COLLECTION METADATA FOR THE UCSB SPOT CATALOG

Scope and purpose The UCSB SPOT Catalog is a complete, up-to-date, worldwide metadata database for SPOT/Image remote-sensing imagery. The database is essentially a clone of Sirius except for the handling of incomplete scenes: whereas Sirius contains incomplete scenes which must be manually "shifted" to become complete scenes before purchasing (actually, Sirius allows all scenes to be shifted), the UCSB catalog minimally pre-shifts all incomplete scenes and thus effectively contains complete scenes only. In addition, the UCSB catalog groups scenes that are near-duplicates of each other (e.g., the "same" scene as acquired by different ground stations) and selects only the "best" representative from each group for display, thereby reducing the total number of scenes. The database is updated daily by harvesting Sirius; multiple, staggered harvest passes capture both new scenes and modifications to older scenes. The UCSB catalog helps manage UCSB's local archive of SPOT imagery and supports the UCSB Center for SPOT Imagery's purchase order system.

Total item count 10,221,768 items as of January 10, 2009.

Item types

Type		Count
satellite 1		793,069
satellite 2		4,127,688
satellite 3		421,125
satellite 4		2,780,596
satellite 5		2,099,290
at Iunctus Geomatics		1,324,828
sellable by UCSB		1,221,425
at UCSB		79,855

Spatial (geographic) coverage

Overall spatial coverage

Spatial coverage by item type:

Temporal coverage

Overall temporal coverage

Temporal coverage by item type:

Schema Item-level metadata is derived from the SPOT/Image SCIE format.

Geographic location

Description In general, this standard ADL bucket contains the item's spatial footprint, i.e., an approximation of the subset of the Earth's surface to which the item is relevant.

Metadata mapping For this collection: the minimum bounding rectangle containing the scene corners.

Notes Due to a PostgreSQL/PostGIS limitation, a bounding rectangle that crosses the ±180° meridian is split at the meridian and only the larger piece is retained.

Date

Description In general, this standard ADL bucket contains the item's temporal footprint, i.e., the calendar date or dates to which the item is relevant.

Metadata mapping For this collection: the scene date.

Cloud cover

Description SPOT-specific bucket. Cloud cover percentages are computed for each eighth of the scene, and a scene-wide maximum cloud cover percentage is computed therefrom. Possible values: "cloud-free"; "<10%"; "10-25%"; "25-75%"; and ">75%".

Notes A constraint on this bucket places an upper bound on maximum cloudiness. For example, searching for "<10%" cloudiness returns scenes that are cloud-free as well.

Quality

Description SPOT-specific bucket. Technical quality values are computed for each quarter of the scene, and a scene-wide average quality value is computed therefrom. Possible values: "excellent"; "good"; "poor"; and "unusable".

Notes A constraint on this bucket places a lower bound on quality. For example, searching for "good" scenes returns "excellent" scenes as well.

Satellite

Description SPOT-specific bucket. The satellite number (1-5).

Spectral mode

Description SPOT-specific bucket. The scene's spectral mode, also referred to as the product type. Possible values: "B" (2.5m panchromatic); "A" (5m panchromatic); "J" (10m multispectral); "M" (10m monochromatic); "P" (10m panchromatic); "I" (20m 4-band multispectral); and "X" (20m 3-band multispectral).

Notes Only certain satellite and spectral mode combinations can occur: satellites 1-3 support modes P and X; satellite 4 supports modes M and I; and satellite 5 supports modes B, A, and J.

Physical locations

Description SPOT-specific bucket. The physical location(s) from which the scene can be retrieved (other than France). Possible values: "UCSB" and "Lethbridge".

Notes UCSB is a subset of Lethbridge.

Incidence angle

Description SPOT-specific bucket. The scene incidence angle in degrees.

Notes See SPOT Mirror and Incidence Angles for more information on SPOT viewing geometry. Per Sirius, if the incidence angle is less than or equal in absolute value to 0.36° the scene is considered "vertical"; if less than or equal in absolute value to 7.5°, "quasi-vertical"; and otherwise "oblique".