looreo.blogg.se - Frequency resolution calculator

#Frequency resolution calculator software

Apart from that, the values proposed for the measuring range and the scaling of the axes (important for analogue and graphical representations) and the number of significant decimal positions (important for digital and tabulated representations) have to be adapted to individual requirements. In this case, the corresponding Greek letter will be displayed (otherwise the Latin letter will be displayed). This symbol should consist of as few (meaningful) letters as possible and may also consist of the & character followed by a letter. The new quantity must contain a symbol with which it can be addressed. New generates a new (data) record which begins with the name of the quantity. If you need to include these quantities in a table or diagram, you must define these quantities here. Some quantities cannot be measured directly using CASSY, and are thus not available as a CASSY channel. The Tool is built by the Proposal and Observing Preparation System team within the ALMA Computing IPT.Open topic with navigation Calculator settings

#Frequency resolution calculator software

The Observing Tool is the software tool that will be used for the preparation of ALMA Observing Projects. This web application was adapted from the ALMA Sensitivity Calculator in the ALMA Observing Tool by Mark Nicol. We are particularly interested to hear about any undesirable behaviour and bugs as well as any improvements that you would like to see. Choosing the unit "Kelvin" will cause the ASC to use surface brightness units and will thus require that an angular resolution be entered.Īny questions about the ASC should be addressed to the Helpdesk (registration required).

Sensitivity/Integration Time: One of these quantities needs to be specified in order to calculate the other.

Resolution: A value should be entered here if the user is interested in surface brightness sensitivity.

Number of Antennas: The ASC currently defaults to 43 12-m array, 10 7-m array and 3 TP array antennas.

See the Weather page for further information on weather statistics and atmospheric transmission. Note though that the OT will always use the automatically-chosen option when calculating a project's estimate time. Alternatively, the user may override this with their own choice.

Water Vapour Column Density: The "Automatic Choice" option will select an appropriate value according to the input frequency.

For spectral line observations, the width of the resolution element in which the user is interested should be entered.

Bandwidth Per Polarization: 7.5 GHz should be selected for continuum observations in Bands 1-8 and 15 GHz in Bands 9 and 10.

However, Band 5 is actually more sensitive in this region and the Observing Tool will force the selection of this band. As the ASC only uses band averages for the receiver temperatures, Band 4 appears to be the superior receiver.

Observing Band: This is usually chosen automatically, but in the overlap region between Bands 4 and 5 (158-163 GHz) the user can select.

Bands 1 and 2 will become part of ALMA as part of a future development plan.

Observing Frequency: This must be set within the boundaries of ALMA bands 1 to 10 the eight bands available for science observations are highlighted below.

Users will usually want "Dual" for continuum and for spectral line modes not requiring the highest spectral resolution modes.

Single Polarization allows for very high spectral resolution at the cost of sensitivity. Polarization: There are two options: "Single" and "Dual".In order for the ASC to work, your browser must have JavaScript enabled. The effects of shadowing are not taken into account.planets or the Sun, will be underestimated The ASC is not able to add the source contribution to the system temperature and therefore the times for particularly bright sources e.g.For DSB receivers (B9 and 10) the contribution to the system temperature from the image sideband is assumed to be twice that in the signal sideband.Integration times refer only to the on-source time (no overheads are taken into account).Please be aware of the following limitations: This allows users to prepare for future Cycles. the maximum number of allowed antennas for the 12-m array is 50 and the highest resolution must not exceed that corresponding to a maximum baseline of 16 km. The ASC has been configured so that inputs are allowed that conform to the final design specification of ALMA e.g. Input and output parameters are explained below, but for an in-depth explanation of how the ASC works, please consult Chapter 9 of the ALMA Technical Handbook. The ALMA Sensitivity Calculator (ASC) will calculate the necessary integration times for a given sensitivity (or vice versa) for your ALMA observing project.