07/03/03 48821 CTB Converted to XML format This relation defines the size, shape, and location of the science instrument apertures. Three fundamental cartesian coordinate systems are used. The first of these systems is the V1-V2-V3 system. It is the three dimensional 'vehicle' coordinate system. The V2-V3 plane defines the 'aperture' plane. The other two fundamental coordinate systems are defined in the aperture plane relative to the V1,V2,V3 frame. The Science Instrument Coordinate System (SICS) is actually a set of coordinate systems; one or more for each science instrument. Coordinates are expressed in arcseconds. Generally there is one SICS defined for each aperture. The Science Aperture Coordinate System (SIAS) is similar to the SICS except the coordinates are expressed in units appropriate for the instrument (i.e. pixels). SIAS is not used in SPSS. This relation does NOT defines the conversion factors needed to transform coordinates expressed in one coordinate system to another. See the SPSS Algorithms document (SE-06-02 Appendix B) for a complete discussion of these transformations and see relation sics_sias_coef for the conversion coefficients. C10 This is the aperture coordinate system ID. It is the name of the aperture coordinate system used to specify the location of the target within the aperture. C17 effective date (YYYY.DDD:HH:MM:SS) before which the data for this aperture must not be used R8 ARCSECONDS This field specifies the V2 coordinate of the center of the aperture. This defines the SICS X direction center (Xo). R8 ARCSECONDS This field specifies the V3 coordinate of the center of the aperture. This defines the SICS Y direction center (Yo). C1 This field specifies the geometric shape of the aperture. The possible choices are 'P', 'C', 'Q', or 'R'. 'P' implies a pickle shape (FGS). 'C' implies a circular shape. 'Q' implies a quadrilateral shape. 'R' implies a rectangular shape. R8 ARCSECONDS This field is only significant for circular or pickle shaped apertures and is defined in the SICS system. For a circular aperture, this is the radius of the aperture measured from the center ('center_v2', 'center_v3'). For a pickle aperture, this is the outer radius. R8 ARCSECONDS This field is only significant for quadrilateral or rectangular shaped apertures and is defined in the SICS system. These apertures are defined in counter- clockwise order from vertex 1 to vertex 4. This is the X coordinate of vertex 1. R8 ARCSECONDS This field is only significant for quadrilateral or rectangular shaped apertures and is defined in the SICS system. These apertures are defined in counter- clockwise order from vertex 1 to vertex 4. This is the Y coordinate of vertex 1. R8 ARCSECONDS This field is only significant for quadrilateral or rectangular shaped apertures and is defined in the SICS system. These apertures are defined in counter- clockwise order from vertex 1 to vertex 4. This is the X coordinate of vertex 2. R8 ARCSECONDS This field is only significant for quadrilateral or rectangular shaped apertures and is defined in the SICS system. These apertures are defined in counter- clockwise order from vertex 1 to vertex 4. This is the Y coordinate of vertex 2. R8 ARCSECONDS This field is only significant for quadrilateral or rectangular shaped apertures and is defined in the SICS system. These apertures are defined in counter- clockwise order from vertex 1 to vertex 4. This is the X coordinate of vertex 3. R8 ARCSECONDS This field is only significant for quadrilateral or rectangular shaped apertures and is defined in the SICS system. These apertures are defined in counter- clockwise order from vertex 1 to vertex 4. This is the Y coordinate of vertex 3. R8 ARCSECONDS This field is only significant for quadrilateral or rectangular shaped apertures and is defined in the SICS system. These apertures are defined in counter- clockwise order from vertex 1 to vertex 4. This is the X coordinate of vertex 4. R8 ARCSECONDS This field is only significant for quadrilateral or rectangular shaped apertures and is defined in the SICS system. These apertures are defined in counter- clockwise order from vertex 1 to vertex 4. This is the Y coordinate of vertex 4. R8 ARCSECONDS This field is only significant for quadrilateral or rectangular shaped apertures and is defined in the V2-V3 system. These apertures are defined in counter-clockwise order from vertex 1 to vertex 4. This is the V2 coordinate of vertex 1. R8 ARCSECONDS This field is only significant for quadrilateral or rectangular shaped apertures and is defined in the V2-V3 system. These apertures are defined in counter-clockwise order from vertex 1 to vertex 4. This is the V3 coordinate of vertex 1. R8 ARCSECONDS This field is only significant for quadrilateral or rectangular shaped apertures and is defined in the V2-V3 system. These apertures are defined in counter-clockwise order from vertex 1 to vertex 4. This is the V2 coordinate of vertex 2. R8 ARCSECONDS This field is only significant for quadrilateral or rectangular shaped apertures and is defined in the V2-V3 system. These apertures are defined in counter-clockwise order from vertex 1 to vertex 4. This is the V3 coordinate of vertex 2. R8 ARCSECONDS This field is only significant for quadrilateral or rectangular shaped apertures and is defined in the V2-V3 system. These apertures are defined in counter-clockwise order from vertex 1 to vertex 4. This is the V2 coordinate of vertex 3. R8 ARCSECONDS This field is only significant for quadrilateral or rectangular shaped apertures and is defined in the V2-V3 system. These apertures are defined in counter-clockwise order from vertex 1 to vertex 4. This is the V3 coordinate of vertex 3. R8 ARCSECONDS This field is only significant for quadrilateral or rectangular shaped apertures and is defined in the V2-V3 system. These apertures are defined in counter-clockwise order from vertex 1 to vertex 4. This is the V2 coordinate of vertex 4. 0 .. 3600 R8 ARCSECONDS This field is only significant for quadrilateral or rectangular shaped apertures and is defined in the V2-V3 system. These apertures are defined in counter-clockwise order from vertex 1 to vertex 4. This is the V3 coordinate of vertex 4. 0 .. 3600 R8 DEGREES This is the aperture reference angle (Ta). It specifies the rotation angle needed to transform from SICS to V2V3 coordinate systems. The angle is measured counter-clockwise as viewed looking along the +V1-axis from the V3-axis to the positive side of the aperture's major axis. 0 .. 360 I2 This field indicates the degree of the polynomial used in the transformation from SIAS to SICS. The maximum value is 5. R8 This is the x coordinate (in pixels) of the origin of the SICS system expressed in the SIAS system. R8 This is the y coordinate (in lines) of the origin of the SICS system expressed in the SIAS system. R8 This is the x coordinate of the origin of the SIAS system expressed in the SICS system. R8 This is the y coordinate of the origin of the SIAS system expressed in the SICS system. APERTURE_DEF Definition of apertures OPUS unique clustered