Earth-Titan range at Huygens landing?

Can anybody find the predicted Earth-Titan range
at the moment of the Huygens landing Jan 14?
Equivalent: one-way radio signal propagation time.

Jim Oberg wrote:

Can anybody find the predicted Earth-Titan range
at the moment of the Huygens landing Jan 14?
Equivalent: one-way radio signal propagation time.






Yes.

I'm sure someone can....

"Jim Oberg" wrote in
:

Can anybody find the predicted Earth-Titan range
at the moment of the Huygens landing Jan 14?
Equivalent: one-way radio signal propagation time.






http://www.pparc.ac.uk/Nw/Huygens_timeline.asp suggests approximately 66
mins. (about 736 560 000 miles)

--
Colin J Denman
N 51º 54' 38" W 00º 29' 45" Elev: 125m
email: -- use my first name
home: http://www.cjdenman.freeserve.co.uk

Thanks, sounds about right -- current range is about 1.2 billion km.

"Colin J Denman" wrote in message
. 2.87...
"Jim Oberg" wrote in
:

Can anybody find the predicted Earth-Titan range
at the moment of the Huygens landing Jan 14?
Equivalent: one-way radio signal propagation time.






http://www.pparc.ac.uk/Nw/Huygens_timeline.asp suggests approximately 66
mins. (about 736 560 000 miles)

--
Colin J Denman
N 51º 54' 38" W 00º 29' 45" Elev: 125m
email: -- use my first name
home: http://www.cjdenman.freeserve.co.uk

"Colin J Denman" wrote in message

http://www.pparc.ac.uk/Nw/Huygens_timeline.asp suggests approximately 66
mins. (about 736 560 000 miles)

I thought I had read that at least an attempt would be made to pick up
Huygen's signal on Earth as it encounters Titan. Seems like an impossible
task ...

Jon

"Jon S. Berndt" jsb.at.hal-pc-dot.org wrote in
:

I thought I had read that at least an attempt would be made to pick up
Huygen's signal on Earth as it encounters Titan. Seems like an impossible
task ...


http://www.esa.int/SPECIALS/Cassini-...OSXDE2E_0.html

--
Colin J Denman
N 51º 54' 38" W 00º 29' 45" Elev: 125m
email: -- use my first name
home: http://www.cjdenman.freeserve.co.uk

"Colin J Denman" wrote
http://www.esa.int/SPECIALS/Cassini-...OSXDE2E_0.html

Colin:

This is absolutely news to me -- the reason I value these newsgroups so
highly!

Thank you thank you thank you thank you thank you thank you thank you thank
you thank you thank you thank you thank you thank you thank you thank you
thank you thank you thank you thank you thank you thank you thank you thank
you thank you thank you thank you thank you thank you thank you thank you
thank you thank you thank you thank you thank you thank you thank you thank
you thank you thank you thank you!

JimO
www.jamesoberg.com

In article ,
Jon S. Berndt jsb.at.hal-pc-dot.org wrote:
I thought I had read that at least an attempt would be made to pick up
Huygen's signal on Earth as it encounters Titan. Seems like an impossible
task ...

Note that they can detect the transmitter carrier with a *much* weaker
signal than they need to actually demodulate the data off it. Especially
if they record the raw incoming signal in full detail, and then process
the tapes later, when they know exactly what data the signal was carrying.

And yes, this is a useful thing to do -- by watching the signal's Doppler
shift, you can get some data on descent winds.
--
"Think outside the box -- the box isn't our friend." | Henry Spencer
-- George Herbert |

"Jim Oberg" writes:

Can anybody find the predicted Earth-Titan range
at the moment of the Huygens landing Jan 14?
Equivalent: one-way radio signal propagation time.

The JPL Horizons web site (http://ssd.jpl.nasa.gov/horizons.html) lets you
do this with the full accuracy of the JPL code. Asking for Los Angeles
to Titan on 14 Jan 2005, 10-13:00 GMT, we get at 11:30 GMT (predicted
landing time)

67.1063 minutes, or 67 minutes, 6.38 seconds.

Lou Scheffer

----- Text output from the JPL site -------------------------

HORIZONS Generated Ephemeris
************************************************** *****************************
Ephemeris / WWW_USER Sun Dec 19 21:40:10 2004 Pasadena, USA / Horizons
************************************************** *****************************
Target body name: Titan (606) {source: SAT185}
Center body name: Earth (399) {source: DE-0406LE-0406}
Center-site name: (User Defined Site)
************************************************** *****************************
Start time : A.D. 2005-Jan-14 10:00:00.0000 UT
Stop time : A.D. 2005-Jan-14 14:00:00.0000 UT
Step-size : 30 minutes
************************************************** *****************************
Center geodetic : 241.759000, 34.0542, -0.00{E-lon(deg),Lat(deg),Alt(km)}
Center cylindric: 241.759000, 5289.8941, 3551.42{E-lon(deg),Dxy(km),Dz(km)}
Center pole/equ : High-precision EOP model {East-longitude +}
Center radii : 6378.1 x 6378.1 x 6356.8 km {Equator, meridian, pole}
Target pole/equ : IAU_TITAN {East-longitude -}
Target radii : 2575.0 x 2575.0 x 2575.0 km {Equator, meridian, pole}
Target primary : Saturn {source: DE-0406LE-0406}
Interfering body: MOON (Req= 1737.400) km {source: DE-0406LE-0406}
Deflecting body : Sun, EARTH {source: DE-0406LE-0406}
Deflecting GMs : 1.3271E+11, 3.9860E+05 km^3/s^2
Atmos refraction: NO (AIRLESS)
RA format : HMS
Time format : CAL
RTS-only print : NO
EOP file : eop.041217.p050310
EOP coverage : DATA-BASED 1962-JAN-20 TO 2004-DEC-17. PREDICTS- 2005-MAR-09
Units conversion: 1 AU= 149597870.691 km, c= 299792.458 km/s, 1 day= 86400.0 s
Table cut-offs 1: Elevation (-90.0deg=NO ),Airmass (38.000=NO), Daylight (NO )
Table cut-offs 2: Solar Elongation ( 0.0,180.0=NO )
************************************************** *****************************
Date__(UT)__HR:MN delta deldot 1-way_LT
************************************************** *******
2005-Jan-14 10:00 8.0688643220 -1.49705 67.106698
2005-Jan-14 10:30 8.0688469055 -1.40650 67.106553
2005-Jan-14 11:00 8.0688305602 -1.31953 67.106417
2005-Jan-14 11:30 8.0688152392 -1.23674 67.106290
2005-Jan-14 12:00 8.0688008883 -1.15868 67.106171
2005-Jan-14 12:30 8.0687874477 -1.08579 67.106059
2005-Jan-14 13:00 8.0687748523 -1.01843 67.105954
2005-Jan-14 13:30 8.0687630337 -0.95687 67.105856
2005-Jan-14 14:00 A 8.0687519206 -0.90125 67.105763
************************************************** *****************************
[...]
delta deldot =
Target apparent range ("delta") and range-rate ("delta-dot") relative to
observer. Units: AU and KM/S

1-way_LT =
Target 1-way light-time, as seen by observer. The elapsed time since light
(observed at print-time) left or reflected off the target. Units: MINUTES

"Jim Oberg" wrote in message
...
Can anybody find the predicted Earth-Titan range
at the moment of the Huygens landing Jan 14?
Equivalent: one-way radio signal propagation time.




8.17au?

BV.