urn:nasa:pds:cassini_vims_saturn:data_raw:ring-geometry 1.0 1.11.0.0 Product_Metadata_Supplemental M. R. Showalter, R. S. French, M. W. Evans, M. K. Gordon, and M. S. Tiscareno 2020 metadata This table describes the ring intercept geometry within the field of view of Cassini VIMS image cubes. 2020-03-28 1.0 Initial delivery ring-geometry.tab 2020-03-29T17:52:41 482852183 655159 c0779927ae560cd4d0bffb224f5de068 This table describes the ring intercept geometry within the field of view of Cassini VIMS image cubes. 0 655177 This index describes the ring intercept geometry of the field of view of Cassini VIMS cubes. The table contains zero to two rows for each data file found in the data set. The file contains one row if the VIS channel is enabled and one if the IR channel is enabled. Occasionally, SPICE pointing information is unavailable for the time at which a cube was exposed. When this situation occurs, no rows have been added to the file. This geometry information has been constructed by sampling every VIMS spatial pixel in the associated data file. For each sampled pixel, a variety of geometric quantitities have been calculated, and the minimum and maximum values of each quantity have been tabulated. Note that, for angular quantities that cycle from 360 degrees to zero, the tabulated minimum can be numerically greater than the maximum. If the ring plane does not fall within the field of view, values of the NULL_CONSTANT appear in the table. Regions of the ring plane that are obscured by Saturn or by a targeted moon are excluded from the tabulation. Note: This file was obtained from the PDS Ring-Moon Systems Node at this URL: https://pds-rings.seti.org/viewmaster/metadata/COVIMS_0xxx/COVIMS_0999/COVIMS_0999_ring_summary.tab It was downloaded on July 30, 2019. Two additional, leading columns, containing the image LID and PDS4 raw image file path, have been pre-pended to each record and the remainder of each record has been modified slightly. Carriage-Return Line-Feed 61 0 737 Image LID 1 1 ASCII_LID 56 The LID for this image cube. File Specification 2 58 ASCII_File_Specification_Name 32 The directory path to the latest version of the associated raw image file. Channel 3 91 ASCII_String 3 The VIMS instrument channel to which this row of metadata applies, IR or VIS. VOLUME_ID 4 96 ASCII_String 11 The PDS3 volume ID provides a unique identifier for a PDS data volume. FILE_SPECIFICATION_NAME 5 110 ASCII_File_Specification_Name 57 The PDS3 file specification name provides the full name of a file, including a path name, relative to the root directory of the PDS volume. MINIMUM_RIGHT_ASCENSION 6 169 ASCII_Real 10 deg This is the minimum value for J2000 right ascension within the field of view sampled by this observation. For fields of view that cross 360 degrees, the tabulated minimum value will be greater than the maximum. -999. 360. 0. MAXIMUM_RIGHT_ASCENSION 7 180 ASCII_Real 10 deg This is the maximum value for J2000 right ascension within the field of view sampled by this observation. For fields of view that cross 360 degrees, the tabulated minimum value will be greater than the maximum. -999. 360. 0. MINIMUM_DECLINATION 8 191 ASCII_Real 10 deg This is the minimum value for J2000 declination within the field of view sampled by the observation. -999. 90. -90. MAXIMUM_DECLINATION 9 202 ASCII_Real 10 deg This is the maximum value for J2000 declination within the field of view sampled by the observation. -999. 90. -90. MINIMUM_RING_RADIUS 10 213 ASCII_Real 12 km Ring radius is the distance from the center of the planet to the point where a line of sight intercepts the ring plane. Ring intercept points that are obscured by the planet or a moon within the observed field of view are ignored. For observations capturing reflected sunlight (i.e., with wavelengths in the visual or near-infrared), ring intercept points that are shadowed by the planet are also ignored. This column tabulates the minimum value of ring radius within the field of view of the observation. -999. MAXIMUM_RING_RADIUS 11 226 ASCII_Real 12 km Ring radius is the distance from the center of the planet to the point where a line of sight intercepts the ring plane. Ring intercept points that are obscured by the planet or a moon within the observed field of view are ignored. For observations capturing reflected sunlight (i.e., with wavelengths in the visual or near-infrared), ring intercept points that are shadowed by the planet are also ignored. This column tabulates the maximum value of ring radius within the field of view of the observation. -999. FINEST_RING_INTERCEPT_RESOLUTION 12 239 ASCII_Real 10 km Ring intercept resolution is the size of one edge of a pixel at the distance of the ring intercept point. If the pixel shape is not square, it is defined by the smaller of the two edges. Unlike the quantity 'radial resolution', these values are not projected into the ring plane. Ring intercept points that are obscured by the planet or a moon within the observed field of view are ignored. For observations capturing reflected sunlight (i.e., with wavelengths in the visual or near-infrared), ring intercept points that are shadowed by the planet are also ignored. This column tabulates the minimum (finest) value of ring intercept resolution within the field of view of the observation. -999. COARSEST_RING_INTERCEPT_RESOLUTION 13 250 ASCII_Real 10 km Ring intercept resolution is the size of one edge of a pixel at the distance of the ring intercept point. If the pixel shape is not square, it is defined by the larger of the two edges. Unlike the quantity 'radial resolution', these values are not projected into the ring plane. Ring intercept points that are obscured by the planet or a moon within the observed field of view are ignored. For observations capturing reflected sunlight (i.e., with wavelengths in the visual or near-infrared), ring intercept points that are shadowed by the planet are also ignored. This column tabulates the maximum (coarsest) value of ring intercept resolution within the field of view of the observation. -999. FINEST_RADIAL_RESOLUTION 14 261 ASCII_Real 10 km Radial resolution is related to the gradient of the ring intercept radius. It is equal to the largest change in the radius resulting from a one-pixel shift of the line of sight. In practice, it defines the approximate size of the narrowest ring feature that can be resolved. Ring intercept points that are obscured by the planet or a moon within the observed field of view are ignored. For observations capturing reflected sunlight (i.e., with wavelengths in the visual or near-infrared), ring intercept points that are shadowed by the planet are also ignored. This column tabulates the minimum (finest) value of radial resolution within the field of view of the observation. -999. COARSEST_RADIAL_RESOLUTION 15 272 ASCII_Real 10 km Radial resolution is the gradient of the gradient of the ring intercept radius. It is equal to the largest change in the radius resulting from a one-pixel shift of the line of sight. In practice, it defines the approximate size of the narrowest ring feature that can be resolved. Ring intercept points that are obscured by the planet or a moon within the observed field of view are ignored. For observations capturing reflected sunlight (i.e., with wavelengths in the visual or near-infrared), ring intercept points that are shadowed by the planet are also ignored. This column tabulates the maximum (coarsest) value of radial resolution within the field of view of the observation. -999. MINIMUM_RING_DISTANCE 16 283 ASCII_Real 12 km Ring distance equals the separation between the observer and the point where a line of sight intercepts the ring plane. Ring intercept points that are obscured by the planet or a moon are ignored. For observations capturing reflected sunlight (i.e., with wavelengths in the visual or near-infrared), ring intercept points that are shadowed by the planet are also ignored. This column tabulates the minimum value of ring distance within the field of view of the observation. -999. MAXIMUM_RING_DISTANCE 17 296 ASCII_Real 12 km Ring distance equals the separation between the observer and the point where a line of sight intercepts the ring plane. Ring intercept points that are obscured by the planet or a moon within the observed field of view are ignored. For observations capturing reflected sunlight (i.e., with wavelengths in the visual or near-infrared), ring intercept points that are shadowed by the planet are also ignored. This column tabulates the maximum value of ring distance within the field of view of the observation. -999. MINIMUM_RING_LONGITUDE 18 309 ASCII_Real 8 deg Ring longitude specifies the inertial longitude of the ring plane intercept point. Longitudes increase in the prograde direction. Values are defined by a broken angle from the J2000 First Point of Aries (right ascension = 0), along the J2000 x-y plane to the ascending node of the ring system's invariable plane, and then along the ring plane. Ring intercept points that are obscured by the planet or a moon within the observed field of view are ignored. For observations capturing reflected sunlight (i.e., with wavelengths in the visual or near-infrared), ring intercept points that are shadowed by the planet are also ignored. This column tabulates the minimum value of ring longitude within the field of view of the observation. For fields of view that cross the prime meridian, the tabulated minimum value will be greater than the maximum. -999. 360. 0. MAXIMUM_RING_LONGITUDE 19 318 ASCII_Real 8 deg Ring longitude specifies the inertial longitude of the ring plane intercept point. Longitudes increase in the prograde direction. Values are defined by a broken angle from the J2000 First Point of Aries (right ascension = 0), along the J2000 x-y plane to the ascending node of the ring system's invariable plane, and then along the ring plane. Ring intercept points that are obscured by the planet or a moon within the observed field of view are ignored. For observations capturing reflected sunlight (i.e., with wavelengths in the visual or near-infrared), ring intercept points that are shadowed by the planet are also ignored. This column tabulates the maximum value of ring longitude within the field of view of the observation. For fields of view that cross the prime meridian, the tabulated minimum value will be greater than the maximum. -999. 360. 0. MINIMUM_SOLAR_HOUR_ANGLE 20 327 ASCII_Real 8 deg Solar hour angle specifies the longitude of the ring plane intercept point relative to the anti-solar direction. At 90 degrees, the ring particles are moving toward the Sun, whereas at 270 degrees they are moving away. Ring intercept points that are obscured by the planet or a moon within the observed field of view are ignored. However, ring intercept points that are shadowed by the planet are not ignored. This column tabulates the minimum value of solar hour angle within the field of view of the observation. For fields of view that cross the midnight meridian, the tabulated minimum value will be greater than the maximum. -999. 360. 0. MAXIMUM_SOLAR_HOUR_ANGLE 21 336 ASCII_Real 8 deg Solar hour angle specifies the longitude of the ring plane intercept point relative to the anti-solar direction. At 90 degrees, the ring particles are moving toward the Sun, whereas at 270 degrees they are moving away. Ring intercept points that are obscured by the planet or a moon within the observed field of view are ignored. However, ring intercept points that are shadowed by the planet are not ignored. This column tabulates the maximum value of solar hour angle within the field of view of the observation. For fields of view that cross the midnight meridian, the tabulated minimum value will be greater than the maximum. -999. 360. 0. MINIMUM_RING_LONGITUDE_WRT_OBSERVER 22 345 ASCII_Real 8 deg This alternative definition of ring longitude is measured relative to the direction toward the observer. Values increase in the prograde direction. Unlike other ring longitudes, this quantity ranges from -180 to 180 degrees instead of 0 to 360 degrees. Ring intercept points that are obscured by the planet or a moon within the observed field of view are ignored. For observations capturing reflected sunlight (i.e., with wavelengths in the visual or near-infrared), ring intercept points that are shadowed by the planet are also ignored. This column tabulates the minimum value of the this ring longitude within the field of view of the observation. -999. 180. -180. MAXIMUM_RING_LONGITUDE_WRT_OBSERVER 23 354 ASCII_Real 8 deg This alternative definition of ring longitude is measured relative to the direction toward the observer. Values increase in the prograde direction. Unlike other ring longitudes, this quantity ranges from -180 to 180 degrees instead of 0 to 360 degrees. Ring intercept points that are obscured by the planet or a moon within the observed field of view are ignored. For observations capturing reflected sunlight (i.e., with wavelengths in the visual or near-infrared), ring intercept points that are shadowed by the planet are also ignored. This column tabulates the maximum value of this ring longitude within the field of view of the observation. -999. 180. -180. MINIMUM_RING_AZIMUTH 24 363 ASCII_Real 8 deg Ring azimuth is the angle measured at a point in the ring plane, starting from the direction of a photon heading to the observer, and ending at the direction of a local radial vector. This angle is projected into the ring plane and measured in the prograde direction. As seen from the observer, it equals 90 degrees along the right ansa and 270 degrees along the left ansa. Note that this quantity differs from ring longitudes for viewpoints relatively close to the rings, because angles are measured at the ring intercept point rather than at the center of the planet. Ring intercept points that are obscured by the planet or a moon within the observed field of view are ignored. For observations capturing reflected sunlight (i.e., with wavelengths in the visual or near-infrared), ring intercept points that are shadowed by the planet are also ignored. This column tabulates the minimum value of ring azimuth within the field of view of the observation. For fields of view that cross 360 degrees, the tabulated minimum value will be greater than the maximum. -999. 360. 0. MAXIMUM_RING_AZIMUTH 25 372 ASCII_Real 8 deg Ring azimuth is the angle measured at a point in the ring plane, starting from the direction of a photon heading to the observer, and ending at the direction of a local radial vector. This angle is projected into the ring plane and measured in the prograde direction. As seen from the observer, it equals 90 degrees along the right ansa and 270 degrees along the left ansa. Note that this quantity differs from ring longitudes for viewpoints relatively close to the rings, because angles are measured at the ring intercept point rather than at the center of the planet. Ring intercept points that are obscured by the planet or a moon within the observed field of view are ignored. For observations capturing reflected sunlight (i.e., with wavelengths in the visual or near-infrared), ring intercept points that are shadowed by the planet are also ignored. This column tabulates the maximum value of ring azimuth within the field of view of the observation. For fields of view that cross 360 degrees, the tabulated minimum value will be greater than the maximum. -999. 360. 0. MINIMUM_RING_PHASE_ANGLE 26 381 ASCII_Real 8 deg Ring phase angle is the angle, measured at the ring intercept point, between the direction of the incoming photon from the Sun and the direction of the outgoing photon to the observer. Ring intercept points that are obscured by the planet or a moon within the observed field of view are ignored. For observations capturing reflected sunlight (i.e., with wavelengths in the visual or near-infrared), ring intercept points that are shadowed by the planet are also ignored. This column tabulates the minimum value of ring phase angle within the field of view of the observation. -999. 180. 0. MAXIMUM_RING_PHASE_ANGLE 27 390 ASCII_Real 8 deg Ring phase angle is the angle, measured at the ring intercept point, between the direction of the incoming photon from the Sun and the direction of the outgoing photon to the observer. Ring intercept points that are obscured by the planet or a moon within the observed field of view are ignored. For observations capturing reflected sunlight (i.e., with wavelengths in the visual or near-infrared), ring intercept points that are shadowed by the planet are also ignored. This column tabulates the maximum value of ring phase angle within the field of view of the observation. -999. 180. 0. MINIMUM_RING_INCIDENCE_ANGLE 28 399 ASCII_Real 8 deg Ring incidence angle is the angle, measured at the ring intercept point, between the local surface normal vector on the sunlit side of the ring plane, to the direction of the incoming photon from the Sun. Note that it never exceeds 90 degrees. Ring intercept points that are obscured by the planet or a moon within the observed field of view are ignored. For observations capturing reflected sunlight (i.e., with wavelengths in the visual or near-infrared), ring intercept points that are shadowed by the planet are also ignored. This column tabulates the minimum value of ring incidence angle within the field of view of the observation. -999. 90. 0. MAXIMUM_RING_INCIDENCE_ANGLE 29 408 ASCII_Real 8 deg Ring incidence angle is the angle, measured at the ring intercept point, between the local surface normal vector on the sunlit side of the ring plane, to the direction of the incoming photon from the Sun. Note that it never exceeds 90 degrees. Ring intercept points that are obscured by the planet or a moon within the observed field of view are ignored. For observations capturing reflected sunlight (i.e., with wavelengths in the visual or near-infrared), ring intercept points that are shadowed by the planet are also ignored. This column tabulates the maximum value of ring incidence angle within the field of view of the observation. -999. 90. 0. MINIMUM_NORTH_BASED_INCIDENCE_ANGLE 30 417 ASCII_Real 8 deg North-based ring incidence angle is the angle, measured at the ring intercept point, between the local surface normal vector on the north side of the ring plane, to the direction of the incoming photon from the Sun. It is > 90 degrees when the Sun shines on the south face of the rings. Ring intercept points that are obscured by the planet or a moon within the observed field of view are ignored. For observations capturing reflected sunlight (i.e., with wavelengths in the visual or near-infrared), ring intercept points that are shadowed by the planet are also ignored. This column tabulates the minimum value of the north-based ring incidence angle within the field of view of the observation. -999. 180. 0. MAXIMUM_NORTH_BASED_INCIDENCE_ANGLE 31 426 ASCII_Real 8 deg North-based ring incidence angle is the angle, measured at the ring intercept point, between the local surface normal vector on the north side of the ring plane, to the direction of the incoming photon from the Sun. It is > 90 degrees when the Sun shines on the south face of the rings. Ring intercept points that are obscured by the planet or a moon within the observed field of view are ignored. For observations capturing reflected sunlight (i.e., with wavelengths in the visual or near-infrared), ring intercept points that are shadowed by the planet are also ignored. This column tabulates the maximum value of the north-based ring incidence angle within the field of view of the observation. -999. 180. 0. MINIMUM_RING_EMISSION_ANGLE 32 435 ASCII_Real 8 deg Ring emission angle is the angle, measured at the ring intercept point, between the local surface normal vector on the sunlit side of the ring plane, to the direction of the outgoing photon to the observer. Note that it is less than 90 degrees on the sunlit side of the ring plane, and greater than 90 degrees on the 'dark' side. Ring intercept points that are obscured by the planet or a moon within the observed field of view are ignored. For observations capturing reflected sunlight (i.e., with wavelengths in the visual or near-infrared), ring intercept points that are shadowed by the planet are also ignored. This column tabulates the minimum value of ring emission angle within the field of view of the observation. -999. 180. 0. MAXIMUM_RING_EMISSION_ANGLE 33 444 ASCII_Real 8 deg Ring emission angle is the angle, measured at the ring intercept point, between the local surface normal vector on the sunlit side of the ring plane, to the direction of the outgoing photon to the observer. Note that it is less than 90 degrees on the sunlit side of the ring plane, and greater than 90 degrees on the 'dark' side. Ring intercept points that are obscured by the planet or a moon within the observed field of view are ignored. For observations capturing reflected sunlight (i.e., with wavelengths in the visual or near-infrared), ring intercept points that are shadowed by the planet are also ignored. This column tabulates the maximum value of ring emission angle within the field of view of the observation. -999. 180. 0. MINIMUM_NORTH_BASED_EMISSION_ANGLE 34 453 ASCII_Real 8 deg North-based ring emission angle is the angle, measured at the ring intercept point, between the local surface normal vector on the north side of the ring plane, to the direction of the outgoing photon to the observer. Note that it is < 90 degrees on the north side of the ring plane and > 90 degrees on the south side. Ring intercept points that are obscured by the planet or a moon within the observed field of view are ignored. For observations capturing reflected sunlight (i.e., with wavelengths in the visual or near-infrared), ring intercept points that are shadowed by the planet are also ignored. This column tabulates the minimum value of north-based ring emission angle within the field of view of the observation. -999. 180. 0. MAXIMUM_NORTH_BASED_EMISSION_ANGLE 35 462 ASCII_Real 8 deg North-based ring emission angle is the angle, measured at the ring intercept point, between the local surface normal vector on the north side of the ring plane, to the direction of the outgoing photon to the observer. Note that it is < 90 degrees on the north side of the ring plane and > 90 degrees on the south side. Ring intercept points that are obscured by the planet or a moon within the observed field of view are ignored. For observations capturing reflected sunlight (i.e., with wavelengths in the visual or near-infrared), ring intercept points that are shadowed by the planet are also ignored. This column tabulates the maximum value of north-based ring emission angle within the field of view of the observation. -999. 180. 0. MINIMUM_SOLAR_RING_ELEVATION 36 471 ASCII_Real 8 deg Solar ring elevation is the angle, measured at the ring intercept point, between the ring plane and the direction of the incoming photon from the Sun. The value is positive on the side of the ring plane defined by prograde rotation; note that this is the north side of the ring plane for Jupiter, Saturn and Neptune, but the IAU-defined south side for Uranus. Ring intercept points that are obscured by the planet or a moon within the observed field of view are ignored. For observations capturing reflected sunlight (i.e., with wavelengths in the visual or near-infrared), ring intercept points that are shadowed by the planet are also ignored. This column tabulates the minimum value of solar ring elevation within the field of view of the observation. -999. 90. -90. MAXIMUM_SOLAR_RING_ELEVATION 37 480 ASCII_Real 8 deg Solar ring elevation is the angle, measured at the ring intercept point, between the ring plane and the direction of the incoming photon from the Sun. The value is positive on the side of the ring plane defined by prograde rotation; note that this is the north side of the ring plane for Jupiter, Saturn and Neptune, but the IAU-defined south side for Uranus. Ring intercept points that are obscured by the planet or a moon within the observed field of view are ignored. For observations capturing reflected sunlight (i.e., with wavelengths in the visual or near-infrared), ring intercept points that are shadowed by the planet are also ignored. This column tabulates the maximum value of solar ring elevation within the field of view of the observation. -999. 90. -90. MINIMUM_OBSERVER_RING_ELEVATION 38 489 ASCII_Real 8 deg Observer ring elevation is the angle, measured at the ring intercept point, between the ring plane and the direction of the outgoing photon to the observer. The value is positive on the side of the ring plane defined by prograde rotation; note that this is the north side of the ring plane for Jupiter, Saturn and Neptune, but the IAU-defined south side for Uranus. Ring intercept points that are obscured by the planet or a moon within the observed field of view are ignored. For observations capturing reflected sunlight (i.e., with wavelengths in the visual or near-infrared), ring intercept points that are shadowed by the planet are also ignored. This column tabulates the minimum value of observer ring elevation within the field of view of the observation. -999. 90. -90. MAXIMUM_OBSERVER_RING_ELEVATION 39 498 ASCII_Real 8 deg Observer ring elevation is the angle, measured at the ring intercept point, between the ring plane and the direction of the outgoing photon to the observer. The value is positive on the side of the ring plane defined by prograde rotation; note that this is the north side of the ring plane for Jupiter, Saturn and Neptune, but the IAU-defined south side for Uranus. Ring intercept points that are obscured by the planet or a moon within the observed field of view are ignored. For observations capturing reflected sunlight (i.e., with wavelengths in the visual or near-infrared), ring intercept points that are shadowed by the planet are also ignored. This column tabulates the maximum value of observer ring elevation within the field of view of the observation. -999. 90. -90. MINIMUM_EDGE_ON_RING_RADIUS 40 507 ASCII_Real 12 km Edge-on ring radius is the distance from the planet's rotation pole to the edge-on intercept point. Edge-on intercept geometry is optimized for describing observations of planetary rings obtained from viewpoints close to the ring plane. It employs cylindrical coordinates (radius, altitude, longitude), where radius values are measured from the ring rotation pole and altitude is normal to the ring plane. The intercept is defined as the point along a line of sight where that line is tangent to a cylinder with a particular radius. Edge-on intercept points that are obscured by the planet or a moon within the observed field of view are ignored. For observations capturing reflected sunlight (i.e., with wavelengths in the visual or near-infrared), intercept points that are shadowed by the planet are also ignored. This column tabulates the minimum value of the edge-on ring radius within the field of view of the observation. -999. MAXIMUM_EDGE_ON_RING_RADIUS 41 520 ASCII_Real 12 km Edge-on ring radius is the distance from the planet's rotation pole to the edge-on intercept point. Edge-on intercept geometry is optimized for describing observations of planetary rings obtained from viewpoints close to the ring plane. It employs cylindrical coordinates (radius, altitude, longitude), where radius values are measured from the ring rotation pole and altitude is normal to the ring plane. The intercept is defined as the point along a line of sight where that line is tangent to a cylinder with a particular radius. Edge-on intercept points that are obscured by the planet or a moon within the observed field of view are ignored. For observations capturing reflected sunlight (i.e., with wavelengths in the visual or near-infrared), intercept points that are shadowed by the planet are also ignored. This column tabulates the maximum value of the edge-on ring radius within the field of view of the observation. -999. MINIMUM_EDGE_ON_RING_ALTITUDE 42 533 ASCII_Real 12 km Edge-on ring altitude is the distance from the ring plane to the edge-on intercept point. The value is positive on the side of the ring plane defined by prograde rotation; note that this is the north side of the ring plane for Jupiter, Saturn and Neptune, but the IAU-defined south side for Uranus. Edge-on intercept geometry is optimized for describing observations of planetary rings obtained from viewpoints close to the ring plane. It employs cylindrical coordinates (radius, altitude, longitude), where radius values are measured from the ring rotation pole and altitude is normal to the ring plane. The intercept is defined as the point along a line of sight where that line is tangent to a cylinder with a particular radius. Edge-on intercept points that are obscured by the planet or a moon within the observed field of view are ignored. For observations capturing reflected sunlight (i.e., with wavelengths in the visual or near-infrared), intercept points that are shadowed by the planet are also ignored. This column tabulates the minimum value of the edge-on ring altitude within the field of view of the observation. -9990000000. MAXIMUM_EDGE_ON_RING_ALTITUDE 43 546 ASCII_Real 12 km Edge-on ring altitude is the distance from the ring plane to the edge-on intercept point. The value is positive on the side of the ring plane defined by prograde rotation; note that this is the north side of the ring plane for Jupiter, Saturn and Neptune, but the IAU-defined south side for Uranus. Edge-on intercept geometry is optimized for describing observations of planetary rings obtained from viewpoints close to the ring plane. It employs cylindrical coordinates (radius, altitude, longitude), where radius values are measured from the ring rotation pole and altitude is normal to the ring plane. The intercept is defined as the point along a line of sight where that line is tangent to a cylinder with a particular radius. Edge-on intercept points that are obscured by the planet or a moon within the observed field of view are ignored. For observations capturing reflected sunlight (i.e., with wavelengths in the visual or near-infrared), intercept points that are shadowed by the planet are also ignored. This column tabulates the maximum value of the edge-on ring altitude within the field of view of the observation. -9990000000. FINEST_EDGE_ON_RADIAL_RESOLUTION 44 559 ASCII_Real 10 km Edge-on radial resolution is the gradient of the edge-on ring radius. It is equal to the largest change in the radius resulting from a one-pixel shift of the line of sight. In practice, it defines the approximate size of the narrowest ring feature that can be resolved. Edge-on intercept geometry is optimized for describing observations of planetary rings obtained from viewpoints close to the ring plane. It employs cylindrical coordinates (radius, altitude, longitude), where radius values are measured from the ring rotation pole and altitude is normal to the ring plane. The intercept is defined as the point along a line of sight where that line is tangent to a cylinder with a particular radius. Edge-on intercept points that are obscured by the planet or a moon within the observed field of view are ignored. For observations capturing reflected sunlight (i.e., with wavelengths in the visual or near-infrared), intercept points that are shadowed by the planet are also ignored. This column tabulates the minimum value of the edge-on radial resolution within the field of view of the observation. -999. COARSEST_EDGE_ON_RADIAL_RESOLUTION 45 570 ASCII_Real 10 km Edge-on radial resolution is the gradient of the edge-on ring radius. It is equal to the largest change in the radius resulting from a one-pixel shift of the line of sight. In practice, it defines the approximate size of the narrowest ring feature that can be resolved. Edge-on intercept geometry is optimized for describing observations of planetary rings obtained from viewpoints close to the ring plane. It employs cylindrical coordinates (radius, altitude, longitude), where radius values are measured from the ring rotation pole and altitude is normal to the ring plane. The intercept is defined as the point along a line of sight where that line is tangent to a cylinder with a particular radius. Edge-on intercept points that are obscured by the planet or a moon within the observed field of view are ignored. For observations capturing reflected sunlight (i.e., with wavelengths in the visual or near-infrared), intercept points that are shadowed by the planet are also ignored. This column tabulates the maximum value of the edge-on radial resolution within the field of view of the observation. -999. MINIMUM_EDGE_ON_INTERCEPT_DISTANCE 46 581 ASCII_Real 12 km Edge-on intercept distance is distance from the observer to the edge-on intercept point. Edge-on intercept geometry is optimized for describing observations of planetary rings obtained from viewpoints close to the ring plane. It employs cylindrical coordinates (radius, altitude, longitude), where radius values are measured from the ring rotation pole and altitude is normal to the ring plane. The intercept is defined as the point along a line of sight where that line is tangent to a cylinder with a particular radius. Edge-on intercept points that are obscured by the planet or a moon within the observed field of view are ignored. For observations capturing reflected sunlight (i.e., with wavelengths in the visual or near-infrared), intercept points that are shadowed by the planet are also ignored. This column tabulates the minimum value of the edge-on intercept distance within the field of view of the observation. -999. MAXIMUM_EDGE_ON_INTERCEPT_DISTANCE 47 594 ASCII_Real 12 km Edge-on intercept distance is distance from the observer to the edge-on intercept point. Edge-on intercept geometry is optimized for describing observations of planetary rings obtained from viewpoints close to the ring plane. It employs cylindrical coordinates (radius, altitude, longitude), where radius values are measured from the ring rotation pole and altitude is normal to the ring plane. The intercept is defined as the point along a line of sight where that line is tangent to a cylinder with a particular radius. Edge-on intercept points that are obscured by the planet or a moon within the observed field of view are ignored. For observations capturing reflected sunlight (i.e., with wavelengths in the visual or near-infrared), intercept points that are shadowed by the planet are also ignored. This column tabulates the maximum value of the edge-on intercept distance within the field of view of the observation. -999. MINIMUM_EDGE_ON_RING_LONGITUDE 48 607 ASCII_Real 8 deg Edge-on ring longitude is the inertial longitude of the edge-on intercept point. Longitudes increase in the prograde direction. Values are defined by a broken angle from the J2000 First Point of Aries (right ascension = 0), along the J2000 x-y plane to the ascending node of the ring system's invariable plane, and then along the ring plane. Edge-on intercept geometry is optimized for describing observations of planetary rings obtained from viewpoints close to the ring plane. It employs cylindrical coordinates (radius, altitude, longitude), where radius values are measured from the ring rotation pole and altitude is normal to the ring plane. The intercept is defined as the point along a line of sight where that line is tangent to a cylinder with a particular radius. Edge-on intercept points that are obscured by the planet or a moon within the observed field of view are ignored. For observations capturing reflected sunlight (i.e., with wavelengths in the visual or near-infrared), intercept points that are shadowed by the planet are also ignored. This column tabulates the minimum value of the edge-on ring longitude within the field of view of the observation. For fields of view that cross the prime meridian, the tabulated minimum value will be greater than the maximum. -999. 360. 0. MAXIMUM_EDGE_ON_RING_LONGITUDE 49 616 ASCII_Real 8 deg Edge-on ring longitude is the inertial longitude of the edge-on intercept point. Longitudes increase in the prograde direction. Values are defined by a broken angle from the J2000 First Point of Aries (right ascension = 0), along the J2000 x-y plane to the ascending node of the ring system's invariable plane, and then along the ring plane. Edge-on intercept geometry is optimized for describing observations of planetary rings obtained from viewpoints close to the ring plane. It employs cylindrical coordinates (radius, altitude, longitude), where radius values are measured from the ring rotation pole and altitude is normal to the ring plane. The intercept is defined as the point along a line of sight where that line is tangent to a cylinder with a particular radius. Edge-on intercept points that are obscured by the planet or a moon within the observed field of view are ignored. For observations capturing reflected sunlight (i.e., with wavelengths in the visual or near-infrared), intercept points that are shadowed by the planet are also ignored. This column tabulates the maximum value of the edge-on ring longitude within the field of view of the observation. For fields of view that cross the prime meridian, the tabulated minimum value will be greater than the maximum. -999. 360. 0. MINIMUM_EDGE_ON_SOLAR_HOUR_ANGLE 50 625 ASCII_Real 8 deg Edge-on solar hour angle is the longitude of the edge-on intercept point relative to the anti-solar direction. At 90 degrees, the ring particles are moving toward the Sun, whereas at 270 degrees they are moving away. Edge-on intercept geometry is optimized for describing observations of planetary rings obtained from viewpoints close to the ring plane. It employs cylindrical coordinates (radius, altitude, longitude), where radius values are measured from the ring rotation pole and altitude is normal to the ring plane. The intercept is defined as the point along a line of sight where that line is tangent to a cylinder with a particular radius. Edge-on intercept points that are obscured by the planet or a moon within the observed field of view are ignored. For observations capturing reflected sunlight (i.e., with wavelengths in the visual or near-infrared), intercept points that are shadowed by the planet are also ignored. This column tabulates the minimum value of the edge-on solar hour angle within the field of view of the observation. For fields of view that cross the midnight meridian, the tabulated minimum value will be greater than the maximum. -999. 360. 0. MAXIMUM_EDGE_ON_SOLAR_HOUR_ANGLE 51 634 ASCII_Real 8 deg Edge-on solar hour angle is the longitude of the edge-on intercept point relative to the anti-solar direction. At 90 degrees, the ring particles are moving toward the Sun, whereas at 270 degrees they are moving away. Edge-on intercept geometry is optimized for describing observations of planetary rings obtained from viewpoints close to the ring plane. It employs cylindrical coordinates (radius, altitude, longitude), where radius values are measured from the ring rotation pole and altitude is normal to the ring plane. The intercept is defined as the point along a line of sight where that line is tangent to a cylinder with a particular radius. Edge-on intercept points that are obscured by the planet or a moon within the observed field of view are ignored. For observations capturing reflected sunlight (i.e., with wavelengths in the visual or near-infrared), intercept points that are shadowed by the planet are also ignored. This column tabulates the maximum value of the edge-on solar hour angle within the field of view of the observation. For fields of view that cross the midnight meridian, the tabulated minimum value will be greater than the maximum. -999. 360. 0. RING_CENTER_DISTANCE 52 643 ASCII_Real 12 km Distance from the observer to the center of the ring system. This value is defined by the instantaneous geometry at the time of the observation; it is independent of the field of view. -999. SUB_SOLAR_RING_LONGITUDE 53 656 ASCII_Real 8 deg Inertial longitude of the sub-solar point on the ring plane. Longitudes increase in the prograde direction. Values are defined by a broken angle from the J2000 First Point of Aries (right ascension = 0), along the J2000 x-y plane to the ascending node of the ring system's invariable plane, and then along the ring plane. This value is defined by the instantaneous geometry at the time of the observation; it is independent of the field of view. -999. 360. 0. SUB_OBSERVER_RING_LONGITUDE 54 665 ASCII_Real 8 deg Inertial longitude of the sub-observer point on the ring plane. Longitudes increase in the prograde direction. Values are defined by a broken angle from the J2000 First Point of Aries (right ascension = 0), along the J2000 x-y plane to the ascending node of the ring system's invariable plane, and then along the ring plane. This value is defined by the instantaneous geometry at the time of the observation; it is independent of the field of view. -999. 360. 0. RING_CENTER_PHASE_ANGLE 55 674 ASCII_Real 8 deg Phase angle at the center of the ring system. This is the angle between the local direction of in incoming photon from the Sun and the local direction of an outgoing photon to the observer. This value is defined by the instantaneous geometry at the time of the observation; it is independent of the field of view. -999. 180. 0. RING_CENTER_INCIDENCE_ANGLE 56 683 ASCII_Real 8 deg Ring incidence angle at the center of the ring system. This is the angle measured from the local surface normal vector on the sunlit side of the ring plane to the direction of the incoming photon from the Sun. Note that it never exceeds 90 degrees. This value is defined by the instantaneous geometry at the time of the observation; it is independent of the field of view. -999. 90. 0. RING_CENTER_NORTH_BASED_INCIDENCE_ANGLE 57 692 ASCII_Real 8 deg North-based ring incidence angle at the center of the ring system. This is the angle measured from the local surface normal vector on the north side of the ring plane to the direction of the incoming photon from the Sun. It is > 90 degrees when the Sun shines on the south face of the rings. This value is defined by the instantaneous geometry at the time of the observation; it is independent of the field of view. -999. 180. 0. RING_CENTER_EMISSION_ANGLE 58 701 ASCII_Real 8 deg Ring emission angle at the center of the ring system. This is the angle measured from the local surface normal vector on the sunlit side of the ring plane to the direction of the outgoing photon to the observer. It is < 90 degrees on the sunlit side of the ring plane and > 90 degrees on the 'dark' side. This value is defined by the instantaneous geometry at the time of the observation; it is independent of the field of view. -999. 180. 0. RING_CENTER_NORTH_BASED_EMISSION_ANGLE 59 710 ASCII_Real 8 deg North-based ring emission angle at the center of the ring system. This is the angle measured from the local surface normal vector on the north side of the ring plane to the direction of the outgoing photon to the observer. It is < 90 degrees on the north side of the ring plane and > 90 degrees on the south side. This value is defined by the instantaneous geometry at the time of the observation; it is independent of the field of view. -999. 180. 0. SOLAR_RING_OPENING_ANGLE 60 719 ASCII_Real 8 deg Solar ring opening angle at the center of the ring system. This is the angle from the ring plane to the direction of incoming photon from the Sun. It is positive on the north side of the ring plane and negative on the south side. This value is defined by the instantaneous geometry at the time of the observation; it is independent of the field of view. -999. 90. -90. OBSERVER_RING_OPENING_ANGLE 61 728 ASCII_Real 8 deg Observed ring opening angle at the center of the ring system. This is the angle from the ring plane to the direction of outgoing photon to the observer. It is positive on the north side of the ring plane and negative on the south side. This value is defined by the instantaneous geometry at the time of the observation; it is independent of the field of view. -999. 90. -90.