Discover and read the best of Twitter Threads about #Landsat
Most recents (17)
📢NEW PUBLICATION in Forest Ecology and Management: Pre-fire measures of boreal forest structure and composition inform interpretation of post-fire spectral recovery rates #OpenAccess #forestrecovery #boreal #fire
doi.org/10.1016/j.fore……
A short 🧵 follows...
doi.org/10.1016/j.fore……
A short 🧵 follows...
Spectral recovery=# of yrs reqd for pixel to attain 80% of its pre-disturbance NBR value (Years to Recovery, Y2R). NBR=Normalized Burn Ratio, which exploits differences in spectral response of vegetation & exposed soil in NIR and SWIR wavelengths. Enabled by #Landsat time series.
We used an #opendata synthesis of #boreal pre- & post-fire field measurements shared by Baltzer @forestecogrp et al. (2021). Incredibly useful data for examining drivers of spectral #forestrecovery post-fire.
Paper: doi.org/10.1073/pnas.2……
Data: doi.org/10.3334/ORNLDA…
Paper: doi.org/10.1073/pnas.2……
Data: doi.org/10.3334/ORNLDA…
My name is Dylan Blaskey, and I am a PhD student of Civil Engineering @CUEngineering and a research assistant @INSTAAR. I have spent my whole life around #Rivers and now I am researching them with @RiversArctic!
#ClimateChange | #RHRNClimate
#ClimateChange | #RHRNClimate
My work evaluates climate change impacts on #Arctic rivers, ice transportation corridors, fish, and Indigenous communities by weaving together observations, modeling, and Indigenous Knowledges. Find out more about @RiversArctic at colorado.edu/research/arcti…
My team recognizes the validity of #Indigenous knowledge and the right of these communities to shape research that occurs in their homelands. Because of this, an Indigenous Advisory Council guides all of our project’s communication, research design, analysis, deliverables.
How did agricultural land use upstream of the Aral Sea change in the last three decades? Here is our new #openaccess paper in @IOPenvironment: “Post-Soviet changes in cropping practices in the irrigated drylands of the Aral Sea basin”: dx.doi.org/10.1088/1748-9… (1/n)
The study area covers 650 000 km2 of drylands in #CentralAsia, covering #Uzbekistan, #Turkmenistan, and #Tajikistan and including the entire #AmuDarya and parts of the #SyrDarya basins. (2/n)
We computed seasonal spectral temporal metrics from the entire #Landsat archive (1987 to 2019) to produce annual maps of cropping practices using #GoogleEarthEngine #GEE. (3/n)
Las Vegas 1972 - 2022 | #Landsat #Landsat50 🛰️
Extra 1 | Overview of Las Vegas, Lake Mead, Hoover Dam & Colorado River - #Landsat 🛰️ false color composite - July 2022
Extra 2 | Las Vegas | Zooming-in on the NW zone.
Note that first images are a bit more blurry due to the lower spatial resolution of the first #Landsat satellites🛰️ More about it: usgs.gov/landsat-missio…
Note that first images are a bit more blurry due to the lower spatial resolution of the first #Landsat satellites🛰️ More about it: usgs.gov/landsat-missio…
⚠️⚠️ GUERRA DE UCRANIA - DÍA 12 ⚠️⚠️
1. Estamos en el 12º día de la invasión de #Ucrania por parte de las Fuerzas Armadas de la Federación de #Rusia y aliados. El presidente ruso advirtió que no parará hasta que los ucranianos abandonen la resistencia.
Hilo 7/03/20222.
1. Estamos en el 12º día de la invasión de #Ucrania por parte de las Fuerzas Armadas de la Federación de #Rusia y aliados. El presidente ruso advirtió que no parará hasta que los ucranianos abandonen la resistencia.
Hilo 7/03/20222.
2. Toda la información que puede reunir el día de ayer, la tienen en este otro hilo. 👇
3. Mapa general de los frentes de la guerra e información general. Las tropas rusas continúan avanzando, aunque sus movimientos sobre el terreno siguen siendo limitados, es decir, no hay grandes avances, como los primeros días. Parecen estar en proceso de acumular fuerzas. (ISW)
Last night's #Landsat spectral imagery (Feb 26, Local Time 21:22) reveal the location of major ongoing operations in #Ukraine: A closer look on Chernihiv urban area (hot spots marking very high temperature in short-wave infrared band 7) 1/5
Major concentrations of hot spots (marking very high temperature in short-wave infrared band 7) around of Chernihiv area, NE of Kiev 2/5
An interactive web app for creating timelapse of annual #Landsat imagery (1984-2021) for any location around the global. Built with #streamlit #geemap #EarthEngine. Go to streamlit.gishub.org and select "Create Timelapse" from the sidebar menu
GitHub: github.com/giswqs/streaml…
GitHub: github.com/giswqs/streaml…
Lake Mead water levels have dropped to a record low. These #Landsat images show the reservoir in 2000 (left) and 2021 (right). earthobservatory.nasa.gov/images/148758/…
Lake Mead is the largest reservoir in the United States and part of a system that supplies water to at least 40 million people across seven states and northern Mexico. It stands today at its lowest level since Franklin Delano Roosevelt was president.
This means less water will be portioned out to some states in the 2022 water year.
Sizing Up How Agriculture Connects to Deforestation: Using #Landsat data from the past two decades, scientists are starting to pinpoint which crops and farming styles have lasting impacts on forests.
earthobservatory.nasa.gov/images/148674/…
earthobservatory.nasa.gov/images/148674/…
Every year, scientists at the University of Maryland publish new data about the state of Earth’s forests based on observations from #Landsat satellites. In 2020, Earth lost nearly 26 million hectares of tree cover—an area larger than the United Kingdom.
research.wri.org/gfr/forest-pul…
research.wri.org/gfr/forest-pul…
What is driving this forest loss?
How much deforestation was due to wildfires? Food production? Forestry management?
The Sustainability Consortium & @WorldResources use satellite data to quantify the major drivers of annual forest losses.
How much deforestation was due to wildfires? Food production? Forestry management?
The Sustainability Consortium & @WorldResources use satellite data to quantify the major drivers of annual forest losses.
@K_VanTricht Relative diffs in digital numbers is key for classifier. But, some level of correction typically needed over large areas (multiple scenes), e.g., TOA to calibrate and accommodate for differences in view angle, etc.
@K_VanTricht If using ARD, suggest surface reflectance as physical values and more robust over time and space. Enable use of same image database for change detection and empirical modeling.
@K_VanTricht Lots to consider! DN -> TOA -> SR, when and how? Topic has developed, but great (classic!) paper on topic:
Song et al. 2001. Classification and Change Detection Using #Landsat TM Data: When and How to Correct Atmospheric Effects? #landcover
sciencedirect.com/science/articl…
Song et al. 2001. Classification and Change Detection Using #Landsat TM Data: When and How to Correct Atmospheric Effects? #landcover
sciencedirect.com/science/articl…
Just published the first chapter of my PhD on remote fossil site detection using satellite images & #unsupervisedlearning in @GorongosaPark with my supervisors @paleobob @carvalhoprimate
It is #openaccess at peerj.com/articles/11573/
@primobevolab @oxford_anthro @PeerJLife 1/n
It is #openaccess at peerj.com/articles/11573/
@primobevolab @oxford_anthro @PeerJLife 1/n
The paper starts by exploring the spatial and temporal gaps of the #primate & #hominid fossil record of Africa in the late #Miocene. @GorongosaPark in #Mozambique is shown to be a strategic location, with great potential to fill some major gaps in #paleoanthropology 2/n
We also discuss the difficulties of surveying for new paleontological localities, specially within modern forests/woodlands as in #Gorongosa, since dense vegetation cover reduces visibility (i.e. finding clues in topography and landscape). 3/n
The best-available-pixel (BAP) tool you have been waiting for! Implemented on #GoogleEarthEngine (#GEE). #Landsat
In #GEEBAP can tune composite parameters, create a #timeseries, set area of interest, AND download surface reflectance outcomes!
Try it out:
code.earthengine.google.com/e27240a92ecf64…
In #GEEBAP can tune composite parameters, create a #timeseries, set area of interest, AND download surface reflectance outcomes!
Try it out:
code.earthengine.google.com/e27240a92ecf64…
#GEEBAP documentation:
github.com/saveriofrancin…
#OpenScience support on best available pixel compositing:
White et al. 2014, tandfonline.com/doi/full/10.10…
Griffiths et al. 2013, ieeexplore.ieee.org/document/64153…
See White et al. for guidance on parameter selection related to phenomena of interest
github.com/saveriofrancin…
#OpenScience support on best available pixel compositing:
White et al. 2014, tandfonline.com/doi/full/10.10…
Griffiths et al. 2013, ieeexplore.ieee.org/document/64153…
See White et al. for guidance on parameter selection related to phenomena of interest
#GEEBAP implemented by @Saverio69588167, Saverio Francini, from @Geolab_unifi.
#Landsat #OpenData from @USGSLandsat.
#CloudComputing and tools: #GoogleEarthEngine, #GEE
Collaboration team: @txominhermos @IRSS_UBC (Coops) @Joanne_C_White @gheraiddo
#remotesensing #LTSBAP
#Landsat #OpenData from @USGSLandsat.
#CloudComputing and tools: #GoogleEarthEngine, #GEE
Collaboration team: @txominhermos @IRSS_UBC (Coops) @Joanne_C_White @gheraiddo
#remotesensing #LTSBAP
Massive new #QGIS plugin: #GEE Timeseries Explorer offers instant access to #EarthEngine image collections! Fetch #Landsat, #Sentinel2, or #MODIS #timeseries for any location and visualize images: geetimeseriesexplorer.readthedocs.io 🧵
Choose from our predefined collections, for instance merged & #cloud masked #Landsat TM, ETM+, OLI surface reflectance, cloud masked Sentinel2AB L2A, or just define your awesome custom collection in the built-in #Python editor.
Extract time series profiles for #training / #validation by clicking on map, or by navigating through vector point file. Download raw time series data for #sample-based workflows efficiently with parallel download.
Op het schiereiland Reykjanes wordt hard gewerkt aan de mid-oceanische rug. Dit soort aardbevingen gaan vaak gepaard met een magma-injectie in de korst, die ongeveer 10 km dik is onder dit deel van #IJsland (35 km onder Nederland. Soms leidt dat tot een spleetuitbarsting.
De aardbevingszwermen op het schiereiland Reykjanes, Z.W. #IJsland, blijven toenemen. Wie weet zit er wel een spleetuitbarsting in.
Mooi om te zien hoe de aardbevingen schommelen rond de as van van het Krýsuvík systeem. Er wordt daar flink wat magma geïnjecteerd.
📢 NEW PAPER! #PaperThread #SciComm
Master’s student @samherniman recently published an article about avian habitat suitability in Remote Sensing Applications: Society and Environment. Sam has written this thread summarizing his findings...
📖: doi.org/10.1016/j.rsas…
🧵:1/18
Master’s student @samherniman recently published an article about avian habitat suitability in Remote Sensing Applications: Society and Environment. Sam has written this thread summarizing his findings...
📖: doi.org/10.1016/j.rsas…
🧵:1/18
In general, when a habitat has more #birds, it also has more of all living things. In scientific terms, we say that birds are good surrogates or indicators of #biodiversity.
2/18
2/18
This is excellent, because counting birds is really easy. Many of them sing or call. So, we can do a field survey of birds in a habitat and use that number to find a relative count of all biodiversity.
more birdsong ≈ more birds ≈ more biodiversity
🦉🌲🐦🌳🦅
🐿️🪱🍂🍄🕷
3/18
more birdsong ≈ more birds ≈ more biodiversity
🦉🌲🐦🌳🦅
🐿️🪱🍂🍄🕷
3/18
#Tchernobyl : dans la nuit du 25 au 26 avril 1986, une série d’erreurs pendant un essai de sécurité entraînent l’explosion du réacteur n°4 et la fusion du cœur. La plus grave catastrophe nucléaire, longtemps la seule classée au niveau 7 sur l’échelle #INES, avant #Fukushima
#Tchernobyl, 2019, 33 ans depuis l’accident. Dites 33 : retour sur le rôle déterminant des #satellites d’observation dans le suivi de la #catastrophe : comme les nuages radioactifs, les satellites ne sont pas arrêtés par les frontières. Un #thread à dérouler… #space #nucléaire
En 2019, il semble facile d’avoir rapidement une image de n’importe quelle région du monde. Ici, la région et la centrale de #Tchernobyl , près de Prypiat, vue le 13/04/19 par le satellite européen #Sentinel2 (#Copernicus). Les images n’ont pas toujours été aussi disponibles…
Moving on from #Asteroids #Exoplanets #SolarEclipse #StarSpectrum we now focus on #Satellites
Sputnik 1 was the first satellite to be launched (1957). Over 1200 active satellites are currently orbiting Earth.
Check out the LIVE Satellite Map maps.esri.com/rc/sat/index.h…
Sputnik 1 was the first satellite to be launched (1957). Over 1200 active satellites are currently orbiting Earth.
Check out the LIVE Satellite Map maps.esri.com/rc/sat/index.h…
Satellites come in different sizes: from the size of a lunch box to that of a small school bus.
And they are used for different purposes: Climate Monitoring, Agriculture, Telecommunications, Research....
And they are used for different purposes: Climate Monitoring, Agriculture, Telecommunications, Research....
Can #CitizenScientists access data from these satellites?
Yes! NASA makes available near LIVE data from many of its satellites in an interactive interface.
Allows browsing full-resolution, global satellite imagery!
worldview.earthdata.nasa.gov
Use it for your projects!
Yes! NASA makes available near LIVE data from many of its satellites in an interactive interface.
Allows browsing full-resolution, global satellite imagery!
worldview.earthdata.nasa.gov
Use it for your projects!
