Observing time estimates for the OSO 20 m telescope


The time estimate includes time spent on the reference position (Position and Beam Switching) or the reference phase (Frequency Switching) excluding overheads. Add 15% on top of the calculated time for calibrations, pointing, antenna slewing and data handling. Projects requiring frequent frequency changes of the SIS-receiver should allow 15 minutes for each tuning. Frequency changes within each of the three HEMT receiver bands below 50 GHz are instantaneous; OSO staff members are required to change between bands. Such changes take about 30 minutes and are done daytime. Changes within and between the 3 and 4 mm bands are instantaneous.
      Note that the default temperature scale is in T*A units. To use the main beam brightness temperature scale (TMB) enter the required sensitivity divided by the main beam efficiency.
      Simultaneous observations of two polarisation components are possible for all receiver bands except the range 26-36 GHz (LCP/RCP for the 7 mm, 1.0 cm and 1.3 cm bands, and H/V for the 3 and 4 mm bands), Note that the calculated time applies to a single polarisation, i.e., divide the calculated time by a factor of 2 if two polarisation channels can be co-averaged in the data analysis (e.g. if the sought signal is unpolarised).


PropertyValueUnitDescription
PSW-Position Switching
FSW-Frequency Switching
BSW-Beam Switching
Frequency[GHz]Line frequency
Resolution[kHz]Frequency resolution
Elevation[deg]Typical elevation
Sensitivity[K]Sensitivity (r.m.s.)
Submit values-Calculates the observation time