marstime
|
Contents: Description, Arguments, Usage, Examples, Images, Sub-Functions, Related Functions, Source Supported Under Version: > 1.13
Description Displays information on Mars time, including solar longitude
Arguments and Return Values Parameters: None input initially; the user is prompted for the parameters, one at a time Return Value: Nested structures giving the parameters for global and local Mars time
Usage Syntax: marstime() The user will initially be prompted to enter a date and time (Earth date and time, that is) for which to calculate the time parameters for Mars. If this prompt is left blank (just hit enter), it will take the current system time. The accuracy of the outputs depends on the accuracy of the input time. If you are using the current system time, that means the outputs are only as accurate as your system clock. After requesting the date and time, the function will display, in the following order: basic information on Earth time, approximate 2001 Mars Odyssey orbit number (if applicable), and global Mars time parameters (including solar longitude). It will then prompt the user for a set of planetocentric coordinates for which to calculate the local time. When the function prompts for longitude, you can choose a landing site by entering a case-sensitive abbreviation. Abbreviations recognized by the function are: VIK1 for Viking Lander 1, VIK2 for Viking Lander 2, MPF for Mars Pathfinder, MERA for Mars Exploration Rover A (Spirit), MERB for Mars Exploration Rover B (Opportunity), and PHX for Phoenix. The function will then display the local time parameters for that site, display an approximate Mars sunclock, and return a nested structure with the calculated global and local time parameters. See the function pages for marstimeglobal and marstimelocal for details on the returned structure. Most of the equations used in the Mars time calculations are adapted from NASA GISS Mars24 (available at http://www.giss.nasa.gov/tools/mars24/) and Allison, M., and M. McEwen (2000), A post-Pathfinder evaluation of aerocentric solar coordinates with improved timing recipes for Mars seasonal/diurnal climate studies, Planet. Space Sci., 48, 215-235, doi:10.1016/S0032-0633(99)00092-6 (available at http://pubs.giss.nasa.gov/cgi-bin/abstract.cgi?id=al05000n).
Examples dv> marstime() Time on Mars This function's calculations are accurate for the years 1874-2126. See the invididual functions for details on the levels of accuracy. DO NOT enter mathematical expressions with letters - only numbers! e.g. do not enter "pg2pc(19.4724)" or "x" when asked for latitude See http://www.giss.nasa.gov/tools/mars24/help/algorithm.html (Mars24) and http://pubs.giss.nasa.gov/cgi-bin/abstract.cgi?doi=10.1016/ S0032-0633(99)00092-6 (Allison & McEwen 2000) S.Marshall 11-24-2009 First enter an Earth date and time (or leave blank for system clock) Year: Julian Date (UTC): 2455160.323304 Modified Julian Date (UTC): 55159.823304 TT-UTC offset (Delta-T): 66.184000 seconds Uncertainty in Delta-T: 0.000000 seconds Modified Julian Date (TT): 55159.824070 J2000 (TT) offset: 3615.324070 days Ephemeris Time (ET): 312363999.682 (seconds) Warning! This function may not be accurate to even half an orbit beyond orbit 35100 (ET 311291588). Approximate Odyssey orbit number: 35250 Mean anomaly of Mars: 113.892 degrees Angle of the Fictitious Mean Sun of Mars: 4.955 degrees Angular longitude perturbations of Mars: -0.008 degrees Equation of Center of Mars: 9.30 degrees True anomaly of Mars: 123.19 degrees Areocentric solar longitude: 14.25 degrees Early northern spring Heliocentric distance of Mars: 1.5918 AU Heliocentric longitude of Mars: 99.28 degrees Heliocentric latitude of Mars: 1.350 degrees Planetocentric longitude of the subsolar point: 111.32 E Planetocentric latitude of the subsolar point: 6.01 Mars Sol Date (MSD): 48310.212970 Coordinated Mars Time: 05:06:40.6 MTC Equation of Time of Mars: -7.99 degrees = -00:31:57 Now enter planetocentric coordinates of a location on Mars Or enter "VIK1", "VIK2", "MPF", "MERA", "MERB", or "PHX" (without quotes) to use that lander's site Longitude (east is positive, west is negative): MERA Planetocentric coordinates: 175.478 E, -14.754 Planetographic coordinates: 184.522 W, -14.922 Local Martian time zone offset: +12 Local mean zonal time: 17:06:40.6 MTC+12 Local mean solar time: 16:48:35.4 LMST Local true solar time: 16:16:38 LTST Local solar incidence angle (zenith): 67.0 degrees Local solar azimuth: 283.4 degrees Displaying sunclock... ................................................................................................ ................................................................................................ ................................................................................................ ........................................................................ /themis/lib/dav_lib/library/script_files/time/Mars_Viking.jpg: bip JPEG image: 720x360x3, 8 bits Writing /tmp/dv_9494/4FaSZz: 720x360x3 PNG file. Returning data structures... struct, 2 elements global: struct, 15 elements Dt: 3615.32407041016 M: 113.891830444336 aFMS: 4.95494127273560 PBS: -0.00849286187440157 EoC: 9.29501438140869 nu: 123.186843872070 R: 1.59176397323608 hlon: 99.2762756347656 hlat: 1.35040247440338 LS: 14.2499551773071 EoT: -0.532494544982910 MSD: 48310.2129696872 MTC: 5.11127233505249 ssplon: 111.318328857422 decl: 6.01449251174927 local: struct, 11 elements Dt: 3615.32407041016 lon: 175.478500366211 lat: -14.7541999816895 lonpg: 184.521500000000 latpg: -14.9217443466187 timezone: "+12" LMZT: 17.1112747192383 LMST: 16.8098392486572 LTST: 16.2773456573486 Z: 66.9528808593750 A: 283.380920410156
Images
|
DavinciWiki Mini-Nav Bar Contents
Contact Developers
All other topics
Major Sub-Functions
Related Functions
Recent Library Changes Created On: 11-18-2009 |
