6

Per https://lpdaac.usgs.gov/dataset_discovery/modis, the viewing swath width of MODIS is 2,330 km, thus a large portion of the image is off-nadir in some way. https://modis.gsfc.nasa.gov/about/specifications.php The following forum post gives an explanation of how to calculate pixel size based on viewing position. (Note: still an estimate due to factors ...


3

Downloading data for the whole planet using MODIS MOD13Q1 250m product will generate quite a large dataset and that's probably why ModisDownload collapsed. Instead, you can try to use MODIStsp package which is much more robust (in my opinion) and holds very advanced features for downloading, mosaicking, and processing MODIS data. Check it out here: https:...


2

The problem was related to the new policy by NASA that an authentication is needed for any download from their data portals. The ModisDownload function in the rts package is now updated, and supports the new changes. Follow the help page of the function in the new version of the rts package, to see how you can set your username and password on your machine ...


2

should be aware that ftp is used while the page is http, this line should be reviewed carefully FTP <- http://e4ftl01.cr.usgs.gov/MOLT/MOD13Q1.005/


2

This has been an issue with the MODIS Reporjection Tool, as the files you are trying to download are placed in different folders on their server and the code often fails to parse through each of them. Use the MODIS Data Download Manager through the LP DAAC web portal. 1) This link will take you to the portal with the download manager. Click on LPDAAC2Disk ...


2

Extract of MODIS REPROJECTION TOOL USER’S MANUAL: Resample (section) -u UTM_zone Output zone number, relevant only for UTM projections. Valid values are –60 to +60. Then, if you want to reproject to UTM Zone 20S, use UTM_zone = -20. I've doing it, and works perfectly.


1

Thank you @AndreJ. This is indeed the problem and Mike from that post was helping me with this problem in a separate forum (http://r-sig-geo.2731867.n2.nabble.com/Reproject-MODIS-data-using-R-results-in-NAs-or-no-spatial-extent-td7592500.html). The problem is that the metadata is incorrect. The MODIS GLASS product is in the cylindrical equidistant ...


1

The MODIS package received a comprehensive update (starting with version 1.1.3) which covers the deprecation of LAADS FTP and its migration to HTTPS and fixes known download issues related to the automated download from LP DAAC and the newly introduced NSIDC (MODIS snow and ice products) servers. See NEWS for a detailed change log. Using an arbitrary ...


1

I found the solution : the servers goes offline 1 or 2 days a week to push new MODIS images. So you will have this error some days each week.


1

The following code worked for me: # list all the filenames of each tile in a text file and make sure they are identical order (filenames) #read them as arrays readarray a < Mod24v05list.txt readarray b < Mod25v05list.txt readarray c < Mod24v06list.txt readarray d < Mod25v06list.txt for (( i=0; i <= ${#a[@]} ; ++i )) do a1="${a[i]}" b1="${b[i]...


1

At first glance, I'd expect the issue to be that you are trying to use the MODIS Reprojection Tool (which is designed for tiled and georeferenced data) and not the MODIS Reprojection Tool Swath (which is designed for the swath data). When working with the swath data, it is a bit more complex, and you'll usually also need the geolocation file from the ...


1

It's a bug, MRTSwath has problems with V006 collection, I don't know why (MRTSwath last version is from 2010, it's too old). Try with HEG. For geolocation file, go to Level-1 and Atmosphere Archive & Distribution System. You'll find MOD03 Geolocation 1 km file.


1

How do you mosaic your images? I do believe that it doesn't throw away the other bands. If you keep all the bands from the input HDF-bands, then the problem arises in SPECTRAL_SUBSET = ( 1 ) - where you specify that you want the first band only, while ignoring the rest. The first band in MOD13Q1 is NDVI, EVI is the second. To fix that, you should have ...


1

ArcGIS doesn't handle HDF files very well, so you might need to use some other methods to extract the data. You could use the MODIS Reprojection Tool, or if you have access to ENVI/IDL, you can use them to read and export the data.


1

This is not a full answer to the question. It answers specifically how to render Water Vapor Near Infrared retrievals data on a map. How do I convert the Water_Vapor_Near_Infrared data so that it can be projected onto a map? If you look at the Metadata included in the MOD05_L2 product you would notice that there is a difference here. Water Vapor ...


1

You do not need to modify the parameter file on the fly. Instead, when you call the swath2grid.exe, you can use the -if= switch to set the input file, the -gf= switch to set the geolocation file, and the -of= switch to set the output file, while keeping all the other parameters from the specified .prm file. An example from a .bat file used for processing a ...


1

I use cygwin Linux shell under Windows OS. You should install Cygwin firstly. Then create MRT .prm file of single stage (this you have done for fewer images) by using MRT tool. Put this .prm file with all modis tiles under same folder such as test. Open .prm with txt and you could modify some parameters. #INPUT_FILENAMES = ( D:\2000\049\MOD09A1.A2000049....


1

pyModis, specifically the modis_mosaic and modis_convert scripts can use either MRT or GDAL to mosaic and/or reproject the data (see modis_mosaic.py documentation). If pyModis somehow fails for your specific use case you can still use it to download the data and then reproject it with the Modis Swath Tool.


1

You would have to take a good hard look at the script to make sure the the code structure is appropriate for atmospheric MODIS data and that it is as simple as calling a different exe. Since this is a different data format, I highly doubt that it is as simple as calling a different processing program, but one can hope. As far as calling the ...


1

If you don't specify the target resolution in gdalwarp, it makes an educated guess of what could make sense. In most cases, it uses an average of the x and y resolution of the source data. But if you reproject from meters to degrees, this might go wrong. So you better set the target resolution or size with tror -ts (but not both!) explicitely each time. I ...


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