[R-sig-Geo] Earthdata CMR access

[Joe Lee]

Yes, that's the hard part that I'm referring to.

Once you pass that step, you may also want to look at another example in MATLAB [1]
to access PODAAC data on S3 using the temporary token.

I'd really appreciate your effort if you can share a working R-code project 
that can both search with CMR and then access NASA data on S3.

Regards,

[1] https://www.hdfeos.org/zoo/PODAAC/ATM_SURFACE_TEMP_HUM_WIND_PRES_day_mean_ECCO_V4r4_nc_c.m


-----Original Message-----
From: Ben Tupper <btupper using bigelow.org> 
Sent: Wednesday, April 13, 2022 1:09 PM
To: Joe Lee <hyoklee using hdfgroup.org>
Cc: r-sig-geo using r-project.org
Subject: Re: [R-sig-Geo] Earthdata CMR access

Hi,

I was planning to use the httr package or the newish httr2 package which should be able to handle the transactions.  Once a resource is tracked down via search, I plan to use the ncdf4 package to access.

I can add headers to the http requests, so presumably that can include tokens.

But I am finding even the simple stuff like using the API to generate a token, as shown here https://wiki.earthdata.nasa.gov/display/EL/How+to+Generate+a+User+Token
,  to be challenging.  Thud!

Ben

httr: https://CRAN.R-project.org/package=httr
httr2: https://CRAN.R-project.org/package=httr2
ncdf4: https://CRAN.R-project.org/package=ncdf4

On Wed, Apr 13, 2022 at 1:03 PM Joe Lee <hyoklee using hdfgroup.org> wrote:
>
> Hi,
>
> I'm also interested in the solution that you're seeking since I've 
> written a Python-equivalent CMR+OPeNDAP workflow a very long time ago [1].
>
> It's both very tricky and difficult nowadays because NASA tries to 
> constrain AWS egress cost via Earthdata Login authentication.
>
> Does R provide a cURL-like library + a temporary token-based authentication?
>
> [1] 
> https://earthdata.nasa.gov/collaborate/open-data-services-and-software
> /api/opendap/gesdisc-airs-opendap-cmr
>
>
> -----Original Message-----
> From: R-sig-Geo <r-sig-geo-bounces using r-project.org> On Behalf Of Ben 
> Tupper
> Sent: Wednesday, April 13, 2022 11:41 AM
> To: r-sig-geo <r-sig-geo using r-project.org>
> Subject: [R-sig-Geo] Earthdata CMR access
>
> Hello,
>
> I am interested in accessing physical oceanography data from PO.DAAC (
> https://earthdata.nasa.gov/eosdis/daacs/podaac) from within R using 
> opendap.  NASA is moving its data offerings to the cloud, and it is 
> adopting Common Metadata Repositories ("CMR",
> https://cmr.earthdata.nasa.gov/search/site/docs/search/api.html) for searching.  CMR searching is in lieu of searching THREDDS catalogs.
>
> I'm finding the on-ramp to using CMR tricker than I had expected given the sales pitch behind CMR (or maybe the wheels have come off my car!)  I am wondering if anyone in this community has waded into using R-based CMR to access cloud-based geospatial data, and, if so, might be willing to share some insights or provide guidance?
>
> Regards,
> Ben
>
> --
> Ben Tupper (he/him)
> Bigelow Laboratory for Ocean Science
> East Boothbay, Maine
> http://www.bigelow.org/
> https://eco.bigelow.org
>
>         [[alternative HTML version deleted]]
>
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--
Ben Tupper (he/him)
Bigelow Laboratory for Ocean Science
East Boothbay, Maine
http://www.bigelow.org/
https://eco.bigelow.org