Atacama Pathfinder EXperiment APEX
Observing time calculator
MPIfR Bonn   ESO   Onsala Space Observatory

Home > Instrumentation > Heterodyne Instruments > Observing time calculator > Calculator ON/OFF Integration Time Estimator

ON/OFF Integration time estimator V6.0.1
Use this calculator for on-off observations. If you are planning on-the-fly mapping, you should instead use the dedicated OTF Calculator

The (average) elevation of the source, the receiver temperature, required σ (in K), and the spectral resolution, the on-source integration time can be estimated.

System overheads include telescope movements, software overheads, observing mode efficiency, etc. Setup + calibration overheads include source acquisition, pointing, focus, receiver tuning and calibration scans. Note about overheads.

For an overview of the atmospheric transmission and the possible backend configurations for each receiver, check our atmospheric transmission tool.
Heterodyne receiver:
Tunning Freq: [GHz]
Line Freq: [GHz]
Side Band:
Full resolution Δv [ channels] : [km/s]
Manual resolution Δv: [km/s]
pwv : [mm H2O]
Source elevation: [deg]
rms : [K]
Tau (source elev deg) 122232.767
Trec [K] 80.5
Tsys [K] (source elev deg) INF
TsysImage [K] (source elev deg) 80.5
Beam [arcsec] 18.1
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]

2017-09-06New version 6.0.1, Fix a bug in off time estimation for V6.0
2017-08-30New version 6.0 available. New set of overhead parameters per instrument, measured from data obtained in 2016
2017-08-30SEPIA-B7 added, The specification values for SEPIA-B7 are provisional (based on the specifications) and will need to be updated after successful installation and commissioning