中国科学院上海天文台天文地球动力学研究中心

Shanghai Astronomical Observatory，CAS

21st International Workshop on Laser Ranging in Canberra, Australia，Nov 5

Fan Shao1,2, Xiaoya Wang1,2

1.Shanghai Astronomical Observatory, Chinese Academy of Sciences, China

2. University of Chinese Academy of Sciences, Beijing 100049, China;

Email: fanshao@shao.ac.cn

Initial combination of our SLR weekly solutions

with other Analysis Centers

Outline

1、 SLR Post Processing

2、precision of our weekly solutions

2

3、Combination Of SINEX

4、 Conclusions and Future plans

3

Measurement modelsTroposphere

Mendes mapping function and Mendes-Pavlis zenith delay

model

Satellite center of massstation dependent in accordance with the official ILRS COM

data

Orbit Models

Geopotential EGM2008，100×100degree

Solid earth tides IERS 2010 Conventions model

Ocean tides FES2004

Ephemeris JPL DE421

Reference Frames

Terrestrial SLRF2014 (a priori station coordinates and station velocities)

Tidal corrections IERS 2010 Conventions

Ocean loading FES2004

Earth Orientation Parameters IERS 14 C04 a priori

Estimated Parameters

Stations

definition: SLR monument (eccentricities subtracted) at mean

epoch of each arc

a priori values: SLRF2014

a priori standard deviation: 1 m

EOP

definition: x-pole, y-pole, UT1-UTC and LOD

epoch: at noon of each day

frequency: daily

a priori values: IERS 14 C04

a priori standard deviation: 20 masec, 2 msec

Range biasesRange biases

for some (non-core) stations

a priori value: 0 m

a priori standard deviation: 1m

1、SLR Post Processing

Tab1 SLR Post Processing strategy

Introducing a modified Fuzzy C-Means

(FCM) clustering algorithm into the

determination of the weights of SLR

station observations.

4

Fig1 Lageos1 Post processing RMS Fig2 Lageos2 Post processing RMS

1、SLR Post Processing

2009 2010 2011 2012 2013 2014 2015 2016 2017 20180.005

0.01

0.015

0.02

0.025

0.03

Time

lageos1 p

ost

pro

cessin

g w

rms/m

m

MEAN=0.0116m

STD=0.0024m

m

2010 2011 2012 2013 2014 2015 2016 2017 20180.005

0.01

0.015

0.02

0.025

0.03

Time

lageos2 p

ost

pro

cessin

g w

rms/m

m

MEAN=0.0100m

STD=0.0031m

m

5Fig3 the precision of some core station

1、SLR Post Processing

2009 2010 2011 2012 2013 2014 2015 2016 2017-0.2

-0.15

-0.1

-0.05

0

0.05

0.1

0.15

0.2

Time

lageos1 p

ost

pro

cessin

g O

-C /

mm

7080

MEAN=0.0069m

STD=0.0107m

m

2009 2010 2011 2012 2013 2014 2015 2016 2017 2018-0.2

-0.15

-0.1

-0.05

0

0.05

0.1

0.15

0.2

Time

lageos1 p

ost

pro

cessin

g O

-C /

mm

7110

MEAN=0.0081

STD=0.0122

m

2009 2010 2011 2012 2013 2014 2015 2016 2017 2018-0.2

-0.15

-0.1

-0.05

0

0.05

0.1

0.15

0.2

Time

lageos1 p

ost

pro

cessin

g O

-C /

mm

7825

MEAN=0.0086m

STD=0.0143m

m

2009 2010 2011 2012 2013 2014 2015 2016 2017 2018-0.2

-0.15

-0.1

-0.05

0

0.05

0.1

0.15

Time

lageos1 p

ost

pro

cessin

g O

-C /

mm

7839

MEAN=0.0064m

STD=0.0087m

m

2009 2010 2011 2012 2013 2014 2015 2016 2017 2018-0.2

-0.15

-0.1

-0.05

0

0.05

0.1

0.15

0.2

Time

lageos1 p

ost

pro

cessin

g O

-C /

mm

7840

MEAN=0.0064m

STD=0.0093m

m

2009 2010 2011 2012 2013 2014 2015 2016 2017 2018-0.2

-0.15

-0.1

-0.05

0

0.05

0.1

0.15

0.2

Time

lageos1 p

ost

pro

cessin

g O

-C /

mm

7941

MEAN=0.0109m

STD=0.0154m

m

6

2、precision of our weekly solutions

2013 2013.5 2014 2014.5 2015 2015.5 2016 2016.5 2017 2017.5 2018-1

0

1

X-p

ole

[m

as]

2013 2013.5 2014 2014.5 2015 2015.5 2016 2016.5 2017 2017.5 2018-1

0

1x 10

-3

Y-p

ole

[m

as]

2013 2013.5 2014 2014.5 2015 2015.5 2016 2016.5 2017 2017.5 2018-0.5

0

0.5

LO

D [m

s]

time/year

SHAO EOP residuals w.r.t EOP C04

mean=0.01,std=0.06

mean=0.08,std=0.17

mean=0.11,std=0.21

2013 2013.5 2014 2014.5 2015 2015.5 2016 2016.5 2017 2017.5 20180

10

20

30

40

50

60

70

80

90

100

time/year

mm

3-D coordinate residuals w.r.t. SLRF2014

SHAO all sites

SHAO core sites

All sites : MEAN=14.66mm STD=3.52mmCore sites: MEAN=9.86mm STD=2.88mm

Fig4 Time series of SHAO 3-D coordinate residuals w.r.t.SLRF2014

Fig5 Time series of EOP residuals w.r.t.C04

X-pole: MEAN=0.11mas STD=0.21mas

Y-pole: MEAN=0.08mas STD=0.17mas

LOD: MEAN=0.01mas STD=0.06ms

7

3、Combination of SINEX

2013 2013.5 2014 2014.5 2015 2015.5 2016 2016.5 2017 2017.5 20180

10

20

30

40

50

time/year

Th

e v

aria

nce

fa

cto

rs o

f e

ach

AC

asi

bkg

dgfi

esa

gfz

grgs

jcet

nsgf

shao

ILRSC ASI BKG DGFI ESA GFZ GRGS JCET NSGF SHAO

Mean 8.85 11.43 20.21 11.67 14.97 10.5 11.75 10.45 11.19

Std deviation 15.37 22.15 23.04 15.66 17.78 15.57 21.77 18.86 18.66

ILRSB ASI BKG DGFI ESA GFZ GRGS JCET NSGF SHAO

Mean 2.87 3.2 17.5 4.16 7.04 4.92 10.87 7.93 *

Std deviation 15.9 4.2 75.74 2.3 4.21 4.46 21.45 10.05 *

Tab2 Mean variance factors of each ac(ILRSC here represents our combined solutions)

Variance factors of each AC

ILRSA ASI BKG DGFI ESA GFZ GRGS JCET NSGF

Mean 7.59 8.03 19.68 8.48 8.75 14.61 8.83 10.53

Std deviation 49.5 18.0 62.31 19.43 15.44 40.51 30.88 17.00

Tab3 Mean scaling factors of each ac

Fig7 The variance factors of each ac in our combined solutions

8

2013 2013.5 2014 2014.5 2015 2015.5 2016 2016.5 2017 2017.5 20180

5

10

15

203-D coordinate residuals w.r.t. SLRF2014 - core sites

mm

time/year

shao

ilrsa

ilrsb

ilrsc

2013 2013.5 2014 2014.5 2015 2015.5 2016 2016.5 2017 2017.5 2018-1

0

1EOP residuals w.r.t. C04

X-p

ole

[m

as]

2013 2013.5 2014 2014.5 2015 2015.5 2016 2016.5 2017 2017.5 2018-1

0

1

Y-p

ole

[m

as]

2013 2013.5 2014 2014.5 2015 2015.5 2016 2016.5 2017 2017.5 2018-0.5

0

0.5

LO

D [m

s]

time/year

shao

ilrsa

ilrsc

shao

ilrsa

ilrsc

shao

ilrsa

ilrsc

SHAO ILRSA ILRSB ILRSC

Mean 10.86 7.73 10.71 8.63

Std 3.88 2.30 2.56 3.05

SHAO ILRSA

XP YP LOD XP YP LOD

Mean 0.11 0.08 0.01 0.09 0.04 0.005

Std 0.21 0.17 0.06 0.14 0.11 0/02

ILRSB ILRSC

XP YP LOD XP YP LOD

Mean* * *

0.09 0.05 0.008

* * *0.14 0.12 0.03

Fig8 3-D WRMS of the core site coordinates residuals with respect to SLRF2014

Fig9 EOP residuals with respect to C04

Tab4 3-D WRMS of the core site coordinates residuals with respect to SLRF2014 (mm)

Tab5 EOP residuals with respect to C04 (mas, ms)

3、Combination of SINEX

9

2013 2013.5 2014 2014.5 2015 2015.5 2016 2016.5 2017 2017.5 2018-20

-10

0

10

20TX w.r.t. SLRF2014

mm

2013 2013.5 2014 2014.5 2015 2015.5 2016 2016.5 2017 2017.5 2018-20

-10

0

10

20TY w.r.t. SLRF2014

mm

2013 2013.5 2014 2014.5 2015 2015.5 2016 2016.5 2017 2017.5 2018-20

-10

0

10

20TZ w.r.t. SLRF2014

mm

time/year

ILRSC

ILRSA

ILRSB

2013 2013.5 2014 2014.5 2015 2015.5 2016 2016.5 2017 2017.5 2018-1

0

1

2

3

time/year

ppb

ILRSC

ILRSA

ILRSB

ILRSA ILRSB

TX TY TZ scale TX TY TZ scale

Mean 0.01 1.89 -6.12 1.36 0.82 1.79 -8.46 1.30

Std 3.72 3.15 5.56 0.46 4.43 3.84 8.25 0.47

SHAO ILRSC

TX TY TZ scale TX TY TZ scale

Mean -1.90 1.65 -0.03 1.13 -0.84 1.25 -0.83 0.86

Std 3.40 3.76 6.66 0.51 3.49 3.36 5.44 0.44

Fig10 The translation parameter with respect to SLRF2014

Fig11 The scale parameter with respect to SLRF2014

Tab6 The translation and scale parameter with respect to SLRF2014 (mm, ppb)

3、Combination of SINEX

Why?

Is it normal？Why?

10

4.Conclusions and Future plans

The precision of our SHAO weekly solutions can meet the needs of ILRS, the mean value of 3-D coordinate residuals w.r.t. SLRF2014 for all sites is 14.66mm,for core sites is 9.86mm, and the mean value of EOP residuals w.r.t. CO4 for XP is 0.11mas, for YP is 0.08mas and for LOD is 0.01ms.

The calculated variance factors show that our SHAO weekly solutions have a same precision with other ACs.

3-D coordinate residuals w.r.t. SLRF2014 and EOP residuals w.r.t. CO4 of our combined product show a good consistency with ILRSA and ILRSB

The trend of our translation parameter TZ and scale Parameter w.r.t. SLRF2014 are different from ILRSA and ILRSB. Why?

11

4.Conclusions and Future plans

Add satellite ETALON1 and ETALON2 to regenerate our SHAO weekly SINEX files and combined products.

Comparing our translation parameters with dynamic geocenter motion.

Comparing our scale parameters with the scale derived from VLBI.

中国科学院上海天文台天文地球动力学研究中心

Shanghai Astronomical Observatory，CAS

21st International Workshop on Laser Ranging in Canberra, Australia，Nov 5

Thank you for your attention！

Email: fanshao@shao.ac.cn