NEXTSTEP Satellite Tracking

Tripod Engineering is pleased to announce the availability of Rendezvous,
a MAB NEXTSTEP compatible satellite tracking and Space Surveillance tool.

Rendezvous will read standard NASA/NORAD two line element set files and
graphically display the orbit as a ground trace in any of three different
world projections including a NASA Select style globe.  The solar terminator,
earth coverage area, and satellite illumination conditions can be displayed on
the map with the push of a button, providing an easy and intuitive means for
determining if a satellite is visible from your location.  Satellites may be
flown forward or backward simply by changing the time in the clock, or
selecting the day, month, or year in the handy calendar.  The map is
immediately updated to reflect the date and time you've selected.

Ground station and satellite selections are displayed in browsers, and the
engagement geometry between any set of sensors and targets may be viewed by
selection in the browsers.  Detailed plots of the engagement (azimuth,
elevation, and range) can be shown in a separate window.  A display of the
sensor's field of view, including stars, targets, sun, moon, and earth horizon
can be shown with the telescope inspector window, and the orientation of the
sensor can be changed by adjusting the sliders.  The sun and moon are
displayed in the inspector window with their actual apparent size, and solar
eclipses are displayed properly (lunar eclipses will be supported in the next
release).

Telescope boresight tracking supports four different modes.  There is inertial
tracking where the boresight remains fixed in inertial space as the telescope
orbits.  Second is fixed az-el mode in which an azimuth, elevation, and roll
angle are specified in "local horizontal" coordinates.  As the telescope
orbits, the boresight slowly changes to maintain this az/el/roll in its
current instantaneous local horizontal system.  The third and fourth modes are
target tracking modes in which the telescope boresight is locked on to single
targets or the centroid of a cluster of targets selected from a browser.  As
the telescope orbits, its boresight always remains pointed at the target or
centroid.

For the adventurous souls, the element set can be displayed and changed in
nine different coordinate systems.  This allows quick conversion between the
commonly used systems (ECI, ECR, Orbital Elements, etc), and lets the user
perform "what-if" type experiments by changing the values of various
parameters.  For example, if you were responsible for discarding the solar
panel from the Hubble Space Telescope, would you recommend giving it a boost
forward, backward, or to the side?  Each of these scenerios can be explored
quite easily by changing the velocity compenent of the Hubble Telescope state
vector and watching the ensuing trajectory.

A demo copy of Rendezvous is available on sonata.cc.purdue.edu in /pub/next
/submissions and at cs.orst.edu in /pub/next/demos/science.  The Version 1.0
demo is restricted to propagating orbiting objects with a simulated epoch date
prior to June 1, 1994.  Registered versions are, of course, unrestricted.
Rendezvous is being distributed by Alembic Systems - see the Info panel for
information on current pricing and availability.

Howard Cole
Tripod Engineering
hcole@zia.nrcabq.com