PDS_VERSION_ID = PDS3 RECORD_TYPE = STREAM LABEL_REVISION_NOTE = " 2015-02-09, Roatsch, Initial image mosaic version; 2015-05-14, S. Joy addressed peer mosaic review liens; 2016-09-01, S. Joy updated for SPG DTM review; 2016-12-20, S. Joy updated post review with info from Marita Waehlisch from DLR" TARGET_NAME = "4 VESTA" INSTRUMENT_HOST_NAME = "DAWN" OBJECT = DATA_SET_MAP_PROJECTION DATA_SET_ID = "DAWN-A-FC2-5-VESTADTMSPG-V1.0" OBJECT = DATA_SET_MAP_PROJECTION_INFO MAP_PROJECTION_TYPE = "SIMPLE CYLINDRICAL" MAP_PROJECTION_DESC = "This simple cylindrical map projection is neither equal-area nor conformal. The meridians and parallels are equidistant straight lines, intersecting at right angles (See Snyder 1987, Ch 12. Equidistant Cylindrical Projection, pp 90-91). In general the transformation from the cartographic coordinates X, Y to line and sample in the PDS image is as follows: sample = INT(SAMPLE_PROJECTION_OFFSET + SAMPLE_LAST_PIXEL + 1 + (lon - CENTER_LONGITUDE)*MAP_RESOLUTION) mod SAMPLE_LAST_PIXEL line = INT (LINE_PROJECTION_OFFSET - lat*MAP_RESOLUTION) +1 The use of a non-standard center longitude definition for Vesta, coupled with the PDS range limitations on longitude, introduces the modulo in the sample equation above. LINE_PROJECTION_OFFSET is the line number minus one on which the map projection origin occurs. The map projection origin is the intersection of the equator and the projection longitude. The value of LINE_PROJECTION_OFFSET is positive for images starting north of the equator and is negative for images starting south of the equator. SAMPLE_PROJECTION_OFFSET is the nearest sample number to the left of the projection longitude. The value of SAMPLE_PROJECTION_OFFSET is positive for images starting to the west of the projection longitude and is negative for images starting to the east of the projection longitude. CENTER_LONGITUDE is the value of the projection longitude, which is the longitude that passes through the center of the projection. MAP_RESOLUTION is measured in pixels/degree. There are four PDS parameters that specify the latitude and longitude boundaries of an image. MAXIMUM_LATITUDE and MINIMUM_LATITUDE specify the latitude boundaries of the image, and EASTERNMOST_LONGITUDE and WESTERNMOST_LONGITUDE specify the longitudinal boundaries of the map. Definitions of other mapping parameters can be found in the PDS Data dictionary. " ROTATIONAL_ELEMENT_DESC = "See ARCHINAL2013" OBJECT = DS_MAP_PROJECTION_REF_INFO REFERENCE_KEY_ID = "ARCHINAL2013" END_OBJECT = DS_MAP_PROJECTION_REF_INFO OBJECT = DS_MAP_PROJECTION_REF_INFO REFERENCE_KEY_ID = "SNYDER1987" END_OBJECT = DS_MAP_PROJECTION_REF_INFO END_OBJECT = DATA_SET_MAP_PROJECTION_INFO /****************************************************************************/ OBJECT = DATA_SET_MAP_PROJECTION_INFO MAP_PROJECTION_TYPE = "STEREOGRAPHIC" MAP_PROJECTION_DESC = "A conformal, azimuthal projection where the central meridian and a particular parallel (if shown) are straight lines. This is a perspective projection for the sphere. All meridians on the polar aspect and the Equator on the equatorial aspect are straight lines. All other meridians and parallels are shown as arcs of circles. Directions from the center of the projection are true (except on ellipsoidal oblique and equatorial aspects). Scale increases away from the center of the projection (See Snyder 1987, Ch 21. Stereographic Projection, pp 154-163). In general the transformation from the cartographic coordinates X, Y to line and sample in the PDS image is as follows: sample = INT( X + SAMPLE_PROJECTION_OFFSET) +1 line = INT(-Y + LINE_PROJECTION_OFFSET) +1 where X = F1(latitude,longitude) Y = F2(latitude,longitude) and F1(latitude,longitude) and F2(latitude,longitude) are the cartographic formulas described detailed in (Snyder 1987) Equations (21-2), (21-3), (21-4), (20-14), (20-15) (20-18), (21-15) of [Synder, 1987] USGS Paper 1395 (pp 157-159) were used. Used keywords and values with respect to map projections follow the PDS3 standard reference whereas a detailed description of the parameter's scope and definition can be found in the PDS dictionary. LINE_PROJECTION_OFFSET/SAMPLE_PROJECTION_OFFSET are the line/sample values minus one onto which the map projection origin falls." ROTATIONAL_ELEMENT_DESC = "See ACTON1996" OBJECT = DS_MAP_PROJECTION_REF_INFO REFERENCE_KEY_ID = "ACTON1996" END_OBJECT = DS_MAP_PROJECTION_REF_INFO OBJECT = DS_MAP_PROJECTION_REF_INFO REFERENCE_KEY_ID = "PDSDD2008" END_OBJECT = DS_MAP_PROJECTION_REF_INFO OBJECT = DS_MAP_PROJECTION_REF_INFO REFERENCE_KEY_ID = "BATSON1990" END_OBJECT = DS_MAP_PROJECTION_REF_INFO OBJECT = DS_MAP_PROJECTION_REF_INFO REFERENCE_KEY_ID = "SNYDER1987" END_OBJECT = DS_MAP_PROJECTION_REF_INFO END_OBJECT = DATA_SET_MAP_PROJECTION_INFO /****************************************************************************/ OBJECT = DATA_SET_MAP_PROJECTION_INFO MAP_PROJECTION_TYPE = "MERCATOR" MAP_PROJECTION_DESC = "A conformal, cylindrical projection where meridians are equally spaced straight lines. Parallels are unequally spaced straight lines, closest near the equator, cutting meridians at right angles. The scale is true along the equator. Poles are at infinity with great distortion of area in polar regions (See Snyder 1987, Ch 7. Mercator Projection, pp 38-47). In general the transformation from the cartographic coordinates X, Y to line and sample in the PDS image is as follows: sample = INT( X + SAMPLE_PROJECTION_OFFSET) +1 line = INT(-Y + LINE_PROJECTION_OFFSET) +1 where X = F1(latitude,longitude) Y = F2(latitude,longitude) and F1(latitude,longitude) and F2(latitude,longitude) are the cartographic formulas described detailed in (Snyder 1987) Equations (7-1), (7-2), (7-2a), (7-4), (7-4a), (7-5) of USGS Paper 1395 (pp 41,44) were used. Keywords and values used with respect to map projections follow the PDS3 standard reference whereas a detailed description of the parameter's scope and definition can be found in the PDS dictionary. LINE_PROJECTION_OFFSET/SAMPLE_PROJECTION_OFFSET are the line/sample values minus one onto which the map projection origin falls." ROTATIONAL_ELEMENT_DESC = "See ACTON1996" OBJECT = DS_MAP_PROJECTION_REF_INFO REFERENCE_KEY_ID = "ACTON1996" END_OBJECT = DS_MAP_PROJECTION_REF_INFO OBJECT = DS_MAP_PROJECTION_REF_INFO REFERENCE_KEY_ID = "ACTON1996" END_OBJECT = DS_MAP_PROJECTION_REF_INFO OBJECT = DS_MAP_PROJECTION_REF_INFO REFERENCE_KEY_ID = "PDSDD2008" END_OBJECT = DS_MAP_PROJECTION_REF_INFO OBJECT = DS_MAP_PROJECTION_REF_INFO REFERENCE_KEY_ID = "BATSON1990" END_OBJECT = DS_MAP_PROJECTION_REF_INFO OBJECT = DS_MAP_PROJECTION_REF_INFO REFERENCE_KEY_ID = "SNYDER1987" END_OBJECT = DS_MAP_PROJECTION_REF_INFO END_OBJECT = DATA_SET_MAP_PROJECTION_INFO /* oBJECT = DATA_SET_MAP_PROJECTION_INFO */ /****************************************************************************/ /* oBJECT = DATA_SET_MAP_PROJECTION */ OBJECT = DATA_SET_MAP_PROJECTION_INFO MAP_PROJECTION_TYPE = "LAMBERT CONFORMAL" MAP_PROJECTION_DESC = "A conformal, conic projection where the parallels are unequally spaced arcs of concentric circles, more closely spaced near the center of the map. Meridians are equally spaced radii of the same circles, thereby cutting parallels at right angles. Scale is true along the standard parallel(s). The pole in the same hemisphere as standard parallel(s) is a point, while the other pole is at infinity (See Snyder 1987, Ch 15. Lambert Conformal Conic Projection, pp 104-110). In general the transformation from the cartographic coordinates X, Y to line and sample in the PDS image is as follows: sample = INT( X + SAMPLE_PROJECTION_OFFSET) +1 line = INT(-Y + LINE_PROJECTION_OFFSET) +1 where X = F1(latitude,longitude) Y = F2(latitude,longitude) and F1(latitude,longitude) and F2(latitude,longitude) are the cartographic formulas described detailed in (Snyder 1987) Equations (14-1), (14-2), (15-1), (14-4), (15-1a), (15-2), (15-3), (15-5), (14-9) (14-10) and (14-11), of USGS Paper 1395 (pp 106,107) were used. Batson et al, 1992 suggest quadrangle schemes that apply a secant cylinder Mercator projection for the equatorial to low latitude areas. As this projection is seldomly implemented in common image data and analysis software, the LAMBERT CONFORMAL projection is used as a substitute. The absolute values of the two standard parallels are set to differ by 0.001 degrees to approximate the secant cylinder Mercator projection. The majority of the map projection descriptions in this document follow the descriptions in Snyder (1987) closely. Used keywords and values with respect to map projections follow the PDS3 standard reference whereas a detailed description of the parameter's scope and definition can be found in the PDS dictionary. LINE_PROJECTION_OFFSET/ SAMPLE_PROJECTION_OFFSET are the line/sample values minus one onto which the map projection origin falls." ROTATIONAL_ELEMENT_DESC = UNK OBJECT = DS_MAP_PROJECTION_REF_INFO REFERENCE_KEY_ID = "PDSDD2008" END_OBJECT = DS_MAP_PROJECTION_REF_INFO OBJECT = DS_MAP_PROJECTION_REF_INFO REFERENCE_KEY_ID = "BATSON1990" END_OBJECT = DS_MAP_PROJECTION_REF_INFO OBJECT = DS_MAP_PROJECTION_REF_INFO REFERENCE_KEY_ID = "SNYDER1987" END_OBJECT = DS_MAP_PROJECTION_REF_INFO END_OBJECT = DATA_SET_MAP_PROJECTION_INFO END_OBJECT = DATA_SET_MAP_PROJECTION END