CODES Dynamical Model

Level One Menu

• Create a new minor planet
  • Specify the name
  • Go to Level Two Menu or

    return to Level One Menu

• Delete an existing minor planet – with a drop-down list of files
  • Select the minor planet
  • Return to Level One Menu
• Edit an existing minor planet – with a drop-down list of files –
  • Select the minor planet
  • Go to Level Two Menu

Level Two Menu

• Designate minor planet as an asteroid or comet
  • Select asteroid or comet
  • Return to Level Two Menu
• Add a new observation
  • Add a new optical observation
    • Enter UTC observation time, ra and dec (with uncertainties)
    • Enter latitude, longitude, altitude
    • Enter the Earth Orientation Parameters and number of leap seconds
    • Return to Level Two Menu
  • Add a new radar delay or doppler observation
    • Enter UTC receiver time, delay or doppler with uncertainty, and transmitter frequency
    • Enter receiver and transmitter latitude, longitude, altitude
    • Enter receiver EOPs and number of leap seconds
    • Return to Level Two Menu
  • Read optical observations from an MPEC/MPCOBS file
    • Save file as mpec.txt
    • Process file
    • Return to Level Two Menu
  • Read optical observations from a NEODyS file
    • Save file as neodys.txt
    • Process file
    • Return to Level Two Menu

• Review/Delete Existing Observations
  • Display observations five at-a-time, with UTC times and radec/delay/doppler
  • If (Next 5) selected,
    • repeat

    If (Delete Checked) selected,

    • delete checked observations
    • repeat

    If (Done) selected,

    • Return To Level Two Menu

• Compute/Evaluate/Propagate the orbit of the minor planet
  • Compute an initial orbit
    1. Select the observations to be used
    2. Select the method to be used (Laplace, Gauss, or conditioned Gauss)
    3. (If conditioned Gauss) Specify semi-major axis
    4. Output orbital elements and state vector with residuals
       • Accept this orbit
         • Return to Level Two Menu
       • Try another method (Return to Step 2)
       • Try a different semi-major axis (conditioned Gauss only) (Return to Step 3)
       • Make new selection of observations to be used (Return to Step 1)
       • Apply differential correction (Return to Step 4)
       • Return to Level Two Menu
  • Compute a best-fit orbit
    • Select whether to use non-gravitational thrust parameters and process
    • Display residuals (observed – computed) five-at-a-time
    • Display absolute visual magnitude, slope parameter, and (asteroid only) radius
    • Display orbital elements
    • Display state vector
    • Return to Level Two Menu
  • Compute residuals
    • Process
    • Display residuals (observed - computed) five-at-a-time
    • Display orbital elements
    • Display state vector
    • Return to Level Two Menu
  • Propogate orbit to a new epoch
    • Specify new epoch time and process
    • Display new epoch time, orbital elements with covariances, and non-gravitational thrust parameters
    • Display new epoch time, state vector with covariances, and non-gravitational thrust parameters
    • Return to Level Two Menu

• Display current orbit
  • Select orbital elements or state vector
  • Display epoch time, orbital elements with covariances, and non-gravitational thrust parameters, or

    Display epoch time, state vector with covariances, and non-gravitational thrust parameters

  • Return to Level Two Menu
• Specify the minor planet’s orbit
  • Specify the state vector
    • Specify epoch time, position and velocity with covariances, and non-gravitational thrust parameters – (default to current, accept changes)
    • Return to Level Two Menu
  • Specify the orbital elements
    • Specify epoch time, orbital elements with covariances, and non-gravitational thrust parameters - (default to current, accept changes)
    • Return to Level Two Menu
• Compare observations to positions of known minor planets
  • Specify two-body or n-body mechanics, limit asteroid search, and process
  • Display candidates, 10-at-a-time
  • Return to Level Two Menu

• Create an optical ephemeris
  • Specify the start and end dates, the interval, geocentric or topocentric (if topocentric, enter latitude, longitude, altitude, and UT1-TAI), and process
  • Output – one entry per page
  • Return to Level Two Menu
• Check for collision or near-miss
  • Select endpoint and process
  • Output- one event per page
  • Return to Level Two Menu
• Specify the number of perturbing bodies for integrator
  • Select from:
    • Planets plus Earth’s Moon
    • Planets, Earth’s Moon, plus Ceres, Pallas, and Vesta
    • Planets, Earth’s Moon, plus all asteroids with reliable mass estimates (235)
    • Planets, Earth’s Moon, plus all available asteroids (300)
  • Return to Level Two Menu
• Specify the minor planet’s radius, absolute visual magnitude, and slope parameter
  • Specify the minor planet’s radius, AND/OR

    Specify the minor planet’s absolute visual magnitude, AND/OR

    Specify the minor planet’s slope parameter

  • (OPTIONAL) Using displayed slope parameter, recalculate absolute visual magnitude and (asteroid only) radius
  • Return to Level Two Menu

• Return to Level One Menu