Where do satellite sensors measure the land surface temperature from?
It is estimated from Top-of-Atmosphere brightness temperatures from the infrared spectral channels of a constellation of geostationary satellites (Meteosat Second Generation, GOES, MTSAT/Himawari). Its estimation further depends on the albedo, the vegetation cover and the soil moisture.
What is Modis LST?
Overview. The Land Surface Temperature (LST) and Emissivity daily data are retrieved at 1km pixels by the generalized split-window algorithm and at 6km grids by the day/night algorithm.
How do you calculate Landsat land surface temperature?
How to calculate Land Surface Temperature with Landsat 8 satellite images
- TOA (L) = ML * Qcal + AL
- BT = (K2 / (ln (K1 / L) + 1)) − 273.15.
- NDVI = (Band 5 – Band 4) / (Band 5 + Band 4)
- Pv = Square ((NDVI – NDVImin) / (NDVImax – NDVImin))
- ε = 0.004 * Pv + 0.986.
- LST = (BT / (1 + (0.00115 * BT / 1.4388) * Ln(ε)))
What affects land surface temperature?
Parameters of climate phenomena The ocean on the Earth’s surface accounts for approximately 71% of the global total area and is an important factor affecting the thermal distribution, atmospheric circulation, weather changes and climate differences on the land surface52.
Can a satellite measure temperature?
Satellite temperature measurements are inferences of the temperature of the atmosphere at various altitudes as well as sea and land surface temperatures obtained from radiometric measurements by satellites. Weather satellites do not measure temperature directly. They measure radiances in various wavelength bands.
How do you measure ground surface temperature?
Surface temperature is measured with a hand-held Infrared Thermometer (IRT) that, when necessary, is wrapped in a thermal glove or has been placed outdoors for at least 30 minutes prior to data collection. The instrument is pointed at the ground to take surface temperature readings.
What is Modis surface reflectance?
The MODIS Surface Reflectance products provide an estimate of the surface spectral reflectance as it would be measured at ground level in the absence of atmospheric scattering or absorption.
What was the Modis product identifier?
The product name on the MODIS ordering site is: “MODIS/Terra Calibrated Radiances 5-Min L1B Swath 1KM V005”. In addition you can obtain daily scenes at higher spatial, but lower spectral, resolution. Files with 500m resolution contain the 7 bands of data in the Visible, Near-IR and Mid-IR parts of the spectrum.
What is LST used for?
LST has been used to examine the consequences of land cover changes on climate (Li et al., 2015), and to investigate the association between maximum thermal anomalies, heat waves, melting ice sheets, and droughts in tropical forests (Mildrexler et al., 2018).
What is the difference between land surface temperature and air temperature?
Surface temperatures over land have traditionally been measured at weather stations. However, satellites measure how hot the land surface temperature (LST; including the uppermost parts of e.g. trees, buildings) are to touch, whereas weather stations measure the air temperature just above the surface (T2m).
Why is land surface temperature?
Altitude plays a clear role in temperatures, with mountain ranges like the North American Rockies cooler than other areas at the same latitude. Scientists monitor land surface temperature because the warmth rising off Earth’s landscapes influences (and is influenced by) our world’s weather and climate patterns.
Why is land surface temperature important?
Land Surface Temperature is an important variable within the Earth climate system. It describes processes such as the exchange of energy and water between the land surface and atmosphere, and influences the rate and timing of plant growth.
How are LSTs and surface emissivities retrieved in MODIS?
In the day/night algorithm, daytime and nighttime LSTs and surface emissivities are retrieved from pairs of day and night MODIS observations in seven TIR bands. The product is comprised of LSTs, quality assessment, observation time, view angles, and emissivities.
How are satellite data used to measure air temperature?
These observations are used to retrieve land surface temperature (LST 3 ,), and gridded records are available that provide continuous estimates of LST in both space and time. Ideally, satellite retrievals of LST could be used to fill gaps of surface measurements of air temperature in both space and time.
Which is the best algorithm for land surface temperature?
The MODIS land surface temperature algorithm provides estimates of daytime and nighttime LST at a monthly time step at 0.05° spatial resolution 3, 14 in the MYD11C3 product (we use collection 5 available from the NASA LPDAAC website https://lpdaac.usgs.gov/ ).
What is the importance of land surface temperature?
Land surface temperature (LST) is one of the key parameters in the physics of land surface processes from local through global scales. The importance of LST is being increasingly recognized and there is a strong interest in developing methodologies to measure LST from space.