INNAME Input UV file name (name) INCLASS Input UV file name (class) INSEQ 0.0 9999.0 Input UV file name (seq. #) INDISK Input UV file disk unit # SNVER Input SN table version 0 => last GAINVER Input CL table to copy to CL#=high+1 and then correct 0=>high APARM control parameters: 1: what data to plot 0=>zenith atmos. delay 1=>clock error 2=>Reference antenna 3=>dispersion 2: Number of terms in time polynomial for zen. atm. delay or dispersion 0 => no atm fitting 3: Number of terms in time polynomial for clock 0 => no clock fitting 4: Create CL table? 0 => not create 1 => create 5: What correction to make in CL table? 0 => only atmosphere 1 => atmosphere + clocks 6: Number of iterations in robust fit to data 0 => none. 7: > 0 -> plot points omitted from fit 8: 0 => output file at evenly distributed times 1 => output file at the CL table times. 9: 0 => no plotting residuals 1 => plot residuals 10: 0 =>plot model vs recalculated data 1 =>plot direct SN table data vs fitted models see help SOURCES Source list ' '=>all. CALSOUR Calibrator list ' ' => all STOKES Stokes type to process SELBAND Bandwidth to select (kHz) SELFREQ Frequency to select (MHz) FREQID Freq. ID to select, 0=>all BIF 0.0 100.0 Lowest IF number 0=>all EIF 0.0 100.0 Highest IF number 0=>all TIMERANG Time range to use. 0=>all ANTENNAS Antennas to select. 0=>all SUBARRAY 0.0 9999.0 Subarray; 0 => 1. NPLOTS Number of plots per page 0=>5, -1=> Don't make plots XINC 0.0 5000.0 Plot every XINC'th point OPTYPE What data to read from the SN table: 'MDEL' => multi band delay 'PHAS' => phase delay 'DISP' => dispersion 'RATE' => fringe rate ' ' => 'MDEL' OUTFILE Table of delays/derivatives for selected set of antennas in format suitable for CLCOR's option 'ATMO'/'ATMD' PRTLEV 0=> no printout. 1 => print coefficients 2 => print coefficients and their errors and rms of residual DOHIST >0 => put coefficients in history file. DOTV -1.0 1.0 > 0 Do plot on the TV, else make a plot file GRCHAN 0.0 8.0 Graphics channel 0 => 1. BADDISK 0.0 9999.0 Disks to avoid for scratch

DELZN Task: This task estimates the zenith atmosphere delay dependence and clock error based on the SN table output for the selected calibrators. For details on how to observe and use DELZN see AIPS Memo 110, "Strategy for Removing Tropospheric and Clock Errors using DELZN". The model that is fit for multi-band delay is MBdel = Clock(t) + Atmo(t) / sin (elevation) where both Clock and Atmo are polynomials in time with the order of the polynomials specified by APARM(3) and APARM(2), resp. Dispersion is fit as Disp(t) / sin (elevation) with the order of the polynomial given by APARM(2). Adverbs: INNAME.....Input UV file name (name). Standard defaults. INCLASS....Input UV file name (class). Standard defaults. INSEQ......Input UV file name (seq. #). 0 => highest. INDISK.....Disk drive # of input UV file. 0 => any. SNVER......Input SN table version. If SNVER is equal zero or greater than the total number of the SN tables then SNVER is equal to the last existing SN table GAINVER....Input CL table version. If GAINVER is equal zero or greater than the total number of the CL tables then GAINVER is equal to the last existing CL table. The input CL table version (GAINVER) is copied to the output CL table version=(the last one+1), and then the output CL table is corrected. APARM......control parameters: 1: what data to plot? 0=> zenith atmosphere delay Actually the following is plotted: VAL(IANT-RANT)-CLOCK(IANT)+ATM(RANT) The relevant polynomial presentation for ATM(IANT) is plotted also 1=> clock error Actually the following is plotted: VAL(IANT-RANT)-ATM(IANT)+ATM(RANT) The relevant polynomial presentation for CLOCK(IANT) is plotted also 2=> reference antenna, if the reference antenna is constant for the whole experiment Actually the following is plotted: -VAL(IANT-RANT)+CLOCK(IANT)+ATM(IANT) The relevant polynomial presentation for ATM(RANT) is plotted also. The polynomial is the same (reference antenna) But data are different as taken with different IANT 3=> dispersion what is plotted is VAL(IANT-RANT)+DISP(RANT) VAL(IANT-RANT) data of SN table; IANT is the antenna number; RANT is the reference antenna number; 2: Number of terms at the polynomial for zenith atmosphere presentation: linear =>2; quadratic => 3 0 => no atmosphere fitting 3: Number of terms at the polynomial for clock presentation: linear =>2; 2 is recommended 0 => no clock fitting 4: Create CL table? 0 => not create 1 => create 5: What correction to make in CL table? 0 => only atmosphere 1 => atmosphere and clocks 6: Number of iteration in robust attempt at a solution 0 => none At each iteration of the input data (SN table), the residual of each data point relative to the solution is found. If the residual exceeds given number of R.M.S, the data are not used in the following solution. 7: > 0 => plot the data samples omitted during the last iteration of the robust solution. 8: What times for the output file to calculate? 0 => output file at the even distributed times at the data time interval. This option is desired when the calibrators and target sources are located at the different UV data. So correction of CL table should be excluded. Put APARM(4) = 0. 1 => output file at the CL table times. 9: 0 => do not plot residuals 1 => plot residuals (in panel separate from values/fit) 10: 0 => plot the requested model (APARM(1)) AND the adjusted data versus time. In the case of OPTYPE='MDEL', the adjusted data are for antenna Ant aparm(1)=0 MBdelays + model(RefAnt) - model(clock) 1 MBdelays + model(RefAnt) - model(Ant) 2 MBDelays - model(Ant) - model(clock) where model(xx) is the fitted polynomila in time for parameter xx. The data samples are drawn as vertical lines and the model of delay, clock, or reference antenna delay is drawn as a connected line, 1 => plot the data directly and the fitted models versus time. The data are vertical lines and the model points are horizontal lines. If the residuals are small, the two then make plus signs. 314 => fource simulated rate for optype='rate' else => use the actual rate from the SN table SOURCES....list of sources to process. ' ' = all; a "-" before any source name means ALL listed sources will be skipped. CALSOUR....list of calibrators to use. ' ' = all; a "-" before any calibrator name means ALL listed calibrators will be skipped. STOKES.....The desired Stokes type of the output data: 'R', 'L', ' '=> all available. SELBAN.....Bandwidth to select (kHz) SELFREQ....Frequency to select (MHz) FREQID.....Frequency ID to select. 0=>all BIF........First IF to process. 0=>all. EIF........Highest IF to process. 0=>all higher than BIF TIMERANG...Time range of the data to be used. In order: Start day, hour, min. sec, end day, hour, min. sec. Days relative to reference date. 0=>all ANTENNAS...A list of the antennas to be calibrated, plotted and corrected. If any number is negative then all antennas listed are ignored. All 0 => use all antennas. SUBARRAY...The subarray to calibrate. Does only one at a time. NPLOTS.....Number of plots per page; 0=>5. If NPLOTS < 0, then no plots are made. XINC.......Plot every XINC'th point OPTYPE.....What data to read from the SN table: 'MDEL' => multi band delay 'DISP' => dispersion 'PHAS' => phase delay Formally OPTYPE = 'PHAS' works, but there is nothing to solve the twopi phase ambiguity 'RATE' => fringe rate The OPTYPE='RATE' is recommended when accuracy using delay is not high (bandwidth is small), but accuracy using fringe rate is better (time averaging is high) ' ' => 'MDEL' OUTFILE....For MDEL: Table of zenith atmosphere delays, clocks shift and their derivatives for selected set of antennas in format suitable for CLCOR's option 'ATMO'. The file format: The first line is number of the data rows. The remaining lines specify the data with one line for each antenna/time as: Column 1: antenna number; Column 2-5: day, hour, min, sec Column 6: zenith atmosphere delay, in cm Column 7: clock delay, in cm Column 8: derivative of the zenith atmosphere delay, in sec/sec*1.0E14 Column 9: derivative of the clock delay (clock drift), in sec/sec*1.0E14 The values given at the atmosphere/clock delay and their derivatives correspond to the desired corrections. CLCOR should add them to the corrected CL table values. For DISP: Table of zenith dispersive delays and their derivatives for selected set of antennas in format suitable for CLCOR's option 'DISP'. The file format: The first line is number of the data rows. The remaining lines specify the data with one line for each antenna/time as: Column 1: antenna number; Column 2-5: day, hour, min, sec Column 6: zenith dispersive delay, in 1/cm Column 7: derivative of the zenith dispersive delay, in sec/m^2/sec*1.0E14 PRTLEV.....0 => Don't print the coefficients. 1 => print the fitted coefficients for each antenna. 2 => print coefficients and their errors and rms of residual for each antenna. DOHIST.....if DOHIST > 0, the gain coefficients are written into the history file. DOTV.......> 0 Do plot on the TV, else make a plot file GRCHAN.....Graphics channel 0 => 1. BADDISK....A list of disks on which scratch files are not to be placed. This will not affect the output file.

DELZN: Task to estimate the zenith delay and clock error dependence on time based on the CALIB output SN table for the selected calibrators. Documenters: L.R. Kogan Related Programs: CLCAL, ELINT PURPOSE Model of the atmosphere delay and the clock error implemented into a correlator never coincides with the actual values. The task restores the residual atmosphere delay at the given elevation observing calibrators at wide range of elevations. The task reads the SN table, taking the information about the delays (rate) at given antenna observing given calibrator. This delay (rate) is contributed by delay at the atmosphere and delay (rate) due to the clock error. The task separates the atmosphere and clock delays using the least square method to fit polynomial of the chosen degree to the clock error and polynomial of the chosen degree for the zenith atmosphere delay. Having known these polynomials the task calculates the zenith atmosphere delay and records it to the output file ready for use as input file for the task CLCOR (option 'atmov'). The fitted zenith atmosphere delay and clock error is used to correct the delay for target sources putting the correction to the output CL table by the same way CLCOR does at option 'atmov'. For details on how to observe and use DELZN (OPTYPE='mdel') see AIPS Memo 110, "Strategy for Removing Tropospheric and Clock Errors using DELZN". Leonia's explanantion of APARM(10) 10: 0 =>plotting model vs recalculated data for example: OPTYPE=MDEL; then the direct SN table data are: VAL(IANT-RANT) = MODEL_ZATM_IANT*MAP_IANT - MODEL_ZATM_RANT*MAP_RANT + MODEL_CLOCK (1) If we want to plot zenith atmosphere at the IANT APARM(1)=0 then the fitted model of zenith atmosphere at the IANT MODEL_ZATM_IANT is derived from the equation(1) and plotted as the function of SN table data VAL(IANT-RANT) and of MODEL_ZATM_RANT and of MODEL_CLOCK. Thus, the following equation is plotted: MODEL_ZATM_IANT = [VAL(IANT-RANT)+ MODEL_ZATM_RANT*MAP_RANT - MODEL_CLOCK] / MAP_IANT (2) The relevant polynomial presentation for the zenith atmosphere at the IANT is plotted also. 1 =>plotting direct data versus fitted models: The direct data from SN table VAL(IANT-RANT) (left side of the equation 1) is plotted versus the right side of the equation 1. The relevant models are the fitting polinomials.