/* -Header_File SpiceDtl.h ( CSPICE DSK tolerance definitions ) -Abstract Define CSPICE DSK tolerance and margin macros. -Disclaimer THIS SOFTWARE AND ANY RELATED MATERIALS WERE CREATED BY THE CALIFORNIA INSTITUTE OF TECHNOLOGY (CALTECH) UNDER A U.S. GOVERNMENT CONTRACT WITH THE NATIONAL AERONAUTICS AND SPACE ADMINISTRATION (NASA). THE SOFTWARE IS TECHNOLOGY AND SOFTWARE PUBLICLY AVAILABLE UNDER U.S. EXPORT LAWS AND IS PROVIDED "AS-IS" TO THE RECIPIENT WITHOUT WARRANTY OF ANY KIND, INCLUDING ANY WARRANTIES OF PERFORMANCE OR MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE OR PURPOSE (AS SET FORTH IN UNITED STATES UCC SECTIONS 2312-2313) OR FOR ANY PURPOSE WHATSOEVER, FOR THE SOFTWARE AND RELATED MATERIALS, HOWEVER USED. IN NO EVENT SHALL CALTECH, ITS JET PROPULSION LABORATORY, OR NASA BE LIABLE FOR ANY DAMAGES AND/OR COSTS, INCLUDING, BUT NOT LIMITED TO, INCIDENTAL OR CONSEQUENTIAL DAMAGES OF ANY KIND, INCLUDING ECONOMIC DAMAGE OR INJURY TO PROPERTY AND LOST PROFITS, REGARDLESS OF WHETHER CALTECH, JPL, OR NASA BE ADVISED, HAVE REASON TO KNOW, OR, IN FACT, SHALL KNOW OF THE POSSIBILITY. RECIPIENT BEARS ALL RISK RELATING TO QUALITY AND PERFORMANCE OF THE SOFTWARE AND ANY RELATED MATERIALS, AND AGREES TO INDEMNIFY CALTECH AND NASA FOR ALL THIRD-PARTY CLAIMS RESULTING FROM THE ACTIONS OF RECIPIENT IN THE USE OF THE SOFTWARE. -Required_Reading DSK -Particulars This file contains declarations of tolerance and margin values used by the DSK subsystem. The values declared in this file are accessible at run time through the routines dskgtl_c {DSK, get tolerance value} dskstl_c {DSK, set tolerance value} -Literature_References None. -Author_and_Institution N.J. Bachman (JPL) -Restrictions It is recommended that the default values defined in this file be changed only by expert SPICE users. -Version -CSPICE Version 1.0.0, 27-FEB-2016 (NJB) */ #ifndef HAVE_SPICE_DSKTOL_H #define HAVE_SPICE_DSKTOL_H /* Parameter declarations ====================== DSK type 2 plate expansion factor --------------------------------- The factor SPICE_DSK_XFRACT is used to slightly expand plates read from DSK type 2 segments in order to perform ray-plate intercept computations. This expansion is performed to prevent rays from passing through a target object without any intersection being detected. Such "false miss" conditions can occur due to round-off errors. Plate expansion is done by computing the difference vectors between a plate's vertices and the plate's centroid, scaling those differences by (1 + SPICE_DSK_XFRACT), then producing new vertices by adding the scaled differences to the centroid. This process doesn't affect the stored DSK data. Plate expansion is also performed when surface points are mapped to plates on which they lie, as is done for illumination angle computations. This parameter is user-adjustable. */ #define SPICE_DSK_XFRACT ( 1.0e-10 ) /* The keyword for setting or retrieving this factor is */ #define SPICE_DSK_KEYXFR 1 /* Greedy segment selection factor ------------------------------- The factor SGREED is used to slightly expand DSK segment boundaries in order to select segments to consider for ray-surface intercept computations. The effect of this factor is to make the multi-segment intercept algorithm consider all segments that are sufficiently close to the ray of interest, even if the ray misses those segments. This expansion is performed to prevent rays from passing through a target object without any intersection being detected. Such "false miss" conditions can occur due to round-off errors. The exact way this parameter is used is dependent on the coordinate system of the segment to which it applies, and the DSK software implementation. This parameter may be changed in a future version of SPICE. */ #define SPICE_DSK_SGREED ( 1.0e-8 ) /* The keyword for setting or retrieving this factor is */ #define SPICE_DSK_KEYSGR ( SPICE_DSK_KEYXFR + 1 ) /* Segment pad margin ------------------ The segment pad margin is a scale factor used to determine when a point resulting from a ray-surface intercept computation, if outside the segment's boundaries, is close enough to the segment to be considered a valid result. This margin is required in order to make DSK segment padding (surface data extending slightly beyond the segment's coordinate boundaries) usable: if a ray intersects the pad surface outside the segment boundaries; the pad is useless if the intercept is automatically rejected. However, an excessively large value for this parameter is detrimental, since a ray-surface intercept solution found "in" a segment will supersede solutions in segments farther from the ray's vertex. Solutions found outside of a segment thus can mask solutions that are closer to the ray's vertex by as much as the value of this margin, when applied to a segment's boundary dimensions. */ #define SPICE_DSK_SGPADM ( 1.0e-10 ) /* The keyword for setting or retrieving this factor is */ #define SPICE_DSK_KEYSPM ( SPICE_DSK_KEYSGR + 1 ) /* Surface-point membership margin ------------------------------- The surface-point membership margin limits the distance between a point and a surface to which the point is considered to belong. The margin is a scale factor applied to the size of the segment containing the surface. This margin is used to map surface points to outward normal vectors at those points. If this margin is set to an excessively small value, routines that make use of the surface-point mapping won't work properly. */ #define SPICE_DSK_PTMEMM ( 1.0e-7 ) /* The keyword for setting or retrieving this factor is */ #define SPICE_DSK_KEYPTM ( SPICE_DSK_KEYSPM + 1 ) /* Angular rounding margin ----------------------- This margin specifies an amount by which angular values may deviate from their proper ranges without a SPICE error condition being signaled. For example, if an input latitude exceeds pi/2 radians by a positive amount less than this margin, the value is treated as though it were pi/2 radians. Units are radians. */ #define SPICE_DSK_ANGMRG ( 1.0e-12 ) /* This parameter is not user-adjustable. The keyword for retrieving this parameter is */ #define SPICE_DSK_KEYAMG ( SPICE_DSK_KEYPTM + 1 ) /* Longitude alias margin ---------------------- This margin specifies an amount by which a longitude value can be outside a given longitude range without being considered eligible for transformation by addition or subtraction of 2*pi radians. A longitude value, when compared to the endpoints of a longitude interval, will be considered to be equal to an endpoint if the value is outside the interval differs from that endpoint by a magnitude less than the alias margin. Units are radians. */ #define SPICE_DSK_LONALI ( 1.0e-12 ) /* This parameter is not user-adjustable. The keyword for retrieving this parameter is */ #define SPICE_DSK_KEYLAL ( SPICE_DSK_KEYAMG + 1 ) #endif /* End of header file SpiceDtl.h */