Handbook of RATAN-600 Continuum observer, ver.0.3 (Oct 1998)

1. Antenna RATAN-600 and techniques of observations
2. Ephemerides and time service
3. Problem of "8-points in angle of place"
4. Arrangement of radiometers horns in feed-cabine N1
5. Observations with "South" in lower and upper culminations
6. Calculations of index situation of focus
7. Old variant of the registration program
8. The new registration program
9. Data-reduction of observing F-files
10. Archive of observations of feed-cabine N1
11. Current ajustments and antenna pointing
12. Parameters of radiometers of feed-cabine N1
13. Database CATS supporting system of astrophysical catalogs
14. Flux calibration observations in continuum
15. Spectral points of secondary calibrators
16. Principal formula for data-reducting of calibration sources
17. New parameters of calibtation sources
18. Examples of measurements of calibration sources
19. What and how the observator must do

1. Antenna RATAN-600

Radio Astronomical Telescope Academy Nauk (science) of Russia is one of the two big telescope of Special Astrophysical Observatory. BTA and RATAN-600 are largest optical and radio telescopes in Russia.

RATAN has seen 'first light' from source PKS 0521-36 12 July 1974 . Since more 50000 observations were caried out in continuum. Main advantage of the telescope is multi-frequiency (1 - 31 cm wavelength) and high bright temperature sensitivity.

Proposals for observational time we ask to send to KTBT .

In the end of 1985 a new conical mirror and feed-cabine N6 was firstly used. That feed-cabine aloows to collect radio emission from whole circle, but range of source declinations limited in this regime the zone of zenith distance z=±6^o (or Dec: 38-49^o ).

Common plan of telescope (program ratan). Each element of image has reference of describing text, use click of mouse.

2. Ephemerides and time service

In MS DOS efemerides of sources could be calculate in program EFRAT , created in SpbITA. In database of EFRAT there are two files of parameters from 1976 to 1990 fd7690 and file jd9000 from 1990 to 2000. Two editable files efrat.ini and obser.dat allow to change location of the observatory and time zone. Ephemerides of the Sun, Moon, planets and Galiley satellites of Jupiter also as stars and radio sources could calculate from EFRAT. In Linux the programs of efemerides epoch . or task preparation of observation could be used.

In two figures the correction values UT1-UTC1 are given for period 1979 - 1996.

These corrections are smaller one second. Be careful in two dates: 31.12 - 1.01 and 30.06 - 01.07. Thus for determined azimuth

It should be noted, that in North sector railways have systematic error in limits of 10-15 mm, thus "correct" position of carriage changes likely. But as usualy observer uses the same position of carriage in sets of observations. So some years position of the horn of 7.6 cm radiometer, '1058 mm' was correct for all range of elevations.
In figure plot of changing of moments of source culminations with fixed position of horn, recalculated on value of carriage, in dependence on the focal distance.

At least, for addition of records, received in different epoch, this records could carry to same epoch or to take into account changing of nutationin same period.

Program jdate [dd/mm/yy] or [jd] outputs Julian day or gives current date from Julian day, (plus day of weak and deltaUT1 in 1980-1996 with accuracy of ±0.02s) .

The programs stime (DOS) and stm calculate mean sideral time on any date (usage: stime [hh] [mm] [ss] [dd/mm/yy] ). This program takes into account passage to summer time.

Remember: in summer time correction to Greenwich time is 4 hours, for winter it is 3 hours. From 1996 this transfer became to do in last sunday of October, as in most of European counties.

Here the plot of nutation in Right ascention are shown in 1979-2001. It could be used for estimate of changing of nutation.

Refraction was involved in account of horizon coordinates as in table:

Table radio refraction

This dependence could be roughly fitted by formula

Plot of radio refraction near RATAN-600 and its approximation of by 5-power polynome in refra (DOS).

Number of antenna elements in dependence on elevation of source: Second column gives horizon size of antenna, from formula

Calculated beam of RATAN North sector antenna at 7.6 cm (H=51^o). Horizon HPBW (in Azimuth) is equal 60", and vertical one - 15'. Base is equal 10 % of maximum value.

3. Problem of "8 points in angle of place"

4. Arrangement of horns feed-cabine N1

1976 to 1980 program carra80

1980 to 1992 program carra89

1993 to 15.03 1994 program carra93

1994 to 04.11 1996 program carra94

1996 to now program cavrra96

(by S.Trushkin)
Current and last year carriage of feed-cabine N1

Velosity of moving source image in focal line defined by formula, coincident with direct measurements:

			    21.23*cos(delta)
North                  V  =  ---------------    mm/s
			      1 + cos(H)

South +flat mirror      =  10.537*cos(delta)  mm/s

Geometric optics gives
	V  = 15*cos(delta)*(r0=288470mm)/(1+cos(h))*sin(1")=
	     =20.92*cos(delta)/( 1+cos(h) ) mm/s

5. Observations with "South" in lower and upper culminations

|---------------------------------------------------------------------|
h=90o                                      flat         h=43o50'    h=0
|       h>60o                                |  h<60o     |           |
|                                            |            |           |
|                                            |            |           |
|  Fcalc 20       40       60       80      100      120  |  140 m    |
C--------|--------|--------|--------|--------|--------|---|----|------| S
|                                            |            |           |
|           upper            c u l m i n a t |i o n       | lower cul.|
|                                            |            |           |
43o50' dec:                                  75o         90o         46o
|---------------------------------------------------------------------|

6. Calculations of index situation of focus

Distance between imaginary focus and index of feed-cabine N1 (S. Golosova)

15.09.82 4884 mm

03.11.89 4869 mm

19.01.95 4862 mm

05.03.97 48?? mm

For N2 : 4926 mm

Plot of calculated focus Fcalc via elevation, as output by program focus.
Fcalc = (1-F){R_max - 445.0(1/cos(h/2) -1) }, where

R_max = 288470 mm;

R_min = 287530 mm;

F = (1 - K cosh)/(1 + cosh);

K = sqrt(1 - (R_min/R_max)²).
For elevation 5^o 1 mm of focus is equal 33" in elevation
For elevation 10^o 1 mm of focus is equal 15"
For elevation 20^o 1 mm of focus is equal 7"
For elevation 44^o 1 mm of focus is equal 3"
For elevation 75^o 1 mm of focus is equal 1"
For elevation 95^o 1 mm of focus is equal 0.5"

Plots elevation of source h and hour angle t from current declination for antenna azimuths: 0, 30, 60 and 90^o.

Calculation of beam and transverse aberration using algorithms by A.N. Korzhavin, rewiting in C by O. Verkhodanov and S. Trushkin. Thus any beam for real observations could be calculated.

There are version for LINUX aberr , gs and be.
and for MS DOS aber and gst.

Plot of transverse aberration in dependance from shift distance along the carriage of feed cabine for several North sector elevation.

Plot of longitudinal aberration in dependance from shift distance along the railways of feed cabine for several North sector elevation (red - elevation 17^o, yellow - elevation 77^o, green - elevation 87^o).

7. Old variant of the registration program

8. The new registration program

Example of record of source PKS 1830-21  from a  such file obsbur.p .
-----------------------------------------------------------------------------
 Number		  3(o)
 File		 r6906p1830-21		Feed-cabine		1
 Source		 1830-210  		Observer	Bursov
 Date		 06 09 96		Azimuth		    0d00m0.00s
 Elevation	 25d09m23.639s		Horn_WL in Focus	2.70
 Elevation_ef	 25d09m23.640s		Horn			w
 RA 1950	 18h30m41.010s		Carriage		940.00
 Dec1950	-21d05m32.000s		Variant/Type		a/d
 RA_date	 18h33m29.090s		Discret sec		0.10
 Dec_date	-21d03m11.457s		Focus mm		147985.594
 Nutation in RA	 0.211s			Start location		940.00
 Siderial time	 18h33m28.879s		Velocity mm/sec		0.000
 Local    UTC	 20h42m54.855s		V(car)/V(src)		0.00
 Start    time	 18h30m58.88s		Time before RA m	2.500
 Stop     time	 18h35m28.88s		Time after  RA m	2.000
-----------------------------------------------------------------------------
 Channel Wave_cm Stocks Regime	Clv_K	Gain Tau Compress W_shift E_shift sec
  2	 2.70	   I	BS	1.35	+ 5  0.00    1	  0.00	-9.23
  4	 7.60	   I	SH	0.41	+ 4  0.00    1	  11.35	 13.70
  5	 13.00	   I	SH	2.00	- 4  0.00    1	 -40.39	-40.39
  9	 31.00	   I	SH	1.90	- 5  0.00    1	  66.25	 66.25
  3	 3.90	   I	BS	1.00	+ 3  0.00    1	 -14.62	-29.81
  8	 1.38	   I	BS	1.70	+ 5  0.00    1	 -4.71	-80.96
-----------------------------------------------------------------------------