| DATA_SET_DESCRIPTION |
Data Set Overview
=================
This data set contains the Peter Thomas shape models for small
solar system bodies, as well as image mosaics constructed from
these models. These shape models are based on optical data and
are distinct from the shape models based on radar observations
which are included in a separate data set, EAR-A-5-DDR-
RADARSHAPE-MODELS-V1.0. The current version of this data set
contains the following.
243 Ida: Shape model, image mosaic, and a list of Galileo
SSI images used to construct the image mosaic
951 Gaspra: Shape model, image mosaic, and a list of Galileo
SSI images used to construct the image mosaic
253 Mathilde: Shape model and a list of NEAR MSI images used
to produce the shape model.
4 Vesta: Shape model and a list of HST images used to
produce the shape model.
M1 Phobos: Shape model, image mosaic and a list of Viking
Orbiter images use to construct the image mosaic
M2 Deimos: Shape model, image mosaic and a list of Viking
Orbiter images use to construct the image mosaic
S7 Hyperion: Shape model, image mosaic and a list of Voyager
2 Narrow Angle images use to construct the image
mosaic
S10 Janus: Shape model and list of Voyager 1 and 2 images
used to derive the model (image mosaic not yet
completed)
S11 Epimetheus: Shape model and list of Voyager 1 and 2 images
used to derive the model (image mosaic not yet
completed)
Parameters
==========
The shape models consist of a grid of body-centered latitude and
longitude with a diameter listed for each grid point. Details
of mapping and production of each model are given in the PDS
label for the shape model file, and further details are given in
the relevant published papers.
Davies, M.E., V.K. Abalakin, A. Brahic, M. Bursa, B.H. Chovitz,
J.H. Lieske, P.K. Seidelmann, A.T. Sinclair, and I.S. Tiuflin
1992. Report of the IAU/IAG/COSPAR Working Group on Cartographic
Coordinates and Rotational Elements of the Planets and
Satellites - 1991. Celestial Mechanics and Dynamical Astronomy,
53, no. 4, 377-397. [DAVIESETAL1992]
Simonelli, D.P., P.C. Thomas, B.T. Carcich, and J. Veverka 1993.
Generation and use of numerical shape models for irregular solar
system objects. Icarus, 103, 49-61. [SIMONELLIETAL1993]
Thomas, P.C. 1993. Gravity, tides, and topography on small
satellites and asteroids. Icarus 105, 326-344. [THOMAS1993]
Duxbury, T.C., and J.D. Callahan 1989. Phobos and Deimos
control networks. Icarus 77, 275-286. [DUXBURY&CALLAHAN1989]
Duxbury, T.C., J.D. Callahan, and A.C. Ocampo 1984. Phobos:
Close encounter imaging from the Viking Orbiters. NASA
reference publication 1109. [DUXBURYETAL1984]
Davies, M.E., T.R. Colvin, M.J.S. Belton, J. Veverka, and P.
Thomas 1994. The direction of the north pole and the control
network of asteroid 951 Gaspra. Icarus 107, 18-22.
[DAVIESETAL1994A]
Davies, M.E., T.R. Colvin, M.J.S. Belton, J. Veverka, and P.
Thomas 1996. The direction of the north pole and the control
network of asteroid 243 Ida. Icarus 120, 33-37.
[DAVIESETAL1996]
Thomas, P.C., J. Veverka, D. Simonelli, P. Helfenstein, B.
Carcich, M.J.S. Belton, M.E. Davies, and C. Chapman 1994. The
shape of Gaspra. Icarus 107, 25-36. [THOMASETAL1994]
Thomas, P.C., M.J.S. Belton, B. Carcich, C. R. Chapman, M.E.
Davies, R. Sullivan, and J. Veverka 1996. The shape of Ida.
Icarus 120, 20-32. [THOMASETAL1996]
Thomas, P.C., G.J. Black, and P.D. Nicholson 1995. Hyperion:
Rotation, shape, and geology from Voyager images. Icarus 117,
128-148. [THOMASETAL1995]
Yoder, C.F., S.P. Synnott, and H. Salo 1989. Orbits and masses
of Saturn's co-orbiting satellites Janus and Epimetheus.
Astron. J. 98, 1875-1889. [YODERETAL1989]
Thomas, P. 1989. The shapes of small satellites. Icarus 77,
248-274. [THOMAS1989]
Thomas, P.C., R.P. Binzel, M.J. Gaffey, B.H. Zellner,
A.D. Storrs, and E. Wells 1997. Vesta: Spin pole, size, and
shape from HST images. Icarus 128, 88-94. [THOMASETAL1997]
Thomas, P.C., J. Veverka, J.F. Bell III, B.E. Clark, B. Carcich,
J. Joseph, M. Robinson, L.A. McFadden, M.C. Malin, C.R. Chapman,
W. Merline, and S. Murchie 1999. Mathilde: Size, shape, and
geology. Icarus 140, 17-27. [THOMASETAL1999]
Update History
==============
This data set was first reviewed and archived in 1997. It is
now being updated to include two new shape models which have
become available, those of the asteroids 253 Mathilde and 4
Vesta.
In February 2002 a critical look was taken at the labels of
these files in order to fill in information previously left
blank. The following changes were made:
o INSTRUMENT and INSTRUMENT_HOST were provided in all cases.
o START_TIME and STOP_TIME were provided as accurately as
they could be determined from data elsewhere in the PDS
archives. [ Note that the START_TIME and STOP_TIME for the
entire data set has been left as 'N/A,' since the concept is
not really relevant to the shape model content as a whole.]
o The AXIS_ORDER_TYPE keyword was added to the IMAGE object
in FITS file PDS labels with a value of 'FIRST ORDER FASTEST'.
This is the appropriate order for FITS files (but not the PDS
default).
o A few minor typographical errors in description fields were
corrected.
o The 'mathilde.lbl' file, which was inadvertently left
incomplete and contained several syntactical errors, was
completed and the format verified.
o The file names and TARGET_NAME values corresponding to
asteroids were changed to the (new) standard format
_.
|
.png)
.png)
