starflats with obstac

Table of Contents

• 1 Introduction

• 2 Define a starflat grid

• 3 Create a tiling

• 4 Fill the queue with observations

• 5 Download the queue contents as a TSV

• 6 Observe with SISPI

• 7 Supplement the TSV file with results of the exposures

• 8 Upload the modified TSV file to obstac

1 Introduction

This version of the instructions apply when SISPI does not automatically execute observations on the queue, but rather follows a text file

Performing a precam starflat grid test has the following stages:

• 1. Define the grid

  2. Create a tiling of that grid

  3. Fill the queue with a observations

  4. Download the TSV file containg the contents of the queue

  5. Feed the TSV file to SISPI for observation

  6. Modify the TSV file to include the exposure ID and the "mountian done" value

  7. Upload the modified TSV file to obstac for inclusion in the exposure table

2 Define a starflat grid

Each starflat grid consists of a collection of hexes. Unlike hexes for other programs, obstac does not create these hexes when initializing its database. Instead, observers create them as desired.

Starting at obstac's precam homepage: http://localhost:8090/html/precam.html, scroll down to the sections entitled "Fill the queue (starflat)", and follow the link on the end of the first sentence, "Select or create a starflat grid here."

This brings up this page: http://localhost:8090/precam_{starflatgrids} which shows a table of grids that have already been defined, and a form for creating a new tiling. The forms of the field have the following meanings:

RA

the RA of the center of the grid in decimal degrees

Decl

the declination of the center of the grid in decimal degrees

#RA

the number of columns (positions in RA) in the grid

#Decl

the number of rows (positions in Dec) in the grid

Spacing

the separation between rows (and columns) in arcseconds.

Currently, the same spacing is always used for RA and declination. Create the grid using the "Add" button, and your new grid will appear in the table.

3 Create a tiling

A tiling is a single set of exposures on a grid, where a set is one exposure for hex for each filter. So, if you want to observe a grid twice in each filter, you should create two tilings.

Each precam starflat tiling corresponds to a single grid, so the tiling id alone is sufficient to uniquely identify a set of starflat grid observations; the grid id is not necessary.

To create a new tiling, go to the "Precam starflat grids" page: http://localhost:8090/precam_{starflatgrids} Note that the far right hand column of the table of grids is a set of "tilings" links. Follow that link for the row of the grid you want to create a tiling for.

This link will take you to the "Precam starflat tilings" page. If you know the grid id, you can go directly. For example, for a grid id of 5, the URL is http://localhost:8090/precam_starflat_tilings?grid_id=5

This page begins with a table of the existing tilings for the grid. To add a tiling, use the "add tiling" button; there is no other form to fill out.

4 Fill the queue with observations

If you want the queue to start with your grid, you must first empty the queue. Go the the queue page: http://localhost:8090/obs_queue?program=5 (also linked to from the second section of the obstac procam homepage), and hit the "Empty" button at the bottom of the page.

Once you have created a tiling to observe, it can be added to the queue. On the "Precam starflat tilings" page, there is a form for just that after the table of tilings.

Check the tiling you wish to observe in the list of tilings, fill out the form, and hit "Fill the queue". The queue will not fill instantly; go to the queue page, and refresh it a few times until new exposures stop appearing.

5 Download the queue contents as a TSV

After the table of observains in the queue on the queue page, in the section entitled "Text list," there is a link to the file with the contents of the queue as a TSV file. Hit the link, and save the file on local disk somewhere.

6 Observe with SISPI

The script that consumes the TSV file and performs the observation is outside obstac's scope. Appropriate instructions should be added here as they become available.

7 Supplement the TSV file with results of the exposures

Once the observations have been completed, obstac's exposure tables need to be update. Obstac can ingest a TSV file in a format similar to the one it produced, but two additional columns are needed: one with the exposure ID, and another with the "mountain done" state.

So, if the TSV file produced by obstac looked like this:

4.72834674039 0.65 i 65.0 precam5_6 2010-11-20T02:38:12Z 2010-11-20T04:43:51Z 1.26512217523 sci

4.72834674039 0.65 i 65.0 precam5_6 2010-11-20T02:38:12Z 2010-11-20T04:43:51Z 1.26512217523 sci

and the exposure IDs for the exposures were 101 and 102, and the first succeeded and the second failed, then the file to upload back into obstac should look like this:

4.72834674039 0.65 i 65.0 precam5_6 2010-11-20T02:38:12Z 2010-11-20T04:43:51Z 1.26512217523 sci 101 DONE

4.72834674039 0.65 i 65.0 precam5_6 2010-11-20T02:38:12Z 2010-11-20T04:43:51Z 1.26512217523 sci 102 UNDONE

In other words, the new colums should look like this:

101 DONE

102 FAILED

8 Upload the modified TSV file to obstac

This step is only necessary when obstac does not automatically synchronize its exposure table with that supplied by SISPI.

Near the end of the precam obstac homepage, there is a section entitled "Add completed exposures to the ObsTac database (from a file)."

Fill in the filename, and hit "Upload" to update obstac's exposure database.

You can verify the contents of obstac's exposure database using the form in the "See completed hexes" section of the precam obstac homepage.

Author: Eric H. Neilsen, Jr.

Date: November 21, 2010

HTML generated by org-mode 7.01 in emacs 23