Additional vertical datums in S100 discovery metadata S100

Additional vertical datums (in S-100 discovery metadata) S-100 TSM 8 2 -4 March 2021 Raphael Malyankar

Additional vertical datums • S-104 (and/or S-111) will use datums not enumerated in S-100 Ed. 4. 0. 0 Part 4 a. • May want to state EPSG codes for vertical datums in discovery metadata, as allowed in S-100 Edition 5. 0. 0 carrier metadata. • TWCWG will discuss the additions at TWCWG 5 and finalize the list before a final proposal is prepared. Name ITRF 2014 Description International Terrestrial Reference Frame 2014 ITRF 2020 International Terrestrial Reference Frame 2020 ellipsoidal. Height. Gene Ellipsoidal height (generic) ric baltic. Sea. Chart. Datum Baltic Sea Chart Datum 2000 geoid. Generic Geoid (generic) Code Remarks ? ? [determination underway] ? Ellipsoidal height for an ellipsoid not specifically named in the list of datums. 44 ? international. Great. Lak International Great Lakes ? es. Datum 2020 sea. Surface Sea surface ? sea. Bottom Sea bottom ? Geoid not specifically named in the list of datums [determination underway] A two-dimensional (in the horizontal plane) field representing the air-sea interface, with high-frequency fluctuations such as wind waves and swell, but not astronomical tides, filtered out Local sea bottom reference 2

Datatype of vertical. Datum in S-100 discovery metadata (Fig. 4 a-D-4) Current S-100 4. 0. 0 + additional datums Proposed alternative 1 Modify datatype to Open enumeration codelist Proposed alternative 2 Modify datatype to Dictionary codelist Alternative 3: S 100_Dataset. Discovery. Metadata. other. Vertical. Datum: Character. String [0. . 1]. Not being machine-processable, this is not the recommended solution. 3

Encoding of vertical. Datum in discovery metadata XML Current (S-100 4. 0. 0): If enumerated: <S 100 XC: vertical. Datum>mean. Low. Water. Springs </S 100 XC: vertical. Datum> If unenumerated, omit vertical. Datum or encode as empty element with nil. Reason attribute: <S 100 XC: vertical. Datum xsi: nil="true" gco: nil. Reason="other: not enumerated"/> or Not machine <S 100 XC: vertical. Datum xsi: nil="true" gco: nil. Reason="other: ITRF 2014"/> processable! With open enumeration codelist: If enumerated: <S 100 XC: vertical. Datum>mean. Low. Water. Springs</S 100 XC: vertical. Datum> If unenumerated: <S 100 XC: vertical. Datum>other: EPSG 1234</S 100 XC: vertical. Datum> With dictionary codelist: <S 100 XC: vertical. Datum code. List=“urn: mrn: iho: spec: s 100: 5: 0: vdatum” code. List. Value=“mean. Low. Water. Springs” /> Searchable key in the datums dictionary file 4

ISO 19115 codelists dictionary example - for information The S-100 4. 0. 0 schemas package on the S-100 Git. Hub site contains codelist dictionaries for both ISO 19115 -x and S-100 codelists. 5