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The WEAVE Automated Submission Platform (WASP) automatically emails the principal investigators (PIs) with submission deadlines, validation acknowledgements and any other important information concerning the preparation of phase 2. The first two emails contain the following (the subject line is provided):

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emails contains the credentials to log onto WASP. Subject line is:

^{Subject: [WEAVE] Account created for WEAVE observation preparation}

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A following email contains information about the opening of the OB submission window:

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General assistance can be provided at the following emailemailing:

Phase 2: A short guide

The purpose of the phase 2 is the upload of a FITS catalog containing fiber positions on sky, and observing blocks (OB) written in XML describing the necessary observations to the submission platform WASP, maintained by CASU in Cambrige (IoA). At the beginning of every trimester, the uploaded, validated and selected OBs are ingested into the observing queue at the WHT.

The kick off of phase 2 is a simple catalog of targets in CSV format prepared by the PI following the instructions provided on this page. ING can provide assistance with the preparation of the aforementioned catalog, and afterwards ING can also process it to make the FITS catalog and the XML OBs, and eventually upload to and validate on WASP on behalf of the PI.

An XML OB contains the instructions to execute the observations: instrument setup, telescope pointing, guiding star, dithering, exposure times, observing constraints and calibrations (one lamp flat and two arcs, before and after the science exposures). The following is an example of the XML code of an OB with comments for users: WC_2023A1-lifu_01-tgcs.xml.

Every observed OB is reduced and calibrated using automatic pipelines at CASU (IoA, Cambridge). Data is flux calibrated using a standard sens functions. However, applicant scan submit their own OBs for observing flux standards along with the science OBs. Every trimester we accept a maximum of 100 OBs  per programme.

Below we provide an example of real observations made from a simple OB which consists of 3 exposures 1020s each following a 3-point dithering pattern in LIFU low-resolution mode and arbitrary position angle: 

PROGTEMP, OBSTEMP: use the OBSTEMP and the PROGTEMP builders to generate them.

IFU_DITHER: it is set to 0 if not specified (no dithering). Standard dithering patterns for 3, 4, 5 and 6 points are available for selection (read more information on IFU_DITHER below).

The position angle (PA, as measured from North to East) is automatically set to 180º, for declinations North to 28.7º, and to 0º, for declinations South to 28.7º. Note that these PAs could be slightly different to allow for finding a suitable acquisition and guiding star. For any other PAs, read more information on requested PA below. Not all values are posible given the rotator limits, and similarly to the above, it can change for finding a suitable acquisition and guiding star.

CSV catalog:

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^{TARGID,TARGNAME,GAIA_RA,GAIA_DEC,PROGTEMP,OBSTEMP,IFU_DITHER
NGC3158,NGC3158,153.460497,38.764898,41331,NBCEB,3}

Validated FITS catalog on WASP:  WS2022A2-002.fits

Validated XML OB on WASP and ready for ingestion into the observing queue: 1713807920_1.xml

Log entry as a result fo the execution of the above OB. Note that the target coordinates correspond to the center of the field of view, not the centre of the LIFU array.

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ING takes biases every night and twilight sky flats regularly. If you need these sets of calibrations when working with your data, please contact ING.

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Phase 2: the short guide

https://ingpublic.atlassian.net/wiki/pages/createpage.action?spaceKey=ING&title=WEAVE%20Open-Time%20Phase%202%3A%20The%20Short%20Guide

LIFU mode: catalogue preparation

Target declination and right ascension limits

The current target declination limit is -25º. Objects with a declination lower than that cannot be observed. 

WASP sets limits to allowed target RA and Dec, and it will not validate your OB if your target coordinates lie outside the limits for that the trimester. See below the allowed RAs RA ranges for each trimester.

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Please use this exposure time calculator for your signal-to-noise calculations: https://a.ing.iac.es/signalWEAVE/. There is more information, including a downloadable version, at WEAVE Exposure Time Calculator .

Instrument configuration

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IFU_PA_REQUEST allows the catalogue provider to specify a rotation angle (position angle) of the LIFU, if this is required.  Any dithering requested for the field is applied to the rotated LIFU frame.  If a specific PA value is not requested, then the following defaults are applied: IFU_PA=0° (for declinations lower than 28.7°) and IFU_PA=180° (for declinations higher than 28.7°). Note that the requested IFU_PA could be changed by the IFU workflow software if a suitable guiding star cannot be found at the requested PA. Below it's a plot which shows how the PA is changed to find a suitable guiding star (from the requested PA marked as a blue cross to the final PA marked as a black cross).

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The table below shows the allowed values for the PA depending on minimum elevation requested in the OB and the target’s declination. Following are plots showing two cases, for better understanding of the PA ranges in the table.

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IFU_DITHER allows the PI to specify the dithering strategy for their observations, but may alternatively request not to dither their observations, with the understanding that this will not provide full spatial coverage of their requested field. PIs may request the preset -3, 3, 4, 5 and 6-dither patterns. The LIFU preset patterns will be properly rotated according to the position angle of the observation. 

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For custom dither patterns, constraints on the dither step size are imposed by the WASP to ensure that the guide star remains within the guiding camera field of view. From the perspective of IFU users, careful consideration of the dithering options should be made. Below it's an example of custom dithering. Note that pointings are provided for each dither, rather than the dither pointings from an initial position. The three pointings provided in the example below would be executed as part of one only dither, rather than the dither pointings from an initial position. The three pointings provided in the example below would be executed as part of one only OB. Note that TARGID must be equal to TARGNAME in every row. The maximum allowed distance between (consecutive, for instance, exposure order 4 and 5) dither points is 4 arcsec while the maximum overall dither distance across all dithers can exceed the maximum permitted dither 10 arcsec. Minimum distance is ~0.3 arcsec. Dither point positions cannot be repeated within an OB.

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Aladin overlays of the LIFU footprints

Aladin overlays can be useful for preparing your observations. To use the Aladin overlays below, follow these instructions:

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