Welcome to Methods 3, Lecture 11
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Methods 3
timemanager plugin
but Carto can only animate points
source
it's possible to animate lines with some work
source
start with a series of lines with dates
densify to add more nodes to the lines
turn the densified nodes into points
3D in QGIS
what if I wanted to put this online without using Carto?
qgis2web
qgis2web
creates a webmap out of a QGIS map
it outputs a folder of code that creates the webmap
you can upload these files (drag-and-drop) to a site like neocities
you can upload these files (drag-and-drop) to a site like neocities
you'll need:
latitude and longitude for each feature
source
you'll also need:
an API key from google (requires a credit card)
source
<img style="width: 90%"
src="https://maps.googleapis.com/maps/api/
streetview?size=640x480&key=[YOUR API KEY]
&location={{latitude}},{{longitude}}&fov=60
&pitch=5" />
remote sensing
Landsat
the longest continuous satellite imagery collection program
Landsat is "earth observing", as opposed to people observing (spying)
1972: first Landsat satellite launched
1985: Landsat is privatized, run by Hughes and RCA
2001: Landsat fully returned to public hands
2007: all Landsat imagery becomes free
2013: Landsat 8 launched
Landsat imagery is used for:
- irrigated water monitoring
- irrigated water monitoring
- land cover mapping
- irrigated water monitoring
- land cover mapping
- land use change studies
- irrigated water monitoring
- land cover mapping
- land use change studies
- invasive species detection and monitoring
- irrigated water monitoring
- land cover mapping
- land use change studies
- invasive species detection and monitoring
- coastal wetlands monitoring
source
resolution: how much area on the ground is represented by one pixel
if a satellite has 30m resolution, each pixel represents a 30m x 30m square
a smaller number for resolution is better
temporal resolution
how frequently does the satellite take a picture of a given location?
bands
satellites produce a number of images at different wavelengths
bands 2, 3, and 4 (blue, green, and red)
source
band 6 and 7 (shortwave infrared)
source
you will combine bands to suit your needs
LiDAR
light detection and ranging
LiDAR actively uses lasers and sees how long it takes for a reflection to arrive
like SONAR (sound) and RADAR (radio waves)