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Date: Wed, 6 Jan 93 05:25:35
From: Space Digest maintainer <digests@isu.isunet.edu>
Reply-To: Space-request@isu.isunet.edu
Subject: Space Digest V16 #006
To: Space Digest Readers
Precedence: bulk
Space Digest Wed, 6 Jan 93 Volume 16 : Issue 006
Today's Topics:
Space FAQ 03/15 - Data Sources
Space FAQ 04/15 - Calculations
Welcome to the Space Digest!! Please send your messages to
"space@isu.isunet.edu", and (un)subscription requests of the form
"Subscribe Space <your name>" to one of these addresses: listserv@uga
(BITNET), rice::boyle (SPAN/NSInet), utadnx::utspan::rice::boyle
(THENET), or space-REQUEST@isu.isunet.edu (Internet).
----------------------------------------------------------------------
Date: 6 Jan 1993 01:51:42 GMT
From: Jon Leech <leech@mahler.cs.unc.edu>
Subject: Space FAQ 03/15 - Data Sources
Newsgroups: sci.astro,sci.space,news.answers
Archive-name: space/data
Last-modified: $Date: 93/01/05 20:24:43 $
ONLINE AND OTHER SOURCES OF IMAGES, DATA, ETC.
INTRODUCTION
A wide variety of images, data, catalogs, information releases, and
other material dealing with space and astronomy may be found on the net.
A few sites offer direct dialup access or remote login access, while the
remainder support some form of file transfer. Many sites are listed as
providing 'anonymous FTP'. This refers to the File Transfer Protocol on
the Internet. Sites not connected to the Internet cannot use FTP
directly, but there are a few automated FTP servers which operates via
email. Send mail containing only the word HELP to ftpmail@decwrl.dec.com
or bitftp@pucc.princeton.edu, and the servers will send you instructions
on how to make requests.
The sources with the broadest selection of material are the NASA Ames
SPACE archive and the National Space Science Data Center.
Don't even ask for images to be posted to the net. The data volume is
huge and nobody wants to spend the time on it.
VIEWING IMAGES
The possible combinations of image formats and machines is forebodingly
large, and I won't attempt to cover common formats (GIF, etc.) here. To
read PDS and VICAR (and many other) formats on Unix systems running X,
use XV 2.11, available by anonymous FTP from export.lcs.mit.edu
(18.24.0.12) in contrib/xv-2.11.tar.Z and the other standard X11 FTP
sites.
The FAQ for the Usenet group alt.binaries.pictures discusses image
formats and how to get image viewing software. A copy of this document
is available by anonymous FTP from the Usenet FAQ archives at
pit-manager.mit.edu (18.72.1.58), in directory
pub/usenet/alt.binaries.pictures.
ONLINE ARCHIVES
NASA AMES
Extensive archives are maintained at NASA Ames and are available via
anonymous FTP or an email server. These archives include many images and
a wide variety of documents including this FAQ list, NASA press
releases, shuttle launch advisories, and mission status reports. Please
note that these are NOT maintained on an official basis.
FTP users should connect to ames.arc.nasa.gov (128.102.18.3) and look in
pub/SPACE. pub/SPACE/Index contains a listing of files available in the
archive (the index is about 200K by itself).
To access the archives by email, send a letter to
archive-server@ames.arc.nasa.gov (or ames!archive-server). In the
subject of your letter (or in the body), use commands like:
send SPACE Index
send SPACE SHUTTLE/ss01.23.91.
The capitalization of the subdirectory names is important. All are in
caps. Only text files are handled by the email server at present; use
one of the FTP email servers described in the introduction to this
section for images or programs.
The Magellan Venus and Voyager Jupiter, Saturn, and Uranus CD-ROM image
disks have been put online in the CDROM and CDROM2 directories. The
disks will be rotated on a weekly basis. Thousands of images are
available in these collections.
The GIF directory contains images in GIF format. The VICAR directory
contains Magellan images in VICAR format (these are also available in
the GIF directory). A PC program capable of displaying these files is
found in the IMDISP directory (see the item "VIEWING IMAGES" below).
The NASA media guide describes the various NASA centers and how to
contact their public affairs officers; this may be useful when pursuing
specific information. It's in MISC/media.guide.
Any problems with the archive server should be reported to Peter Yee
(yee@ames.arc.nasa.gov).
NASA SPACELINK
SpaceLink is an online service located at Marshall Space Flight Center
in Huntsville, Alabama. The system is specifically designed for
teachers. The data base is arranged to provide easy access to current
and historical information on NASA aeronautics, space research, and
technology transfer information. Also included are suggested classroom
activities that incorporate information on NASA projects to teach a
number of scientific principles. Unlike bulletin board systems, NASA
Spacelink does not provide for interaction between callers. However it
does allow teachers and other callers to leave questions and comments
for NASA which may be answered by regular mail. Messages are answered
electronically, even to acknowledge requests which will be fulfilled by
mail. Messages are generally handled the next working day except during
missions when turnaround times increase. The mail system is closed-loop
between the user and NASA.
SpaceLink also offers downloadable shareware and public domain programs
useful for science educators as well as space graphics and GIF images
from NASA's planetary probes and the Hubble Telescope.
You can dial in at (205)-895-0028 (300/1200/2400/9600(V.32) baud, 8
bits, no parity, 1 stop bit), or telnet to spacelink.msfc.nasa.gov
(128.158.13.250, also known as xsl.msfc.nasa.gov) if you're on the
Internet. Anonymous FTP capability (password guest) is now available.
Most of this information is also available from the Ames server in
directory SPACELINK.
NATIONAL SPACE SCIENCE DATA CENTER (NSSDC)
The National Space Science Data Center is the official clearinghouse for
NASA data. The data catalog (*not* the data itself) is available online.
Internet users can telnet to nssdca.gsfc.nasa.gov (128.183.36.23) and
log in as 'NODIS' (no password). You can also get the catalog by sending
email to 'request@nssdc.gsfc.nasa.gov'.
You can also dial in at (301)-286-9000 (300, 1200, or 2400 baud, 8 bits,
no parity, one stop). At the "Enter Number:" prompt, enter MD and
carriage return. When the system responds "Call Complete," enter a few
more carriage returns to get the "Username:" and log in as 'NODIS' (no
password).
The system is menu-driven; topics available as of 4/10/92 are:
1 - Master Directory - NASA & Global Change
2 - Personnel Information Management System
3 - Nimbus-7 GRID TOMS Data
4 - Interplanetary Medium Data (OMNI)
5 - Request data and/or information from NSSDC
6 - Geophysical Models
7 - CANOPUS Newsletter
8 - International Ultraviolet Explorer Data Request
9 - CZCS Browse and Order Utility
10 - Astronomical Data Center (ADC)
11 - STEP Bulletin Board Service
12 - Standards and Technology Information System
Data can be ordered from the NSSDC on CD-ROM and other formats. Among
the many types of data available are Voyager, Magellan, and other
planetary images, Earth observation data, and star catalogs. Viewers for
Macintosh and IBM systems are also available. As an example of the cost,
an 8 CD set of Voyager images is $75. Data may ordered online, by email,
or by physical mail. The postal address is:
National Space Science Data Center
Request Coordination Office
Goddard Space Flight Center
Code 633
Greenbelt, MD 20771
Telephone: (301) 286-6695
Email address: request@nssdca.gsfc.nasa.gov
NSSDCA is also an anonymous FTP site, but no comprehensive list of
what's there is available at present.
SPACE AND PLANETARY IMAGE FACILITY
Available 24 hours a day via anonymous FTP from pioneer.unm.edu. Has
approximately 150 CD-ROM's full of imagery, raw, and tabular data. To
start, get the file:
pioneer.unm.edu:pub/info/beginner-info
This will hopefully give you all of the information you need to get data
from their machine. beginner-info has been translated to other
languages, you should look inside pub/info for the particular language
that meets your needs.
Contact help@pioneer.unm.edu.
SPACE TELESCOPE SCIENCE INSTITUTE ELECTRONIC INFORMATION SERVICE
stsci.edu (130.167.1.2) has a large amount of information about the
Hubble Space Telescope available by anonymous FTP, such as status
reports and newsletters, in addition to material oriented towards HST
observers and proposers. Get the top level README file to begin with.
Contact Pete Reppert (reppert@stsci.edu) or Chris O'Dea
(odea@stsci.edu).
STARCAT
The Space Telescope European Coordination Facility, at ESO/Garching
provides on-line access to a huge astronomical database, featuring
- Observation log files of several satellites/telescopes
(IUE,IRAS,HST,NTT...).
- Spectra and images (IUE, HST).
- Most of the astronomical catalogues (SAO, HR, NGC, PPM, IRAS,
Veron, GSC and many others, more than 50) in a very convenient
way (give center+radius+kind of objects, and you get the
corresponding files!).
Log on as ``starcat'' (no password) on node stesis.hq.eso.org
(134.171.8.100) or on STESIS (DECnet). The files created can be
retreived by FTP. Contact: Benoit Pirenne, bpirenne@eso.org (phone +49
89 320 06 433) at ST-ECF
ASTRONOMICAL DATABASES
The full SAO stellar database is *NOT* available online, probably due to
the 40 MB size. It may be ordered on magnetic tape from the NSSDC. A
subset containing position and magnitude only is available by FTP (see
"Astronomy Programs" below).
nic.funet.fi (128.214.6.100) has a large collection of astronomical
programs for many types of computers, databases of stars and deep sky
objects, and general astronomy information in directory /pub/astro. This
site is mainly for European users, but overseas connections are
possible.
mandarin.mit.edu (18.82.0.21) has the following data available via
anonymous FTP in directory /astro: StarChart v3.2, orbital elements for
bright comets and asteroids, the Yale Bright Star catalog, Saguaro
Astronomy Club Deepsky and Double Star databases, some PC astronomy
programs, and possibly more. Get astro/README. Contact
ccount@athena.mit.edu with questions.
The Ames archives contain a database of 8,436 galaxies including name,
RA, declination, magnitude, and radial velocity in MISC/galaxy.dat.
Supplied by Wayne Hayes (wayne@csri.utoronto.ca).
iris1.ucis.dal.ca (129.173.18.107) has a number of GIFs from Voyager,
Hubble, and other sources available by anonymous FTP in pub/gif (most of
this data is also in SPACE/GIF on the Ames server). Please restrict
access to 5pm - 8am Atlantic time.
pomona.claremont.edu has the Yale Bright Star catalog for anonymous FTP
in directory [.YALE_BSC]. Contact James Dishaw
(jdishaw@hmcvax.claremont.edu).
The Hubble Guide Star catalog is available on CD-ROM for the Mac and PC
for $49.95 US (catalog # ST101).
Astronomical Society of the Pacific
390 Ashton Ave.
San Francisco, CA 94112
Phone: (415) 337-2624 9 AM - 3 PM Pacific Time
FAX: (415) 337-5205
For German (and possibly other European) readers, Jost Jahn has a
service to distribute astronomical data to interested amateurs at cost.
About 30-40 catalogs are available for DM 6..8/disk. Several floppy disk
formats are available. Because of the expense of receiving email on his
system, he asks that you contact him by physical mail:
Jost Jahn
Neustaedter Strasse 11
W-3123 Bodenteich
GERMANY
Phone: FRG-5824-3197
ASTRONOMY PROGRAMS
Various astronomy-related programs and databases posted to the net in
the past are archived for anonymous FTP at multiple sites, including
ftp.uu.net (137.39.1.9). Also see the ASTRO-FTP list posted to sci.astro
monthly, which is more complete than this list.
Astonomical/Space-related sources of interest in comp.sources.unix:
Volume 8: phoon moon phase and date routines
Volume 12,13: starchart starchart program & Yale Star data
Volume 15: moontool shows moon phase picture on Suns
Volume 16: sao reduced SAO catalog
Astonomical/Space-related sources of interest in comp.sources.misc:
Volume 8: moon another moon phase program
Volume 11: starchart starchart program, version 3.2
Volume 11: n3emo-orbit orbit: track earth satellites
Volume 12: starchart2 starchart program, update to version 3.2.1
Volume 13: jupmoons plotter for Jupiter's major moons [in perl]
Volume 13: lunisolar lunisolar (not sure what this does)
Volume 14: ephem-4.21 astronomical ephemeris, v4.21
Volume 14: n3emo-orbit patch to orbit 3.7
Volume 18: planet planet generation simulator
Elwood Downey (e_downey@tasha.cca.cr.rockwell.com), the author of
"ephem", has offered to mail copies to people who can't find it on one
of the archives.
XSAT, an X Window System based satellite tracking program, is
available by anonymous FTP from export.lcs.mit.edu (18.24.0.12) in
contrib/xsat1.0.tar.Z. Contact Dave Curry (davy@ecn.purdue.edu)
for more information.
Xsky, a computerized sky atlas for the X Window System, is available for
anonymous FTP on arizona.edu in the directory [.SOFTWARE.UNIX.XSKY] as
xsky.tarz. Contact Terry R. Friedrichsen (terry@venus.sunquest.com) for
more information.
The "Variable Stars Analysis Software Archive" is available via
anonymous FTP from kauri.vuw.ac.nz (130.195.11.3) in directory
pub/astrophys. This is intended for specialists in this field, and they
would appreciate people from outside New Zealand confining their FTP
access to the astrophys directory, as they pay a significant amount for
Internet access. Contents are relatively sparse at present due to the
youth of the archive - contributions are encouraged. Contact the archive
administrator, Timothy Banks (bankst@kauri.vuw.ac.nz) for more
information.
The "IDL Astronomy Users Library" is available by anonymous FTP from
idlastro.gsfc.nasa.gov (128.183.57.82). This is a central repository for
general purpose astronomy procedures written in IDL, a commercial image
processing, plotting, and programming language. Contact Wayne Landsman
(landsman@stars.gsfc.nasa.gov) for more information.
ORBITAL ELEMENT SETS
The most recent orbital elements from the NASA Prediction Bulletins are
carried on the Celestial BBS, (513)-427-0674. Documentation and tracking
software are also available on this system. The Celestial BBS may be
accessed 24 hours/day at 300, 1200, or 2400 baud using 8 data bits, 1
stop bit, no parity.
Orbital element sets are available via anonymous FTP from the
following sites:
archive.afit.af.mil (129.92.1.66) NASA,TVRO,Shuttle
directory: /pub/space
ftp.funet.fi (128.214.6.100) NASA,TVRO,Molczan,CelBBS,
directory: /pub/astro/pc/satel Shuttle (*)
kilroy.jpl.nasa.gov (128.149.1.165) NASA,Molczan
directory: /pub/space/
SPACE DIGEST ARCHIVES
Copies of back issues of Space Digest are archived on
LISTSERV@UGA.BITNET. Send mail containing the message "INDEX SPACE" to
get an index of files; send it the message "GET filename filetype" to
get a particular file.
LANDSAT AND NASA PHOTOS
You can get black-and-white 1:1M prints, negatives, or positives for
$10, $18, $12 respectively for any Landsat data more than 2 years old
from EDC, (Eros (Earth Resources Orbiting Satellite) Data Center). Call
them at (605)-594-6511. You get 80 meter resolution from the MSS
scanner, 135x180 kilometers on a picture 135x180 mm in size. I think you
have to select one band from (green, red, near IR, second near IR), but
I'm not sure. Digitial data is also available at higher prices.
Transparencies of all NASA photos available to the public can be
borrowed from the NASA photo archive; you can have copies or prints
made.
NASA Audio-Visual Facility
918 North Rengstorff Ave
Mountain View, CA 94043
(415)-604-6270
PLANETARY MAPS
The USGS address for maps of the planets is:
U.S. Geological Survey,
Distribution Branch,
Box 25286, Federal Center, Bldg. 41
Denver, CO 80225
Maps cost $2.40 to $3.10 per sheet (a few come in sets of 2 or 3 sheets).
The best global maps of Mars based on Viking images are 1:15,000,000
scale in 3 sheets. These maps are:
I-1535 (2 sheets only) - relief, albedo, names
I-1535
I-1618 (3 sheets) - relief, names
I-2030 (3 sheets) - relief, topographic contours
I-1802-A,B,C (3 sheets) - geology
There are many other maps as well: 30 sheets at 1:5,000,000 scale in
relief, albedo, geology, photomosaic forms (not all 30 sheets available
in all formats); 140 sheets at 1:2,000,000 scale as photomosaics of the
whole planet, about 100 sheets of interesting sites at 1:500,000 scale
in photomosaic format, and lots of special sheets.
Then there are maps of Mercury, Venus, the Moon, the four Galilean
Satellites, six moons of Saturn and five of Uranus. [Phil Stooke
(stooke@vaxr.sscl.uwo.ca), the author of this item, has offered to
respond to email requests for information on any topic relating to lunar
and planetary maps.]
COMETARY ORBIT DATA
The Central Bureau for Astronomical Telegrams and the Minor Planet
Center announce the sixth edition of the Catalogue of Cometary Orbits in
IAU Circular 4935. The catalogue contains 1292 entries which represent
all known comets through November 1989 and is 96 pages long.
Non-subscribers to the Circulars may purchase the catalogue for $15.00
while the cost to subscribers is $7.50. The basic catalogue in ASCII
along with a program to extract specific orbits and calculate
ephemerides is available on MS-DOS 5.25-inch 2S2D diskette at a cost of
$75.00 (the program requires an 8087 math coprocessor). The catalogue
alone is also available by e-mail for $37.50 or on magnetic tape for
$300.00.
Except for the printed version of the catalogue, the various magnetic
media or e-mail forms of the catalogue do not specifically meantion
non-subscribers. It is possible that these forms of the catalogue may
not be available to non-subscribers or that their prices may be more
expensive than those given. Mail requests for specific information and
orders to:
Central Bureau for Astronomical Telegrams
Smithsonian Astrophysical Observatory
Cambridge, MA 02138, USA
NEXT: FAQ #4/15 - Performing calculations and interpreting data formats
------------------------------
Date: 6 Jan 1993 01:51:45 GMT
From: Jon Leech <leech@mahler.cs.unc.edu>
Subject: Space FAQ 04/15 - Calculations
Newsgroups: sci.astro,sci.space,news.answers
Archive-name: space/math
Last-modified: $Date: 93/01/05 20:24:49 $
PERFORMING CALCULATIONS AND INTERPRETING DATA FORMATS
COMPUTING SPACECRAFT ORBITS AND TRAJECTORIES
References that have been frequently recommended on the net are:
"Fundamentals of Astrodynamics" Roger Bate, Donald Mueller, Jerry White
1971, Dover Press, 455pp $8.95 (US) (paperback). ISBN 0-486-60061-0
NASA Spaceflight handbooks (dating from the 1960s)
SP-33 Orbital Flight Handbook (3 parts)
SP-34 Lunar Flight Handbook (3 parts)
SP-35 Planetary Flight Handbook (9 parts)
These might be found in university aeronautics libraries or ordered
through the US Govt. Printing Office (GPO), although more
information would probably be needed to order them.
M. A. Minovitch, _The Determination and Characteristics of Ballistic
Interplanetary Trajectories Under the Influence of Multiple Planetary
Attractions_, Technical Report 32-464, Jet Propulsion Laboratory,
Pasadena, Calif., Oct, 1963.
The title says all. Starts of with the basics and works its way up.
Very good. It has a companion article:
M. Minovitch, _Utilizing Large Planetary Perubations for the Design of
Deep-Space Solar-Probe and Out of Ecliptic Trajectories_, Technical
Report 32-849, JPL, Pasadena, Calif., 1965.
You need to read the first one first to realy understand this one.
It does include a _short_ summary if you can only find the second.
Contact JPL for availability of these reports.
"Spacecraft Attitude Dynamics", Peter C. Hughes 1986, John Wiley and
Sons.
"Celestial Mechanics: a computational guide for the practitioner",
Lawrence G. Taff, (Wiley-Interscience, New York, 1985).
Starts with the basics (2-body problem, coordinates) and works up to
orbit determinations, perturbations, and differential corrections.
Taff also briefly discusses stellar dynamics including a short
discussion of n-body problems.
COMPUTING PLANETARY POSITIONS
More net references:
Van Flandern & Pullinen, _Low-Precision Formulae for Planetary
Positions_, Astrophysical J. Supp Series, 41:391-411, 1979. Look in an
astronomy or physics library for this; also said to be available from
Willmann-Bell.
Gives series to compute positions accurate to 1 arc minute for a
period + or - 300 years from now. Pluto is included but stated to
have an accuracy of only about 15 arc minutes.
_Interactive Computer Ephemeris_ (from the US Naval Observatory)
distributed on IBM-PC floppy disks, $35 (Willmann-Bell). Covers dates
1800-2049.
"Planetary Programs and Tables from -4000 to +2800", Bretagnon & Simon
1986, Willmann-Bell.
Floppy disks available separately.
"Fundamentals of Celestial Mechanics" (2nd ed), J.M.A. Danby 1988,
Willmann-Bell.
A good fundamental text. Includes BASIC programs; a companion set of
floppy disks is available separately.
"Astronomical Formulae for Calculators" (4th ed.), J. Meeus 1988,
Willmann-Bell.
"Astronomical Algorithms", J. Meeus 1991, Willmann-Bell.
If you actively use one of the editions of "Astronomical Formulae
for Calculators", you will want to replace it with "Astronomical
Algorithms". This new book is more oriented towards computers than
calculators and contains formulae for planetary motion based on
modern work by the Jet Propulsion Laboratory, the U.S. Naval
Observatory, and the Bureau des Longitudes. The previous books were
all based on formulae mostly developed in the last century.
Algorithms available separately on diskette.
"Practical Astronomy with your Calculator" (3rd ed.), P. Duffett-Smith
1988, Cambridge University Press.
"Orbits for Amateurs with a Microcomputer", D. Tattersfield 1984,
Stanley Thornes, Ltd.
Includes example programs in BASIC.
"Orbits for Amateurs II", D. Tattersfield 1987, John Wiley & Sons.
"Astronomy / Scientific Software" - catalog of shareware, public domain,
and commercial software for IBM and other PCs. Astronomy software
includes planetarium simulations, ephemeris generators, astronomical
databases, solar system simulations, satellite tracking programs,
celestial mechanics simulators, and more.
Andromeda Software, Inc.
P.O. Box 605
Amherst, NY 14226-0605
COMPUTING CRATER DIAMETERS FROM EARTH-IMPACTING ASTEROIDS
Astrogeologist Gene Shoemaker proposes the following formula, based on
studies of cratering caused by nuclear tests.
(1/3.4)
D = S S c K W : crater diameter in km
g p f n
(1/6)
S = (g /g ) : gravity correction factor for bodies other than
g e t Earth, where g = 9.8 m/s^2 and g is the surface
e t
gravity of the target body. This scaling is
cited for lunar craters and may hold true for
other bodies.
(1/3.4)
S = (p / p ) : correction factor for target density p ,
p a t t
p = 1.8 g/cm^3 for alluvium at the Jangle U
a
crater site, p = 2.6 g/cm^3 for average
rock on the continental shields.
C : crater collapse factor, 1 for craters <= 3 km
in diameter, 1.3 for larger craters (on Earth).
(1/3.4)
K : .074 km / (kT TNT equivalent)
n empirically determined from the Jangle U
nuclear test crater.
3 2 19
W = pi * d * delta * V / (12 * 4.185 * 10 )
: projectile kinetic energy in kT TNT equivalent
given diameter d, velocity v, and projectile
density delta in CGS units. delta of around 3
g/cm^3 is fairly good for an asteroid.
An RMS velocity of V = 20 km/sec may be used for Earth-crossing
asteroids.
Under these assumptions, the body which created the Barringer Meteor
Crater in Arizona (1.13 km diameter) would have been about 40 meters in
diameter.
More generally, one can use (after Gehrels, 1985):
Asteroid Number of objects Impact probability Impact energy
diameter (km) (impacts/year) (* 5*10^20 ergs)
10 10 10^-8 10^9
1 1 000 10^-6 10^6
0.1 100 000 10^-4 10^3
assuming simple scaling laws. Note that 5*10^20 ergs = 13 000 tons TNT
equivalent, or the energy released by the Hiroshima A-bomb.
References:
Gehrels, T. 1985 Asteroids and comets. _Physics Today_ 38, 32-41. [an
excellent general overview of the subject for the layman]
Shoemaker, E.M. 1983 Asteroid and comet bombardment of the earth. _Ann.
Rev. Earth Planet. Sci._ 11, 461-494. [very long and fairly
technical but a comprehensive examination of the
subject]
Shoemaker, E.M., J.G. Williams, E.F. Helin & R.F. Wolfe 1979
Earth-crossing asteroids: Orbital classes, collision rates with
Earth, and origin. In _Asteroids_, T. Gehrels, ed., pp. 253-282,
University of Arizona Press, Tucson.
Cunningham, C.J. 1988 _Introduction to Asteroids: The Next Frontier_
(Richmond: Willman-Bell, Inc.) [covers all aspects of asteroid
studies and is an excellent introduction to the subject for people
of all experience levels. It also has a very extensive reference
list covering essentially all of the reference material in the
field.]
MAP PROJECTIONS AND SPHERICAL TRIGNOMETRY
Two easy-to-find sources of map projections are the "Encyclopaedia
Brittanica", (particularly the older volumes) and a tutorial appearing
in _Graphics Gems_ (Academic Press, 1990). The latter was written with
simplicity of exposition and suitability of digital computation in mind
(spherical trig formulae also appear, as do digitally-plotted examples).
More than you ever cared to know about map projections is in John
Snyder's USGS publication "Map Projections--A Working Manual", USGS
Professional Paper 1395. This contains detailed descriptions of 32
projections, with history, features, projection formulas (for both
spherical earth and ellipsoidal earth), and numerical test cases. It's a
neat book, all 382 pages worth. This one's $20.
You might also want the companion volume, by Snyder and Philip Voxland,
"An Album of Map Projections", USGS Professional Paper 1453. This
contains less detail on about 130 projections and variants. Formulas are
in the back, example plots in the front. $14, 250 pages.
You can order these 2 ways. The cheap, slow way is direct from USGS:
Earth Science Information Center, US Geological Survey, 507 National
Center, Reston, VA 22092. (800)-USA-MAPS. They can quote you a price and
tell you where to send your money. Expect a 6-8 week turnaround time.
A much faster way (about 1 week) is through Timely Discount Topos,
(303)-469-5022, 9769 W. 119th Drive, Suite 9, Broomfield, CO 80021. Call
them and tell them what you want. They'll quote a price, you send a
check, and then they go to USGS Customer Service Counter and pick it up
for you. Add about a $3-4 service charge, plus shipping.
A (perhaps more accessible) mapping article is:
R. Miller and F. Reddy, "Mapping the World in Pascal",
Byte V12 #14, December 1987
Contains Turbo Pascal procedures for five common map projections. A
demo program, CARTOG.PAS, and a small (6,000 point) coastline data
is available on CompuServe, GEnie, and many BBSs.
Some references for spherical trignometry are:
_Spherical Astronomy_, W.M. Smart, Cambridge U. Press, 1931.
_A Compendium of Spherical Astronomy_, S. Newcomb, Dover, 1960.
_Spherical Astronomy_, R.M. Green, Cambridge U. Press., 1985 (update
of Smart).
_Spherical Astronomy_, E Woolard and G.Clemence, Academic
Press, 1966.
PERFORMING N-BODY SIMULATIONS EFFICIENTLY
"Computer Simulation Using Particles"
R. W. Hockney and J. W. Eastwood
(Adam Hilger; Bristol and Philadelphia; 1988)
"The rapid evaluation of potential fields in particle systems",
L. Greengard
MIT Press, 1988.
A breakthrough O(N) simulation method. Has been parallelized.
L. Greengard and V. Rokhlin, "A fast algorithm for particle
simulations," Journal of Computational Physics, 73:325-348, 1987.
"An O(N) Algorithm for Three-dimensional N-body Simulations", MSEE
thesis, Feng Zhao, MIT AILab Technical Report 995, 1987
"Galactic Dynamics"
J. Binney & S. Tremaine
(Princeton U. Press; Princeton; 1987)
Includes an O(N^2) FORTRAN code written by Aarseth, a pioneer in
the field.
Hierarchical (N log N) tree methods are described in these papers:
A. W. Appel, "An Efficient Program for Many-body Simulation", SIAM
Journal of Scientific and Statistical Computing, Vol. 6, p. 85,
1985.
Barnes & Hut, "A Hierarchical O(N log N) Force-Calculation
Algorithm", Nature, V324 # 6096, 4-10 Dec 1986.
L. Hernquist, "Hierarchical N-body Methods", Computer Physics
Communications, Vol. 48, p. 107, 1988.
INTERPRETING THE FITS IMAGE FORMAT
If you just need to examine FITS images, use the ppm package (see the
comp.graphics FAQ) to convert them to your preferred format. Failing
that, the basic reference for FITS may be found in the following 3
papers:
Wells, D. C., Greisen, E. W., and Harten, R. H., "FITS: a
flexible image transport system," Astronomy and Astrophysics
Supplement Series, 44, 363-370, 1981.
Grosbol, P., Harten, R. H., Greisen, E. W., and Wells, D. C.,
"Generalized extensions and blocking factors for FITS,"
Astronomy and Astrophysics Supplement Series, 73, 359-364, 1988
Harten, R. H., Grosbol. P., Greisen, E. W., and Wells, D. C.,
"The FITS tables extension, Astronomy and Astrophysics
Supplement Series, 73, 365-372, 1988.
A DRAFT document describing FITS and the Floating Point Agreement
defining FP storage formats is available by anonymous FTP from
nssdca.gsfc.nasa.gov (128.183.36.23). Get ANON_DIR:[FITS]README.;1 to
begin with. There are known to be errors and ambiguities in this
document, so it should not be used as a fundamental reference. Questions
should be sent by email to the FITS support office
(bschlesinger@nssdca.gsfc.nasa.gov) or telephone at (301)-513-1634
A FORTRAN library for reading and writing FITS files is available by
anonymous FTP from tetra.gsfc.nasa.gov (128.183.8.77) in directory
pub/fitsio3. Contact the author, William Pence
(pence@tetra.gsfc.nasa.gov) for more details.
SKY (UNIX EPHEMERIS PROGRAM)
The 6th Edition of the Unix operating system came with several software
systems not distributed because of older media capacity limitations.
Included were an ephmeris, a satellite track, and speech synthesis
software. The ephmeris, sky(6), is available within AT&T and to sites
possessing a Unix source code license. The program is regarded as Unix
source code. Sky is <0.5MB. Send proof of source code license to
E. Miya
MS 258-5
NASA Ames Research Center
Moffett Field, CA 94035-1000
eugene@orville.nas.nasa.gov
THREE-DIMENSIONAL STAR/GALAXY COORDINATES
To generate 3D coordinates of astronomical objects, first obtain an
astronomical database which specifies right ascension, declination, and
parallax for the objects. Convert parallax into distance using the
formula in part 6 of the FAQ, convert RA and declination to coordinates
on a unit sphere (see some of the references on planetary positions and
spherical trignometry earlier in this section for details on this), and
scale this by the distance.
Two databases useful for this purpose are the Yale Bright Star catalog
(sources listed in FAQ section 3) or "The Catalogue of Stars within 25
parsecs of the Sun" (in pub/SPACE/FAQ/stars.data and stars.doc on
ames.arc.nasa.gov).
NEXT: FAQ #5/15 - References on specific areas
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End of Space Digest Volume 16 : Issue 006
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