pre-submission inquiry for MODIStsp

[lbusett]

Dear all,

In relation with this:

https://github.com/ropensci/unconf17/issues/67

, we are considering to submit our MODIStsp package for inclusion in rOpenSci.

In short, MODIStsp allows automatizing the creation of time series of satellite images derived from NASA MODIS Land Products data. It allows to perform several preprocessing steps (e.g., download, mosaicing, reprojection, resize, data extraction) on MODIS data available within a given time period, exploiting a user-friendly GUI for selection of processing parameters.

Additional informations can be found on MODIStsp website, as well as on a manuscript published on Computers and Geosciences (https://doi.org/10.1016/j.cageo.2016.08.020)

The package is already on CRAN, and hosted on GitHub.

Before starting the submission process (which will require some work for re-shaping a bit the package to better adhere with rOpensci standards), we'd like to ask if the package would be considered appropriate for submission and useful for the community.

Thanks in advance for your feedback,

regards,

Lorenzo Busetto

[maelle]

Thanks a lot @lbusett to consider a submission to rOpenSci! Two questions to help discussion:

• Which NASA API does MODIStsp interact with?

• What are scientific applications of the retrieved data? Any specific examples?

[lbusett]

Hi,

thanks fot the prompt reply. I reply below to your questions:

• MODIStsp doesn't use an API. It accesses the NASA http (https://e4ftl01.cr.usgs.gov/) and/or ftp (ftp://ladsweb.nascom.nasa.gov/allData) online archives to search all the MODIS images available on the time and space range selected by the user and downloads data from there using httr::get() or Curl::getURL requests. As far as I know, however, no APIs for "generalized" access to MODIS land products exist at the moment. ORNL DAAC has a ordering/subsetting webservice (https://modis.ornl.gov/data/modis_webservice.html), but it is limited to a small subset of available MODIS product. NSIDC also provides an API for access, but only for Snow/Ice products (https://nsidc.org/support/how/how-do-i-programmatically-request-data-services). MODIStsp allows access to all (more then 100) current MODIS land products, with the possibility to easily add new ones

• MODIS satellite data are used in many different scientific applications, since they allow global daily monitoring of the earth surface. Their applications are therefore too many to analyze in this context. Among the main ones, I can cite (borrowing a bit from wikepedia...) the monitoring of vegetation health by means of time-series analyses with vegetation indices, the analysis of long term land cover changes (e.g. to monitor deforestation rates), real time monitoring of snow/ice cover, analysis of water quality and of impacts of floodings, change of water levels of major lakes and the detection and mapping of wildland fires. MODIS data are also extensively used as ancillary input in modelling applications (e.g., biogeochemical models for Primary Production modelling; crop yield models). Additionally, MODIS data are often used by biologists/zoologists as ancillary data to monitor/model migratory patterns.

You can find some good introductory material concerning MODIS and its main applications here and here

Is this information sufficient ? Otherwise, I'll be happy to provide further details.

[maelle]

I forgot one question! :see_no_evil: is there any overlapping of data retrieved by your package & https://github.com/MatMatt/MODIS ?

I had started working on https://github.com/maelle/laads but it's for atmosphere, not land, products.

[maelle]

I also wanted to ask about overlap with other "MODIS" packages (I know names can be misleading since MODIS covers a lot of different data sources) such as https://github.com/seantuck12/MODISTools, MODIS mentioned above, and other ones you might have heard of.

[maelle]

See also rts::ModisDownload (and sorry for the chaos of this overlap question)

[lbusett]

• MODIStsp and MODIS have substantial overlaps, since they are both meant to provide access and preprocessing to MODIS products. Two aspects that in my opinion differentiate MODIStsp are its user-friendliness (I think that the MODIStsp Graphical User Interface is very helpful, in particular for less skilled "R" users, though I am clearly a bit biased on the topic), and its ability to allow on-the-fly creation of time series of standard/user provided Spectral Indexes (often used for time series analysis) and of MODIS quality indicators. On the other hand, MODIS provides some additional post-processing functionality (e.g., smoothing), which is something I'm planning to add in the near future.

• MODIStools is a very nice package, but it provides somewhat limited functionality. It is based on the aforementioned ORNL DAAC webservice (https://modis.ornl.gov/data/modis_webservice.html), and therefore provides access only to some MODIS products. Additionally, it is meant to allow access to data concerning a given set of points and their surroundings, while both MODIStsp and MODIS are meant to provide downloading capabilitites to the "full" MODIS raster data (or subsets of those, although the full HDFs need always to be downloaded).

• rts::ModisDownload is again overlapping, but its functionalities are more limited than either MODIStsp and MODIS. (Actually, an early version of ModisDownload is what got me started in developing the package - proper acknwoledgement is given in MODIStsp where needed)

For reference , section 1 of our paper on CAGEO - which you can download here for free - provides a short comparison of the different tools currently available for accessing MODIS data (both "R" based or not). It's a bit old, but I think that the current situation is similar.

[maelle]

Thanks for all your input for the editors! :-)

[lbusett]

You're welcome.

Thanks for your interest and very prompt reply !

[maelle]

@lbusett all editors agree that this package would be a good fit, we're looking forward to your submission! :smile:

A few notes:

• Please submit the package when it is in a stable state, i.e. when you're not planning any big change. This way the reviewers can comment on the package without its changing at the same time. The reviews might bring small/big changes, they'll provide useful feedback in any case.

• If you have any question regarding rOpenSci guidelines or something else during further package development don't hesitate to ask questions on rOpenSci forum or even via this thread if that's easier for you.

• I'd be in favor of mentioning the other MODIS packages/functions somewhere in the package documentation.

[lbusett]

@maelle Great, thanks !

I'm actually planning a new MODIStsp release today or tomorrow, and then I'll be able to start working on the submission. It will probably take some time, since I'll have to do some (long due) changes in the package, in particular to split-up and simplify a couple of really large functions.

By the way: when I'll be ready to submit, do I have to use this thread or open a new one ?

[maelle]

No problem, take as much time as you need!

You'll have to open a new thread with the submission template where you'll partly fill the same info (e.g. similar packages, applications) but you can refer to this thread at the bottom of the template to link the pre-submission and submission issues.