#!/usr/bin/perl
########################################################################
# otfaste.pl -- a perl script to estimate OTF obs parameters for ASTE
#   usage: type "perl otfaste.pl"
#   2006-11-15 for multi-ON/OFF observations
#   2007-10-22 WHSF support
#   2007-10-22 tdump=0.2 for WHSF
#   2014-06-27 WHSF updated
#   2015-02-20 updated for CfP 2015
#   sawada @ NRO
########################################################################

$tapp = 4.;
$ttran = 2.;
$ttranoff = 5.;
$fcal = 16./15.;
$eta  = 4.3;
$etaq = 0.88;
$tdump = 0.1;

printf("### OTF sensitivity estimation for ASTE ###\n");

#	/* BACKEND TYPE */
printf("backend type                            (1:MAC, 2:WHSF): ");
chomp($betype = <STDIN>);

#	/* MAPPING AREA */
printf("length of mapping area (along the scans)    l1 [arcsec]: ");
chomp($len1 = <STDIN>);
printf("length of mapping area (perp. to the scans) l2 [arcsec]: ");
chomp($len2 = <STDIN>);

#	/* TIME FOR SCAN */
printf("time for scan                                 tscan [s]: ");
chomp($tscan = <STDIN>);

#	/* SEQUENCE PATTERN */
printf("number of ONs per OFF                        Nscan(SEQ): ");
chomp($nscanseq = <STDIN>);

#	/* SEPARATION BETWEEN SCANS */
printf("separation between scans              (delta)l [arcsec]: ");
chomp($deltal = <STDIN>);

#	/* MAP GRID */
printf("map grid                                     d [arcsec]: ");
chomp($dgrid = <STDIN>);

#	/* SYSTEM NOISE TEMPERATURE */
printf("system noise temperature                       Tsys [K]: ");
chomp($tsys = <STDIN>);

#	/* RESOLUTION BANDWIDTH */
printf("resolution bandwidth                            B [kHz]: ");
chomp($bandw = <STDIN>);

# printf("----------------------------------------------------------------\n");
#	/* END OF INPUT */

if ($betype == 2) {
	$etaq = 0.60;
	$tdump = 0.2;
}

$vscan = $len1/$tscan;

$nrow = $len2/$deltal + 1;
$tontot = $tscan*$nrow;
$toh = 2.*$ttranoff/$nscanseq + $tapp + ($nscanseq-1)/$nscanseq*$ttran;
$toff = sqrt(($tscan+$toh)*$eta*$nrow*$tscan*$deltal*$dgrid/$len1/$len2 *
	$nscanseq*$nscanseq*$dgrid/(($nscanseq-1)*$deltal+$dgrid));
$toff = int($toff+0.5);

$tobstot = $nrow*($tscan+$toff/$nscanseq+$toh) * $fcal;

$tcellon = $eta*$tontot*$dgrid*$dgrid/$len1/$len2;
$tcelloff = $toff*(($nscanseq-1)*$deltal+$dgrid)/($nscanseq*$deltal);
$dta = $tsys/$etaq/sqrt(1000.0*$bandw)*sqrt(1./$tcellon+1./$tcelloff);

# printf("----------------------------------------------------------------\n");

printf("--- Summary of parameters of your observation ---\n");
if( $betype== 1){
    printf("Backend type                                           : MAC\n");
}
else{
    printf("Backend type                                           : WHSF\n");
}
printf("Length of mapping area (along the scans)    l1 [arcsec]: %.2f\n", $len1);
printf("Length of mapping area (perp. to the scans) l2 [arcsec]: %.2f\n", $len2);
printf("Time for scan                                 tscan [s]: %.2f\n", $tscan);
printf("Number of ONs per OFF                        Nscan(SEQ): %d\n", $nscanseq);
printf("Separation between scans              (delta)l [arcsec]: %.2f\n", $deltal);
printf("Map grid                                     d [arcsec]: %.2f\n", $dgrid);
printf("System noise temperature                       Tsys [K]: %.2f\n", $tsys);
printf("Resolution bandwidth                            B [kHz]: %.3f\n", $bandw);
printf("Scan speed (%0.1f\" per %0.1fs sample)               [\"/sec]: %.1f\n", $vscan*$tdump,$tdump,$vscan);
printf("Effective integrtion time of ON                   [sec]: %0.2f\n",$tcellon);
printf("Effective integrtion time of OFF                  [sec]: %0.2f\n",$tcelloff);
printf("Overhead time per one scan                        [sec]: %0.1f\n", $toh);
printf("Total on-souce time                               [min]: %.1f\n",$tontot/60.);
printf("Total time per one map                            [min]: %.1f\n", $tobstot/60.);
printf("Observing efficiency eta(ON/OBS)                       : %.2f\n", $tontot/$tobstot);
printf("Optimal OFF-point integration time                [sec]: %0.1f -> %d\n", $toff, $toff);
printf("Rms noise temperature of one map                    [K]: %.3f\n", $dta);

if ( $ARGV[0] eq "tex"){

    printf("--- example for technical justification ---\n");
    printf("\\begin{table}[tbh]\n");
    printf("\\begin{center}\n");
    printf("\\caption[]{\\em{Here we show results of OTF sensitivity estimation.}}\n");
    printf("\\begin{tabular}{cc}\n");
    printf("\\hline \\ \bnoalign {\\smallskip}\n");
    printf("Parameters & Values \\\\\n");
    printf("\\hline \\ \bnoalign {\\smallskip}\n");
    if( $betype== 1){
	printf("Spectrometer &  MAC \\\\\n");
    }
    else{
	printf("Spectrometer &  WHSF \\\\\n");
    }
    printf("Mapping area & %.2f x %.2f \\\\\n", $len1, $len2);
    printf("Time of scan & %.2f [sec] \\\\\n", $tscan);
    printf("Non per OFF & %d \\\\\n", $nscanseq);
    printf("Separation/Grid  & %.2f/%.2f [arcsec] \\\\\n", $deltal, $dgrid);
    printf("Tsys  & %.2f [K] \\\\\n", $tsys);
    printf("Resolution bandwidth & %.3f [kHz]\\\\\n", $bandw);
    printf("Total time &  %.1f [min] \\\\\n", $tobstot/60.);
    printf("Rms noise & %.3f [K] \\\\\n", $dta);
    printf("\\hline \\noalign {\\smallskip}\n");
    printf("\\end{tabular}\n");
    printf("\\end{center}\n");
    printf("\\end{table}\n");
    printf("\n")
}