MODIS products

[mjalex14]

Hello, it appears that the data on this directory are not available anymore.

https://e4ftl01.cr.usgs.gov/MOLT/MOD13Q1.061/

nothing from MOLA either. any issues with the servers? how can i get the NDVI data in hdf from modis? 

[Miguel Jimenez]

Hi!

Thanks for reaching out. We are aware that some of the LPDAAC's collections were recently removed from the Hyrax content list. We are reaching out to LPDAAC to better learn about if these collections will be restored and made available again via the OPeNDAP service.

In the mean time, this collections is still findable, and downloadable as hdf via Earthdata Search. For example entering: 

MODIS/Terra Vegetation Indices 16-Day L3 Global 250m SIN Grid V061 

On the search box will produce the available granules and hdf for the MOD13Q1 data product. Here is the link:

https://search.earthdata.nasa.gov/search/granules?p=C1748066515-LPCLOUD&pg[0][v]=f&pg[0][gsk]=-start_date&g=G3588184518-LPCLOUD&q=MODIS/Terra%20Vegetation%20Indices%2016-Day%20L3%20Global%20250m%20SIN%20Grid%20V061&tl=1351108398.665!5!!

Best regards, 

Miguel Jimenez-Urias, PhD
Computational Oceanographer | Sc. Community Director
OPeNDAP, Inc

https://www.linkedin.com/in/MiguelJimenezUrias/

[Miguel Jimenez]

Hi again, 

I heard back from the LPDAAC and it looks like the OPeNDAP service point is back up again. You should be able to access MODIS products.

For example:

https://opendap.cr.usgs.gov/opendap/hyrax/MOD13Q1.061/contents.html

Thanks again for reaching out!

Miguel Jimenez-Urias, PhD
Computational Oceanographer | Sc. Community Director
OPeNDAP, Inc

https://www.linkedin.com/in/MiguelJimenezUrias/

[mjalex14]

Hi Miguel,

Thank you very much for the information. I am more interested in the catalogs in these links https://e4ftl01.cr.usgs.gov/MOLA/MYD13Q1.061/

Looks like all MODIS data are missing from the MOLA and MOLT folders. something you can look into ?

Theo

[Miguel Jimenez]

Hey Theo, 

I am not familiar with that system. Hmm, was that an opendap service?  I am afraid to say that I do not know who to contact to make the original h5 files on the source url link you provided. 

I see that the MOD13Q1.061 files on the OPenDAP end point url I provided

https://opendap.cr.usgs.gov/opendap/hyrax/MOD13Q1.061/contents.html

are in an aggregation (ncml), as opposed to the .h5 files that you were accessing data originally, and the file hierarchy has been flattened (to support client APIs that do not support that behavior). That may break your workflow. 

If you decide to give it a try, you can request to download some data using OPeNDAP’s Data Request Form as download as nc4. NOTE: Since these files are aggregated (each files covers 582 time units), you may hit a download limit imposed by NASA if you attempt to download each ncml file on its entirety (NASA currently imposes a MAX 2GB per download request). To avoid this you may want to limit the number of variables and the time range to avoid hitting the limit per request.

Apologies for not being able to help restoring your preferred endpoint service on your original URL.

Miguel Jimenez-Urias, PhD
Computational Oceanographer | Sc. Community Director
OPeNDAP, Inc

https://www.linkedin.com/in/MiguelJimenezUrias/

[mjalex14]

Hi Miguel, thank you for the details explanation and help on this topic. For the past several years I was using this link to get the MODIS TERRA and AQUA NDVI files but it looks like the MOLA/MOLT/ folders are missing. https://e4ftl01.cr.usgs.gov/

I will try to get my way around with Opendap. Something new to discover I guess.

Thank you and kind regards, Theo Gkousarov

[mjalex14]

This link explains about the data not being available as they are moved to the cloud. I guess I need to work around that. The opendap comes with issues, but working on it. thanks

https://www.earthdata.nasa.gov/data/alerts-outages/lp-daac-discontinue-data-pool-distribution-modis-datasets

[Miguel Jimenez]

Hi Theo,


You are correct. There is an ongoing effort to migrate data to the cloud from NASA, and some of the on-premises services are being “deprecated”. OPeNDAP can run on the cloud, and while right now LP DAAC (USGS) OPeNDAP service is on premise, but will likely migrate to the cloud. OPeNDAP’s Hyrax data server, whether running on the cloud or on premise, looks the same to the end user. So spending some time on accessing data via opendap, even as services move to the cloud, is not a bad idea.



That said, what do you usually use to access/access data? OPeNDAP is mostly a (data-proximate) subsetting tool, and so I would discourage to attempt to download the entire ncml file. There are various APIs that can pass along “subsetting instructions” to the data server so the user only gets what is requested. But each API usually requires some patience and a little bit of effort. And I can help of course!

[mjalex14]

Hi Miguel, I am back to the tast now...

What I want to do is download the latest 16day 250m NDVI data for the UK (tiles H18v03 and H17v03). Then I want to download the same tiles for the same period, but for previous years. That way I can create the anomalies lets say for the first days of August compared to the same period over the past years. I dont see how this can be done with opendap in the ordering form.

Any help much appreciated.