Why are the 'Fixed Stars' so FIXED?

On May 23, 2:30 am, HW@....(Henri Wilson) wrote:
On 22 May 2007 21:47:24 -0700, Jerry wrote:

On May 22, 6:03 pm, HW@....(Henri Wilson) wrote:
On 22 May 2007 04:55:44 -0700, Jerry wrote:

I made a factor of two error, since 43000 km is the round-trip
discrepancy, i.e. the DSN engineers overestimate the distance
by 21500 km.

YOU, however, don't seem to know how radar ranging works.

If radio signals from DSN to Cassini take a total time of
8666.66 seconds (ignoring transponder delay) to travel
from the ground to Cassini and back, then the range to
Cassini is calculated to be
300000*8666.66/2 km = 1299999000 km

If radio signals from DSN to Cassini take a total time of
8666.80 seconds (ignoring transponder delay) to travel
from the ground to Cassini and back, then the range to
Cassini is calculated to be
300000*8666.80/2 km = 1300020000 km

I just love the way you managed to turn five significant
figures into ten.....hohahaha!

A basic engineering rule is that you do not prematurely round
intermediate results. It is only at the end of your calculations,
when you are ready to report your final figures to others, that
you round to an appropriate number of significant digits so as
to properly convey the precision/accuracy of your results.

Premature rounding allows "dirt" to creep into your calculation.

1300020000 - 1299999000 equals 21000 km

The speed of Cassini has nothing to do with this ranging
calculation.

Who needs the holiday, Henri?

You are more stupid than I thought...but then, after all,
you are a relativist....

It is the distance Cassini moves in 0.14 seconds that
matters...ie., 1.4 km.

You seem to think Cassini travels at light speed.

(sigh)

Let us assume that you are a radar operator.

Q: You send a pulse of radio waves at a target, and the echo
returns after 1 second. How far away is the target?
A: 150,000 km. You take the speed of light, multiply by the
round trip travel time, and divide by two.

Q: You send a pulse of radio waves at a target, and the echo
returns after 2 seconds. How far away is the target?
A: 300,000 km. You take the speed of light, multiply by the
round trip travel time, and divide by two.

Q: You send a pulse of radio waves at a target, and the echo
returns after 1.14 seconds. How far away is the target?

This last question is for YOU to fill in the answer.

You must be bloody mad if you think you can bounce radar off
Cassini....

DSN sends radio signals to Cassini, which responds back.

Now, answer the question.

Let us assume that you are a radar operator.

Q: You send a pulse of radio waves at a target, and the echo
returns after 1 second. How far away is the target?
A: 150,000 km. You take the speed of light, multiply by the
round trip travel time, and divide by two.

Q: You send a pulse of radio waves at a target, and the echo
returns after 2 seconds. How far away is the target?
A: 300,000 km. You take the speed of light, multiply by the
round trip travel time, and divide by two.

Q: You send a pulse of radio waves at a target, and the echo
returns after 1.14 seconds. How far away is the target?

This last question is for YOU to fill in the answer.

......I thought you would be too embarrassed to post again....

Who's embarrassed?

Just to make sure you didn't miss anything, let me repeat
the question:

Let us assume that you are a radar operator.

Q: You send a pulse of radio waves at a target, and the echo
returns after 1 second. How far away is the target?
A: 150,000 km. You take the speed of light, multiply by the
round trip travel time, and divide by two.

Q: You send a pulse of radio waves at a target, and the echo
returns after 2 seconds. How far away is the target?
A: 300,000 km. You take the speed of light, multiply by the
round trip travel time, and divide by two.

Q: You send a pulse of radio waves at a target, and the echo
returns after 1.14 seconds. How far away is the target?

This last question is for YOU to fill in the answer.

Jerry