• new_pole

new_pole

Description

This program solves for a user input old and new right ascension (RA), declination (DEC), prime meridian (PM), and rotation rate (OMEGA), and updates the landmark center locations and map frames, and the spacecraft position, camera unit vectors and Sun unit vectors in all relevant files.

Input Files

• DATA/ - directory containing SPICE kernels.

• INIT_LITHOS.TXT - initialization file which contains the parameter PCK, which defines the planetary constants for a variety of objects (such as Bennu or the Sun). This is required for SPICE function calls.

• LMKFILES/ - directory containing .LMK files.

• LMRKLIST.TXT - list of landmarks.

• MAPFILES/ - directory containing MAPFILES.

• NOMINALS/ - directory containing the NOMINALS.

• PICTLIST.TXT - list of pictures.

• SUMFILES/ - directory containing the SUMFILES.

The required directories and files must be in the working directory.

Unlike pole, new_pole does not require POLE.TXT. Instead, you input the pole RA, Dec, PM, OEMGA, via standard input.

NEW_POLE does not correctly account for overlaps, according to Bob (October 2022). To avoid NaNs when running geometry or iterating the LMKs in lithos after running NEW_POLE, you should remove all overlaps from all landmarks before running either program.

Using new_pole

1. Input the old right ascension (deg), declination (deg), prime meridian (deg), and rate of rotation (deg/day).

 enter old RA, DEC, PM, OMEGA
86   -65   89.00000000   2010.48945

2. Input the new right ascension (deg), declination (deg), prime meridian (deg), and rate of rotation (deg/day).

 enter new RA, DEC, PM, OMEGA
86.60062   -65.00002    90.42707  2009.99979311

3. Input a time in UTC.

• Make sure the time is within the span supported by the kernels.

 Input epoch UTC0
2018 NOV 16 13:09:54.824

new_pole:

• Updates the landmark center location (VLM), and map frame (UX, UY, and UZ) in the LMK files;
• Updates the .MAP files;
• Updates the spacecraft position (SCOBJ), camera unit vectors (CX, CY, and CZ), and Sun unit vector (SZ) in the SUMFILES;
• Updates the spacecraft position (SCOBJ), camera unit vectors (CX, CY, and CZ), and Sun unit vector (SZ) in the NOMINALS.

• Outputs the commands required to run GEOMETRY.

Here is a sample output GEOMTERY commands:

 GEOMETRY
 10
 1
 n
 n

new_pole generates a POLE.TXT file in which it records the new RA, DEC, PM, and OMEGA.

Here is a sample POLE.TXT:

    86.60062   -65.00002    90.42707  2009.99979311

(Compiled by DL)

CategoryPrograms