You can find a demonstration video on how to use the application
here
Please contact us at
parastat@iacm.forth.gr if you have any questions, suggestions or issues with the application.
Landsat availability:
Landsat 4 is availability only with NDVI emissivity (July 1982 - December 1993).
Landsat 5 availability with MODIS and ASTER emissivity (March 2000 - December 2011), with NDVI ( January 1984 - December 2011 ).
Landsat 7 availability with MODIS and ASTER emissivity (March 2000 - present), with NDVI ( January 1999 - present).
Landsat 8 availability with all emissivities (March 2013 - present).
How to use the application:
1) Draw a polygon on the map by clicking (not dragging) on the map in order to select vertices of the polygon.
2) Select your preffered Landsat source. Please check the availabillity for each Landsat above.It is recommended to use MODIS and NDVI-based emmisivity for Urban/Peri-Urban areas
and ASTER emissivity for Natural/Isolated areas. Refer to the paper for more details.
3) Select your preffered emissivity source. Please check the important notes above about emissivity. For more details on this subject please refer to the paper.
4) Click the "Calculate LST" button.
5) The results will be presented below the map. For each LST result you will find a "show" button that displays the LST as a layer on the map and calculates the mean/min/max LST
value for the selected image. Also for each LST result you will find a "download" button that downloads the LST as a .tiff image. In order to download all the images click the "download
all" button at the end of the list. The downloaded .tiff is cut based on your polygon.
General Notes:
Landsat 4 is not compatible with MODIS and ASTER data due to their different operational period
Please use small polygons as GEE has a limit for the size of data that can be downloaded. We reccomend to search for areas below 10,000 km^2. In any case a message will appear to
inform you if you selected a big polygon.
You can change your polygon by pressing the "Draw a Polygon" after you have pressed "Calculate LST" to change the clipped area you want to download. You do not have to recalculate
the LST in order to download a different area within the current image.
All images are masked against water, snow, clouds and cloud shadows with fmask. Regions that are not showing LST means that are masked.
The statistics min and max are calculated using the following equations min = mean - 3σ(Standard deviation) and max = mean + 3σ
Update #4
Landsat 4 data have been integrated in the application. You can now search for LST images using the Landsat 4 thermal band from July 1982 to December 1993. Landsat 4. Since MODIS
and ASTER emissivity data are available after 2000, the option to use them along with Landsat 4 is disabled. Landsat 4 has a much smaller database of images, thus frequent "no images"
errors are excpected.
Update #3
Maximum date range increased. You can now search for a date range up to 6 months (previously was 1 month). In order for this feature to be implemented an aditional date input field
was created. Now you have to select 2 dates, "From" is the starting date and "To" is the ending date.
The filenames of downloaded tiffs changed from random generated to represent the LandsatID of the image for which the LST coresponds. Also changed the filename when all images are
downloaded together to "AllImages".
Added new collumn in the table of result with the name "Mean / Min / Max °C". After clicking the "show" button to show the LST image on the map, the mean, minimum and maximum temperature
of this image will also be calculated and displayed to the new collumn.
Changed the starting potision of the map to display the whole world instead of being focused on Europe.
Now after pressing the "Calculate LST" no LST image is shown on the map. You can select which one to display by pressing the "Show" button from the available ones.
Changed the list with available LST images to be sorted based on their date
Improved the contrast of the images.
Update #2
Added "Contact us" button. You can now contact us by filling the form.
Please let us know through this feature if you encountered any issues with the application or if you hace any questions requests and suggestions to improve it.
Update #1
USGS Landsat pre-collection updated with the new tier 1 collection. Landsat 7 and 8 are available up to the present date.
The paper describing the application is now published and available online
here.
New User Manual and updates button was added containing more information about the application. The updated logs documenting any changes to the application will be added there.
The default layer prefference for the map changed from "Map" to "Satellite". This option provides better contrast with the LST results palette.