...
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1answer
42 views

Is it possible to make a dictionary with 'multiple raster' variables?

Working in QGIS 2.14, I'm making a script to prepare images for remote sensing classifications. The user is prompted to enter multiple rasters for each band. I would like these rasters to be organized ...
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1answer
50 views

Seeking remotely sensed data for measuring urban gardens?

One of the students in my lab is currently seeking methods for measuring the very small size of urban green spaces in people's gardens. Is there a data set out there that may be appropriate for this?...
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1answer
813 views

Exporting data with different data types in Google Earth Engine. How to make data consistent to download?

I am working with Sentinel-2 data in GEE and I added NDVI and a specific SAVI as new bands to an Image. I had an error downloading 6 bands (RGBI, and VIs) because the data type is not the same: ...
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0answers
279 views

Aligning raster layers in python script

I am wanting to automate the preparation of raster layers from Sentinel-2 to be used in an unsupervised classification. So far, I have been able to write the following script, which will successfully ...
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1answer
74 views

SAR spectral signatures for oil spill detection from different sensors

I have a rather general question about supervised classification for oil spill detection. I want to apply supervised classification on the ESA SNAP dark spot detection tool results. My question is: if ...
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1answer
84 views

Getting features from a multi-spectral image [closed]

What are the features that are present in a multi-spectral image which can be used for classification? Also, how do we get these values from the multi-spectral image? I am using Python environment.
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1answer
358 views

Google Earth Engine data acquisition with a multipolygon shapefile uploaded as table asset

I uploaded a shapefile with some polygons of my area of study as a asset table in Google Earth Engine. Now I am trying to export the displayed data (several Sentinel-2 bands) as GeoTIFF to my Drive ...
-1
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1answer
89 views

Seeking data for image fusion of satellite and UAV/ drone data?

I'm new to Remote Sensing and Data Processing, and interested in fusion. Where do I find georeferenced data that can be fused together? It can be either of the following: Satellite image and ...
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1answer
91 views

Sentinel-2 Swath identifiers

Is there a standard way of referring to a repeat-swath of a Sentinel-2 MSI acquisition? For example the swath shown in the figure below is repeated every 5 days. (Here it is further split in to ...
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0answers
130 views

Performing Object Based Image Analysis with NAIP?

I use NAIP imagery (primarily in QGIS/GRASS) for agricultural analysis. I want to separate out objects such as grain silos, farms, buildings, &c. using segmentation and classification. Is this ...
3
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0answers
750 views

Image Segmentation and Object-based Classification in Google Earth Engine [closed]

I have tested three methods to segment my image collection: (https://code.earthengine.google.com/699f04706c114260068275acd2605644) var l8sr = ee.ImageCollection('LANDSAT/LC08/C01/T1_SR'); function ...
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3answers
1k views

Atmospheric correction algorithm in Python or R for Landsat 7 ETM+

I am looking for an algorithm which can be tuned in python or R for atmospheric correction for Landsat 7 ETM. Searching Google I have found only a few algorithms in ENVI or ERDAS which are not ...
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1answer
114 views

Aggregating/Averaging NDVI across pixels. Arithmetic mean seems bad choice

I need to compute an aggregate index for vegetation density in certain (large) shapes, to assess desertification. I have NDVI data at a high spatial resolution (~100 NDVI-pixels per aggregation shape, ...
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1answer
220 views

Exporting 16bit tiff sattelite imagery with the stretch/colour-balance applied by Arcmap?

Problem: I have 16-bit satellite GeoTIFFs from DigitalGlobe (QuickBird/WV2), which I wish to share with a colleague that does not have access to GIS software. When loaded into ArcMap, these ...
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1answer
145 views

How much do leaves on/off affect the number of LiDAR ground returns?

We would like to collect a generic purpose topographic LiDAR dataset over a large region in Belgium. Our minimum requirement is to achieve at least 1 point/m² on the ground. Ideally, we would like to ...
2
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1answer
130 views

Is image registration necessary among temporal Landsat images?

I am working on a project comparing each pixel every 4 years for the same AOI from Landsat Images (1986-2017). It involves with Landsat 5, 7 and 8 images. Do I need to perform image registration as ...
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0answers
43 views

How to Substract one image band from the subsequent in Google Earth Engine?

i am trying to find the day of year (doy) for each year with the highest change in NDVI compared to the day before, to map in the end a shift in start of season. My code to seperate each year so far (...
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1answer
290 views

Masking cloud pixels for NDVI in QGIS

I'm using QGIS to analyze some image of the NOLA area pre- and post-hurricanes. I'd like to calculate NDVI and a couple other indices for the images, but I want to exclude pixels with clouds in them ...
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1answer
91 views

Whether Sentinel 3 OLCI can be used as a MODIS replacement for 250m NDVI?

Based on the bandwidths MODIS bands 1 and 2 (620nm - 876nm) will match S3 bands Oa7 - Oa17 (620nm - 865nm) I am just trying to know if anyone had any experience in using S3 data instead of MODIS for ...