stac-extensions/card4l

Clarify open SAR questions with CEOS

Closed this issue · 3 comments

m-mohr commented
  • 1.7.9: The CARD4L specification is not clear whether a string representation of a CRS is required or whether an EPSG code would fulfill the requirement already.
  • 4.4: In the CARD4L metadata specification the Gridding Convention details seem to be required although not required in the textual specification.
maawoo commented
  • 1.6.5: Does an Item Link pointing to an orbit data file satisfy the target requirement? The CARD4L metadata specification seems to require state vector objects in the metadata file. If that's actually the case, how can/should at least five state vectors be chosen? Is it okay to select the first few or should they be selected randomly? Furthermore, shouldn't StateVector information be listed in the product instead of source metadata?
  • General: In various places the term Beam ID is used, whereas Swath ID would be more fitting (e.g. Range- and Azimuth Look Bandwidth). Is this a simple mistake or on purpose? The Sentinel-1 Product Specification at least clearly differentiates between both terms.
maawoo commented
  • 2.5: Is it possible that actually just the type of model as a string is required (e.g. WGS84 ellipsoid) and not a float value? If it's actually the latter, then how should this value be sampled? The center of a given scene?
m-mohr commented

General: CEOS is aware of ambiguity and wants to change it. Probably originates from different names in different missions.
1.7.9: EPSG + (WKT2 or PROJJSON)
4.4: CEOS wants to clarify. A free text description is required, with an optional URL or DOI.
1.6.5: A link to the vector file is fine.
2.5: Leave it as it is (regarding EllipsoidalHeight)