update satellite info

lectures/geospatialdata.html

@@ -35,8 +35,9 @@ <h3>Professional mapping technologies</h3>
 <p>
 <ul>
  <li class="fragment">passive and active aerial and satellite sensors
- <li class="fragment">ground-based surveys : (RTK)GPS, total station, lidar
- <li class="fragment">in situ sensors: e.g., air quality, river stages, water quality, soil moisture
+ <li class="fragment">ground-based sensors: (RTK)GPS, total station, lidar
+ <li class="fragment">in situ sensors for measuring environmental variables
+ such as air quality, river stages, water quality, soil moisture
 </ul>
 <p class="fragment">
 Emergence of autonomous platforms: air, ground, water </p>
@@ -48,14 +49,14 @@ <h3>Professional mapping technologies</h3>
 
 <section>
    <h3>Remote sensing: passive</h3>
-<p>Numerous satellite and airborne platforms and sensors, e.g:  
+<p>Numerous satellite and airborne platforms and sensors, for example:  
 <ul>
  <li class="fragment"><a href="https://www.usgs.gov/core-science-systems/nli/landsat">
-Landsat 1-8:</a> landcover since 1972, 30m, multispectral 
+Landsat 1-9:</a> landcover since 1972, 30m, multispectral 
  <li class="fragment"><a href="https://terra.nasa.gov/">
-Terra:</a> MODIS temperature 250m; ASTER radiance, DEM 15m  
- <li class="fragment"><a href="https://earth.esa.int/web/sentinel/user-guides/sentinel-2-msi">
-SENTINEL-2 MSI:</a> landcover, 10m, multispectral
+Terra:</a> MODIS temperature 250m; ASTER radiance, DEM  
+ <li class="fragment"><a href="https://sentinels.copernicus.eu/web/sentinel/home">
+SENTINEL-1 5P:</a> landcover, temperature, ocean currents, atmosphere, multispectral
  <li class="fragment">
 <a href="https://www.planet.com/company">
 PLANET:</a> new generation of small satellites: 170 small satellites mapping Earth daily at 3m resolution