The input data comes from optical imagery, mostly Landsat. No other mask is used, unless the outlines authors did.
In Greenland, RGI uses Raster et al (2012). From the paper its not clear what / if they used a mask for the ice sheet proper to help their connectivity level design.
In Antarctica, RGI uses Bliss et al., (2013), which itself relies on the Antarctic Digital Database quite heavily. RGI7 corrected quite some geometries for poor georeferencing.
ADD Consortium (2000) Antarctic Digital Database, Version 3.0, database, manual and bibliography. Scientific Committee on Antarctic Research, Cambridge
Bliss, A., Hock, R., and Cogley, J.G. A new inventory of mountain glaciers and ice caps for the Antarctic periphery. Annals of Glaciology, 54(63):191–199, jul 2013. https://doi.org/10.3189/2013AoG63A377.
Rastner, P., Bolch, T., Mölg, N., Machguth, H., Le Bris, R., and Paul, F.: The first complete inventory of the local glaciers and ice caps on Greenland, The Cryosphere, 6, 1483–1495, https://doi.org/10.5194/tc-6-1483-2012, 2012.
Reason for using this mask
These two papers (2012 and 2013, mind!) decided to do so. Raster suggests a definition, Bliss also contains arguments as to why certain outlines were chosen to be "peripheral" or not.
If you modified the upstream mask, for example, to define and split ‘main’ vs. ‘peripheral’, how and why?
It would be based on a discussion happening here, and together with a clear definition of "main".
Effort required by you if upstream product changed (to a community standard)
If its just about removing outlines, RGI could be amended very quickly. The redefinition of a new standard has, however, quite important implications for downstream products. It's also very likely some sort of mapping would be needed.
If you used internal basins, which product and why?
N.A.
If you subset to a geographical region (Greenland, Antarctica, sub-region, peripheral, individual glacier), how and why
The two original inventories have been slightly adapted for RGI. Importantly, connectivity level 2 is filtered out in Greenland. The main rationale for picking the masks in Bliss and Rastner remains valid.
Overview
Doc: https://www.glims.org/rgi_user_guide
Upstream
The input data comes from optical imagery, mostly Landsat. No other mask is used, unless the outlines authors did.
In Greenland, RGI uses Raster et al (2012). From the paper its not clear what / if they used a mask for the ice sheet proper to help their connectivity level design.
In Antarctica, RGI uses Bliss et al., (2013), which itself relies on the Antarctic Digital Database quite heavily. RGI7 corrected quite some geometries for poor georeferencing.
ADD Consortium (2000) Antarctic Digital Database, Version 3.0, database, manual and bibliography. Scientific Committee on Antarctic Research, Cambridge Bliss, A., Hock, R., and Cogley, J.G. A new inventory of mountain glaciers and ice caps for the Antarctic periphery. Annals of Glaciology, 54(63):191–199, jul 2013. https://doi.org/10.3189/2013AoG63A377. Rastner, P., Bolch, T., Mölg, N., Machguth, H., Le Bris, R., and Paul, F.: The first complete inventory of the local glaciers and ice caps on Greenland, The Cryosphere, 6, 1483–1495, https://doi.org/10.5194/tc-6-1483-2012, 2012.
These two papers (2012 and 2013, mind!) decided to do so. Raster suggests a definition, Bliss also contains arguments as to why certain outlines were chosen to be "peripheral" or not.
It would be based on a discussion happening here, and together with a clear definition of "main".
If its just about removing outlines, RGI could be amended very quickly. The redefinition of a new standard has, however, quite important implications for downstream products. It's also very likely some sort of mapping would be needed.
N.A.
N.A.
Vector
N.A.
WGS84
Downstream
The two original inventories have been slightly adapted for RGI. Importantly, connectivity level 2 is filtered out in Greenland. The main rationale for picking the masks in Bliss and Rastner remains valid.
Other notes