Satellite laser ranging station Simeiz
of the Crimean Astrophysical Observatory

Hardware

The SLR station Simeiz consists of the following basic technical systems:

• laser,
• operation system of the telescope,
• photoreceiver,
• time and frequency service,
• measurement & information system.

The SLR station Simeiz has the following technical characteristics:

	expected overall accuracy of the system	Δ 5 cm
	operating staff	2 persons
	calibration	internal, external
	range of operation	400 - 40000 km
	observed scale	20o - 90o
	maximum angular rate in azimuth and zenith	2 deg/sec
	accuracy of tracking	4 arcmin

The operation system of the telescope consists of three parts:

• telescope,
• step-motor drivers,
• position sensors of the telescope (encoders)

The SLR station Simeiz is equipped by the telescope TPL-1M with the following characteristics:

	optical system	coude focus
	transmitting-receiving system	combined in the same telescope
	primary mirror diameter	1 m
	secondary mirror diameter	0.25 m
	focus distance for 532 nm	11.6 m
	weight	650 kg
	mounting	altazimuth
	field of view	15'* 15'
	stars image diameter	10"
	controlled change of the laser beam divergence on the telescope output	10 - 120"
	magnitude with optical intensifier	up to +15m
	computer for mount tracking	Pentium III, 450 MHz

The peculiarities of the telescope mount are as follows:

	step-motor	ðûä-5
	velocity of tracking possibility	0-2 deg/sec
	encoder resolution	0.4 arcsec
	laser	in coude
	controlled tracking	step by step
	axis oscillation	20"
	accurasy of tracking	20"
	guide	combined in the same telescope

The telescope is equipped with two encoders FerrandControls.

Laser Nd: YAG, Q-swithed have the following characteristics:

	wavelength	532 nm
	pulse energy	30 - 80 mJ
	mode	single PE detection
	pulse width	250-350 ps
	repetition rate	1 Hz
	divergence	5'
	controlled change of the laser beam divergence on the telescope output	10 - 120"

The transmitting-receiving system has start and stop channels.

Start channel consists of

	start detector	self-made (with energy register)
	avalange	FK-19

Stop channel consists of

	PMT	H6533
	pulse amplifier	U3-33
	discriminator	self-made
	time interval counter	SR620 (HP 5370B until 2002)

The SLR station Simeiz is equipped with the photoreceiver with the following characteristics:

	type of photomultiplier	FEU 79
	quantum effectivity at 532 nm	8,00%
	time resolution	100 ps
	optical filter	reflectional golographical filter, 4 nm, 60%
	coefficient of reflection at 532 nm	50%
	width	16 nm

Time and frequency service have the following peculiarities:

	type of time and frequency standard	rubidium standard Ch-74
	number of the time and frequency standard	2
	stability	2*10-11
	type of UTC receiver	GPS TurboRoque SNR-8000;
	accuracy to the UTC by means of GPS system	1 mks;

Measurement and information system consists of

	computer type	Pentium III, 450 MHz
	time interval counters	SR620
	resolution	25 ps
	measuring time with programming time-gates	1 ms
	time-gates width	1 mks
	interval calibration error	120 - 300 ps
	accuracy of detection of events
	discriminator
	discriminator accuracy