1 BAD_CHANNEL BAD_CHANNEL [List] Update the Bad Channel List for the current backend number (command BACKEND_NUM). The arguments may be : 1. NONE to empty the list 2. n1 n2 ... to insert channels n1, n2, ... in the list 3. -n1 -n2 ... to remove channels n1, n2, ... from the list Without arguments, BAD displays the current list 1 CALIBRATE CALIBRATE CALIBRATE zeroes the current gain array. A new gain array will be computed from the data read by one or several SUBSCAN /CALIBRATE commands ; this gain array will be locked by the next COMPUTE command (see these commands). 1 COMPUTE COMPUTE [N] COMPUTE divides the current signal array by the current gain array and multiply by the correct calibration factor TCAL to obtain a spectrum. This TCAL is computed using the standard choper-wheel formula depending on the temperatures of CHOPPER and ATMOSPHERE, as well as the current optical depths TAU_SIGNAL and TAU_IMAGE, and the efficiencies BEAM_EFF and FORWARD_EFF. See the SUPPLY command to enter values for these, and note that BEAM_EFF should not be higher than FORWARD_EFF. N is the backend number; its default is the value specified in the BACKEND_NUM command. The number of channels will depend on the backend configuration ; two spectra may be obtained if the backend was split (see the BACKEND_NUM command). The computed spectrum may be further be analysed by standard LAS commands 1 DIRECTORY DIRECTORY name Define the directory where the raw data are. Default is your current working directory. Use "*" as argument to process files at Pico-Veleta. This will take into account the specific organisation of the tree directories. 1 GAINS GAINS [N] Plot the current gain values. The gains will be those of Backend number N or by default the backend specified by the BACKENDNUM command. 1 Language CAL\ Language Summary BACKEND_NUM : Choose a backend. BAD_CHANNEL : Update the Bad Channel List. CALIBRATE : Start a new calibration. COMPUTE [N] : Compute a spectrum from the current signal and gains. DIRECTORY [name]: Define the directory where the raw data are. GAINS [N] : Plot the current gain values. SAVE [name] : Saves the current parameters. SUPPLY : Define a calibration parameter. SHOW : Displays the current parameters. SIGNAL : prints out the current signal array. SCAN_NUM N : Process a new scan. SUBSCAN : Read a subscan. 1 SAVE SAVE name SAVE creates a procedure file of name "name.pro", containing all the current parameters of the program. This file may be executed at any time using the @ command : just type "@ name" after the LAS> prompt, pass "@ name" as a parameter when calling LAS. This file is composed of standard LAS, ANALYSE and CAL commands, and may be edited with the EDT editor of DCL. 1 SCAN_NUM SCAN_NUM [n] Reset the scan number to n AND initialise the signal array. Subscans may then be read in by the SUBSCAN /SIGNAL command. 1 SHOW CAL\SHOW [Arg] Displays the specified CAL parameter. If Arg is ALL, all CAL parameters will be listed. Note that you should specify the language because this command is ambiguous with the LAS\SHOW command. 1 SIGNAL SIGNAL Type the current signal array (for debugging only). 1 SUBSCAN SUBSCAN [n] [/SIGNAL w1 w2 [..]] [/CALIBRATE c1 c2 [...]] [/COLD f1 f2 [...]] Read the subscan number N of the current scan. By default, n is the current subscan number incremented by one. The options control which array (ATMOSPHERE, CHOPPER and COLD) is to be increment, and with which gains. These arrays are used in COMPUTE to determine the receiver and system temperatures, and the atmospheric parameters if SUPPLY CAL AUTO has been previously entered (effective only between a CALIBRATE and a COMPUTE command). The program will automatically process all line backends connected at the time of observations. 2 /SIGNAL SUBSCAN/SIGNAL w1 w2 ... Increment the signal array by the weighted sum of the available phases in this subscan, with weights w1, w2, ... 2 /CALIBRATE SUBSCAN/CALIBRATE c1 c2 ... Increment the current gain array by the weighted sum of the available phases in this subscan, with weights c1, c2, ... Also increment the ATMOSPHERE mean value by the average of phases with negative weights, and the CHOPPER mean value by the average of phases wit negative weights. 2 /COLD SUBSCAN/COLD f1 f2 ... Increment the COLD load mean value by the weighted sum of the available phases in this subscan, with weights f1, f2, ... 1 SUPPLY SUPPLY something [value1 [value2 [...]]] [/RECEIVER i] This is a command to introduce calibration parameters as well as observation parameters that were not included in the header (if any). The /RECEIVER option specifies the receiver for which the parameter is valid. AMBIENT temp pressure : ambient temp.(K) and pressure (mbar) ATMOSPHERE sig img : atmospheric temperature (absorbing layers), in both sidebands EFFICIENCY beam forward : antenna beam efficiency, and forward (sky) efficiency CAL AUTO : parameters are normally reset automatically, MANUAL or only by SET command CHOPPER hot cold : chopper temperature hot (or ambient) and cold (liquid N2) TAU sig img : opt.depth in Signal and Image Bands LINE name : enters a name for the observed line (useful for bookeeping purposes).