NOMINALS

Compiled by KD

Description

NOMINALS is a directory that stores the starting solution of an observation that is created from the executable make_sumfiles. Each image has its own NOMINAL file stored in the NOMINALS directory. They have the image name with the suffix .NOM. Furthermore, nominals do not update with the use of SPC (v 4 command in lithos), unlike sumfiles.

All vectors are in body fixed frame.

Nominals include:

Image name
Frame reference
SCOBJ - Location of the S/C (this can be in inertial frame, or body fix position) -- [units km]
SIGMA_VSO - Error in S/C position -- [units km]
Cx, Cy, Cz - Vectors of the camera -- [units rad]
SIGMA_PTG - Error in camera pointing -- [units rad]
There are entries for DYNAMICS that list the previous 2 and follow 2 image relative positions. This is used to condition the S/C position for geometry2

An Example of a Nominal

S595057374F1
   -0.3635326241D+00   -0.9250382113D+00   -0.1102195033D+00   BOD_FRAME
    0.3071334125D+00    0.4756036668D+02   -0.3008768662D+01   SCOBJ
    0.1000000000D+01    0.1000000000D+01    0.1000000000D+01   SIGMA_VSO
    0.9685067274D+00    0.3109628683D-02    0.2489679684D+00   CX
    0.2486662018D+00   -0.6285289007D-01   -0.9665477920D+00   CY
    0.1264275161D-01    0.9980179580D+00   -0.6164670642D-01   CZ
    0.1000000000D-02    0.1000000000D-02    0.1000000000D-02   SIGMA_PTG
END FILE

Another .Nom File Example

Some Possible Improvements (kept from powerpoint notes and can probably be deleted)

TBD Upgrades for the NOMINAL file:
- SIGMA_VSO will specify which coord system
  - View-1 (t,n,R) (capital = exact, principal)
  - View-2 (T,n,r)
  - ISO (x,y,z)