Atacama Pathfinder EXperiment APEX
Observing time calculator
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Home > Instrumentation > Heterodyne Instruments > Observing time calculator > Calculator ON/OFF Integration Time Estimator

Use this calculator for on-off observations. If you are planning on-the-fly mapping, you should instead use the dedicated OTF Calculator

ON/OFF Integration time estimator
The (average) elevation of the source, the receiver temperature, required σ (in K), and the spectral re- solution, the on-source integration time can be es- timated. Also the total time is calculated assuming toff=ton and a system observing efficiency of 0.4, i.e. ttotal=(ton + toff)/0.4.The system efficiency takes into account both system and setup+calibration over- heads.
System overheads include telescope movements, software overheads, observing mode efficiency, etc. Setup + calibration overheads include source acquisition, pointing, focus, receiver tuning and calibration scans.
Heterodyne receiver:
Frequency: [GHz]
Full resolution Δv [ channels] : [km/s]
Manual resolution Δv: [km/s]
Redshift z:
Sky Frequency: [GHz]
pwv : [mm H2O]
Source elevation: [deg]
rms : [K]
Tau (source elev deg) INF
Trec [K] 49.5
Tsys [K] (source elev deg) 64.3
Beam [arcsec] 0
Position Switching On time 0.000 [s]
Total Position Switching time 0.000 [s]
Beam Switching On time 0.000 [s]
Total Beam Switching time 0.000 [s]
RMS Calculator
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Last update: June 15th, 2016