;+ ; NAME: ; LOFAR_CORE_UV ; PURPOSE: ; Returns OVSA UV coverage for given HA range, Dec, and antennas ; CATEGORY: ; OVSA MISC ; CALLING SEQUENCE: ; uvt = ovsa_uv(harange,hstep,dec,antlist[,halist]) ; INPUTS: ; harange a 2-element array giving the start and end hour-angle, [h]. ; Valid OVSA coverage is limited to the range [-4.0,4.0] ; hstep a float giving the step size in hour angle [h] ; dec the source declination (assumed constant) [deg] ; antlist an integer array specifying the OVSA antennas for which to ; return coverage, e.g. [1,2,4,5,6,7] for all antennas of ; current array. The 7th antenna's approximate location ; can be specified by antenna number 3. ; OPTIONAL (KEYWORD) INPUT PARAMETERS: ; ROUTINES CALLED: ; uvt a float array of size [NANT,NANT,NSTEPS], where NANT is ; n_elements(antlist), and NSTEPS is derived from the HA ; range and step size. The upper non-diagonal elements ; for each step contain the U values, while the lower ; non-diagonal elements contain the V values. The units ; can be thought of as nsec, or wavelengths at 1 GHz. ; A convenient method for plotting the values for all ; returned antennas is: ; plot,[-2000,2000]*2,[-2000,2000]*2,/nodata ; for i = 0, nant-1 do for j = i+1,nant-1 do $ ; oplot, uvt[j,i,*], uvt[i,j,*],psym=3 ; for i = 0, nant-1 do for j = i+1,nant-1 do $ ; oplot,-uvt[j,i,*],-uvt[i,j,*],psym=3 ; halist a float array giving the list of hour angles at which the ; UV points are determined. Optional. ; OUTPUTS: ; COMMENTS: ; SIDE EFFECTS: ; RESTRICTIONS: ; MODIFICATION HISTORY: ; using ovsa_uv by Dale Gary ; changed 7-Oct-20 by eduard.kontar@glasgow ; ;- function lofar_core_uv,harange,hstep,dec,lon,lat ;dec=lat ;conversion to radians lat=lat*!pi/180 lon=lon*!pi/180 ; Constant parameters CMM = 2.997925D2 ; Speed of light [mm/nsec] ;CSLAT = 0.79619623D ; Cosine of OVRO latitude (37d13'53.8") ;SNLAT = 0.60503848D ; Sine of OVRO latitude (37d13'53.8") ;coordinates of Amsterdam ;52.3667° N, 4.9000° E ;lat=!pi* 52.3667/180 ;latitude relative to the equator, positive to north, negative to south ;lon=!pi*(+4.900)/180 ;longitude relative to the zero meridian, positive to east, negative to west ;coordinates of LOFAR core ;52.914610, 6.871362 ;lat=!pi*52.914610/180.0D ;lon=!pi*6.871362/180.0D COSLAT=COS(LAT) SINLAT=SIN(LAT) COSLON=COS(LON) SINLON=SIN(LON) ;stop ;Nominal XYZ coordinates of LBA stations CS001= [3826923.546,460915.441,5064643.489]*1d CS002= [3826577.066,461022.948,5064892.786]*1d CS003= [3826516.748,460930.066,5064946.457]*1d CS004= [3826654.197,460939.576,5064842.426]*1d CS005= [3826668.750,461069.550,5064819.754]*1d CS006= [3826596.730,461145.178,5064866.978]*1d CS007= [3826533.361,461098.966,5064918.721]*1d CS011= [3826667.069,461285.849,5064801.592]*1d CS013= [3826346.265,460792.111,5065087.136]*1d CS017= [3826462.054,461501.950,5064935.827]*1d CS021= [3826406.543,460538.604,5065064.870]*1d CS024= [3827161.234,461409.408,5064421.046]*1d CS026= [3826390.916,461869.852,5064955.913]*1d CS028= [3825600.445,461260.593,5065604.325]*1d CS030= [3826014.266,460387.389,5065372.328]*1d CS031= [3826439.996,460273.833,5065063.594]*1d CS032= [3826891.573,460387.910,5064715.292]*1d CS101= [3825848.343,461689.538,5065378.785]*1d CS103= [3826304.279,462823.089,5064934.334]*1d CS201= [3826708.929,461913.747,5064713.838]*1d CS301= [3827429.462,460990.224,5064257.677]*1d CS302= [3827945.916,459792.639,5063990.016]*1d CS401= [3826766.106,460100.388,5064836.470]*1d CS501= [3825625.779,460642.110,5065640.772]*1d ; RPC = [3826577.110,461022.900,5064892.758]*1d ; reference phase center CS=[[CS001],[CS002],[CS003],[CS004],[CS005],[CS006],[CS007],[CS011],[CS013],[CS017],$ [CS021],[CS024],[CS026],[CS028],[CS030],[CS031],[CS032],[CS101],[CS103],[CS201],$ [CS301],[CS302],[CS401],[CS501]] ; 6-superterp stations ; CS=[[CS001],[CS002],[CS003],[CS004],[CS005],[CS006],[CS007],[CS011],[CS013],[CS017],$ ; [CS021],[CS024],[CS026],[CS028],[CS030],[CS031],[CS032],[CS101],[CS103],[CS201],$ ; [CS301],[CS302],[CS401],[CS501]] CSNAME=['CS001','CS002','CS003','CS004','CS005','CS006','CS007','CS011','CS013','CS017',$ 'CS021','CS024','CS026','CS028','CS030','CS031','CS032','CS101','CS103','CS201',$ 'CS301','CS302','CS401','CS501'] ;CSNAME=INTARR(24) E=dblarr(N_elements(CS(0,*))) N=dblarr(N_elements(CS(0,*))) U=dblarr(N_elements(CS(0,*))) ii=[ -sin(lon), cos(lon), 0.0] jj=[-sin(lat)*cos(lon), -sin(lat)*sin(lon), cos(lat)] kk=[ cos(lat)*cos(lon), cos(lat)*sin(lon), sin(lat)] POSITION=CS-REBIN(RPC,3,N_elements(CS[0,*])) ; in mm E=position[0,*]*ii[0]+position[1,*]*ii[1]+position[2,*]*ii[2] N=position[0,*]*jj[0]+position[1,*]*jj[1]+position[2,*]*jj[2] U=position[0,*]*kk[0]+position[1,*]*kk[1]+position[2,*]*kk[2] ;stop for i=0, n_elements(E)-1 DO BEGIN ENU=XYZ2ENU(CS[*,i],RPC) E[i]=enu[0] N[i]=enu[1] U[i]=enu[2] endfor ; stop Antxyz=[E,N,U]*1000.D0 ; converts to mm ; Antxyz=Position*1000.d0 window,xsize=800,ysize=800 plot,E,N, xrange=[-2000,2000],yrange=[-2000,2000],psym=7, xtitle='W-E, [meters]',ytitle='S-N, [meters]' plots,[0,0],[-2000,2000],line=1 plots,[-2000,2000],[0,0],line=1 x=findgen(2000)-1000+0.5 oplot,x,sqrt(1e3^2-x^2),line=1 oplot,x,-sqrt(1e3^2-x^2),line=1 XYOUTS, E, N,string(CSNAME), CHARSIZE = 1, /data ;XYOUTS,200.,200.,'T',CHARSIZE = 1,/data ; stop ; Nominal Antenna Positions [mm], in E, N, U coordinates ; ; E N U ; -------- -------- -------- ; 60960 0 0 ; 487680 0 0 ; -184090 7320 -12680 ; 13870 128120 -12530 ; 13870 371960 -12340 ; 149962 124920 -12500 ; 1066800 -91440 -12500 ; Approximate location of Ant 3 ; -1 -1 -1 ; antxyz = [[ 60960, 0, 0],$ ; [ 487680, 0, 0],$ ; [-184090, 7320, -12680],$ ; [ 13870, 128120, -12530],$ ; [ 13870, 371960, -12340],$ ; [ 149962, 124920, -12500],$ ; [1066800, -91440, -12500],$ ; Approximate location of Ant 3 ; [ -1, -1, -1]] nant=N_elements(CS[0,*]) ; all antenas are used iant=indgen(N_elements(CS[0,*])) ; antenna numbers ; Create GEOMETRY structure needed for BDOTS argument geometry = {bx:fltarr(nant,nant),by:fltarr(nant,nant),$ bz:fltarr(nant,nant),htdiff:fltarr(nant,nant)} ; Get current baseline corrections, as [X,Y,Z] in nsec for each of eight ; antennas. Unused antennas have zeroes. BLCOR is of size [3,8]. ;blcor = get_blcor() bcor=0.0 ; Create matrix of baselines, with convention that baseline ; Bx = ANTjx - ANTix. i.e. the baseline vector for baseline ij ; goes from ANTi to ANTj. for i = 0, nant-1 do begin for j = i+1, nant-1 do begin ; First get East, North, Up coordinates for baseline ij [nsec] be = (antxyz[0,iant[j]] - antxyz[0,iant[i]])/CMM bn = (antxyz[1,iant[j]] - antxyz[1,iant[i]])/CMM bu = (antxyz[2,iant[j]] - antxyz[2,iant[i]])/CMM ; The height difference for each baseline can be used to ; correct for atmospheric refraction (refractive index n, ; where n - 1 = 0.000285). sgn = 1.0 ;sgn1=0.0 ;removing the correction geometry.htdiff[i,j] = sgn*(bu*0.000285D) geometry.htdiff[j,i] = geometry.htdiff[i,j] ; Convert baseline coordinates from east, north, up to x,y,z ; system of coordinates [nsec] bx = bn*SINLAT - bu*COSLAT by = - be bz = - bn*COSLAT - bu*SINLAT ; Add baseline corrections obtained earlier from BLCIN function. ; geometry.bx[i,j] = sgn*(bx+(blcor[0,iant[i]]-blcor[0,iant[j]])) ; geometry.by[i,j] = sgn*(by+(blcor[1,iant[i]]-blcor[1,iant[j]])) ; geometry.bz[i,j] = sgn*(bz+(blcor[2,iant[i]]-blcor[2,iant[j]])) geometry.bx[i,j] = sgn*bx geometry.by[i,j] = sgn*by geometry.bz[i,j] = sgn*bz geometry.bx[j,i] = geometry.bx[i,j] geometry.by[j,i] = geometry.by[i,j] geometry.bz[j,i] = geometry.bz[i,j] endfor endfor ; Determine the number of HA steps to take nsteps = fix((harange[1] - harange[0])/hstep) if ((harange[0] + nsteps*hstep) le harange[1]) then nsteps = nsteps+1 ;stop ; Declare storage for output uvt = fltarr(nant,nant,nsteps) ; Convert DEC to msec decms = dec*3.6D6 halist = fltarr(nsteps) ; Now loop over HA range, with HASTEP for i = 0, nsteps-1 do begin ; Determine new HA in hours, and save in HALIST ha = float(harange[0]) + i*hstep halist[i] = ha ; Convert HA to msec ha = ha*3.6D6 ; Call BDOTS repeatedly with HA [msec] and DEC [msec] tau = lofar_bdots(ha,decms,geometry,uv) uvt[*,*,i] = uv endfor ;stop return,uvt end