ILRS Technical Workshop 2019

Stuttgart, 21st-25th October, Germany

Lunar Laser Ranging Research and

Experiment at Yunnan Observatories

1 Yunnan Observatories, CAS, Kunming Yunnan, China

2 Key Laboratory of Space Object and Debris Observation, CAS

3 Youth Innovation Promotion Association (YIPA), CAS

Li Yuqiang1,2,3, Li R1,2,3, Li Z1,2, Zhai D1,2, Fu H, Tang R, Pi X , Zhang H

Xiong Y1

Out l ine

1 . I n t r o d u c t i o n

2 . L L R S y s t e m

3 . L L R O b s e r v a t i o n s

4 . S u m m a r y

3

I n t r o d u c t i o n

4

P h o t o e l e c t r o n s

2

2 2

2

1

4pe q T t t r r a en E G A T T

hc R

=

4

1~ T t r t rE G A

R

Degnan, John J, 1993lri..workU....D

reciprocal ratio to the 4-power of range

direct ratio to the energy of laser, wavelength,

area of receiver, optical efficiency of transmitting

and receiving path，transmitter gain

L L R s y s t e m o f Y u n n a n O b s e r v a t o r i e s

① O p t i c a l S y s t e m

② C o n t r o l S y s t e m

6

Te l e s c o p e ( u p g r a d e d )

Parameter name Value Units

Effective aperture 1060 mm

Primary mirror focal length 1800 mm

Secondary mirror focal

length-240 mm

Pointing accuracy ＜1 ″

Accuracy-ensured tracking

speed - Azimuth0.004-3 °/s

Accuracy-ensured tracking

speed - Altitude0.004-1 °/s

Max angular velocity -

Azimuth6 °/s

B e t t e r s e r v oSponsored by Bureau of Facility

Support and Budget CAS

7

L a s e r T r a n s m i t t i n g O p t i c a l P a t h

Laser

Primary

Secondary

Laser

M4

M7

M8

Rotating

Mirror

M5M6

(532nm)

M3

1.2m

Telescope

Replaced new mirrors

except primary mirror

with high reflectivity.

optics efficency

go through

8

Parameter name Value Units

Wavelength 532 nm

Pulse Energy 3.0 J

Repetition Rate 10 Hz

Pulse Width 10 ns

Divergence Angle 0.5 mrad

Beam Diameter 22 mm

T h e L a s e r

optimized: small divergence

9

R e c e i v i n g O p t i c a l P a t h

Variable

Aperture Filter

Laser

Primary

Secondary

M4

M7

M8

Rotating

Mirror

M5M6

(532nm)

M3

1.2m

Telescope

CMOS

Camera

HQE-

SPAD

reflect

10

H Q E - S PA D

Parameter name Value

Photosensitive Area Diameter 500μm

Quantum Efficiency (@532nm) ＞60%

Dark Count (@1kHz) 15

Recovery Time 50ns

Time Jitter 160ps

11

R a n g i n g C o n t r o l S y s t e m

Rotating Mirror

Computer Laser

Event TimerGPS

Clock

PINHQE-SPAD

Discriminator

Range Gate Generator

Syn. Pulse

10MHz

Prediction

1pps

Transmitting Pulse

Receiving Pulse

Receiving Pulse

Transmitting Pulse

1pps

10MHz

Laser

Trig.

Gate.

12

D a t a C o l l e c t i o n

EPP

GPS Clock

1pps 10MHzTransmitting Signal

Received Signal

A033-ET

EvenTech

L L R O b s e r v a t i o n s

① O b s e r v a t i o n s

② S i g n a l R e c o g n i t i o n

14

R e s i d u a l s o f A p o l l o - 1 5

15

D a t a Ve r i f i c a t i o n

⚫ Results of the Normal Points

http://polac.obspm.fr/PaV/

16

S i g n a l R e c o g n i t i o n

17

S i g n a l R e c o g n i t i o n

signal recognition automatically

18

L L R D a t a s t a t i s t i c s

Date A-15 A-11 A-14 Luna17

2018/01 12 3 4 0

2018/02 10 0 0 0

2018/03 3 0 1 0

2019/03 6 0 0 0

2019/04 1 0 0 0

2019/06 14 1 1 2

Total 46 4 6 2

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Key Points

Pointing & tracking Laser energy & quality

Optical systemDetector

S u m m a r y

Next Step: focus on precision

We got 58 NPs of LLR.

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O u t l o o k

Wavelength： 1064nm

Repetition frequency ：100Hz

Pulse energy: 320mJ

Pulse width: 65ps

optical quality: M2 2.4

Made in China

Aerospace Information Research Institute, CAS

The laser is scheduled to be installed at the Yunnan Observatories next year.

21

A c k n o w l e d g m e n t s

We all wish to thanks：

• Paris Observatory Lunar Analysis Center for

providing predications, validations service, and

many helps.

• Matera station and McDonald station for

giving helps.

• SUN YAT-SEN UNIVERSITY for giving supports.

Thanks for your attention

Li Yuqiang

lyq@ynao.ac.cn