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Messages - ZhipengLiang

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Ideas / Re: Making satellites visible during daylight ranging
« on: October 13, 2017, 12:53:55 PM »
We in Changchun also saw Envisat in daylight. Attached is the screenshot when that happened. It was morning. Ignore that system time, it was wrong. The satellite and the beam can both be seen. We used 532nm band pass filter to let in the laser back-scatter, but Envisat was so bright that it is also visible.

Attached are two presentation slides converted to zipped image folders.  I put them in automation session, but it turned out that mine was actually semi-automation  :o  . Whatever they are here now. Please reply to tell me your thoughts about my work.

Dr. Kucharsky gave a brilliant presentation about Ajisai optical measurement. It's possible to recover the state of every single mirror on it. Even found a crack on one of the mirrors.
It's awesome! Hope you could see it. :D

Open a Discussion / Re: Tracking CZ-2C rocket bodies with NORMAL laser
« on: October 12, 2017, 03:09:59 AM »
Dear Zhipeng,

what is the per pulse energy of the laser you used for the tracking of the rocket bodies?

Thanks and best


Hi Sven,

It's our normal SLR laser, with 1mJ pulse energy and 1kHz repetition rate, making 1W laser power. I think other high rate station could do it as well or better.


Open a Discussion / Re: Tracking CZ-2C rocket bodies with NORMAL laser
« on: September 04, 2017, 08:34:09 AM »
Dear Zhipeng,

Borowiec tracks regulary (since January 1, 2017) two CZ2C targets, 28480 and 31114. They give us very interesting results.

Kind regards,

I am very happy to hear that. And I have good news that Changchun's historical data about these two targets are now disclosed. You can access them with the following FTP server:

IP address: []
user: laserspinrb              password: Pa55w0rd_2017                     access: read only

For now both targets' normal point data till April 2017 are online. For fullrate data, I still have problem in preserving multiple reflection patterns. Any help is welcome.

The access is now read-only. May make it read-write access or even move to sddis, if people are interested.

Station Operational Questions / Re: Normal Points software
« on: November 15, 2016, 04:04:57 AM »
Hi Matt

May I also have a piece of this code? Thanks in advance.
Changchun normally uses polynomial fitting to flat the residual, and cubic spline for special targets like defunct Topex. But we also worry about deviating from the 'mainstream' data processing. If there would be some standard subroutines to call, it will be much better, as like the SOFA case.  :)

Hi Manuel

We're going to send you some of our FORTRAN (not C) that will enable you to adjust the orbit to get flat residuals from which you can generate NPs using the link Evan sent.

Hopefully you can use this to develop what you need


Open a Discussion / Tracking CZ-2C rocket bodies with NORMAL laser
« on: October 17, 2016, 09:42:09 AM »
The Changchun Observatory has been tracking the CZ-2C rocket bodies for a whole year, using the normal picosecond KHz laser, along with normal ILRS missions, but with TLE prediction. The Graz people also has found reflective CZ R/B(s) earlier this year, but we are not sure how they are progressing.

We are planning to track other R/B's, of which the number is huge. So we need you to join up.

Below is the list of R/B target already tracked by SLR. Newly joining stations shall try with them.
TLE#          First tracked by
 28480         Changchun7237
 31114         Changchun7237
 38253         Graz7839

Based on our space debris tracking campaign in 2014, below is other R/Bs that would hopefully carry reflector(s). But we haven't tried them.

TLE# , Intl.Designater , Object Type
25400  1998-043G   SL-16 R/B
22220  1992-076B   SL-16 R/B
12988  1981-117B   SL-14 R/B
28222  2004-012C   CZ-2C R/B
25723  1999-022C   SL-8 R/B
23343  1994-074B   SL-16 R/B
20671  1990-057B   SL-14 R/B
13771  1983-003B   SL-3 R/B
11327  1979-030B   SL-8 R/B
11267  1979-011B   SL-14 R/B
13121  1982-027B   SL-3 R/B
12904  1981-103B   SL-3 R/B
19275  1988-056B   SL-14 R/B
17912  1987-038B   SL-14 R/B
37932  2011-068C   CZ-2D R/B
22784  1993-055C   SL-14 R/B

If any more you would like to know about this topic, please reply or message me.

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