Write LFCs to Antenna FITS File Header

Modification Request #2 (C1 2006)

1. Introduction

The antenna secondary optics servos command servo commands are derived from the following quantities:

local_focus_correction(six axes)
dynamic corrections (Y axis only)
focus tracking model coefficients (3 per axis, six axes)
subreflector commands (scan-segment, six axes)

Currently, only the dynamic corrections and focus tracking coefficients for the Y-axis are stored in the antenna FITS file. This MR adds the local focus correction and focus tracking model coefficients to the antenna primary header. Additionally, it expands the field widths to fully represent the quantities.

2. Requirements

Add the local focus corrections for all six axes to the antenna primary header
Add the focus tracking model coefficients for all six axes to the antenna primary header
Increase the data-field widths to show the full accuracy of the values for the focus tracking and local focus correction keywords.
Increment the FITS version number to denote a change in format.

3. Design

It would be very useful to have the local focus corrections (LFCs) written to the Antenna Fits file header. There are six LFC quantities:

Manager Parameter Name	FITS Header Keyword	Comment
local_focus_correction,X	LFC_X	X axis local focus offset
local_focus_correction,Y	LFC_Y	Y axis local focus offset
local_focus_correction,Z	LFC_Z	Z axis local focus offset
local_focus_correction,Xt	LFC_XT	X axis tilt focus offset
local_focus_correction,Yt	LFC_YT	Y axis tilt focus offset
local_focus_correction,Zt	LFC_ZT	Z axis tilt focus offset

The focus tracking model coefficients are labelled as 'A', 'B', and 'C' for each of the six axes. The actual offset generated in derived from the model:

$\delta = \bold{A} + \bold{B}\cos(el) + \bold{C}\sin(el)$

Where: A,B and C are the model coefficients, and $\delta$ is the resulting offset added to the focus servo command.

Manager Parameter Name	FITS Header Keyword	Comment
focus_tracking_model,X_A	FTRKXDA	X axis focus tracking A
focus_tracking_model,X_B	FTRKXDB	X axis focus tracking B
focus_tracking_model,X_C	FTRKXDC	X axis focus tracking C
focus_tracking_model,Y_A	FTRKYDA¹	Y axis focus tracking A
focus_tracking_model,Y_B	FTRKYDB¹	Y axis focus tracking B
focus_tracking_model,Y_C	FTRKYDC¹	Y axis focus tracking C
focus_tracking_model,Z_A	FTRKZDA	Z axis focus tracking A
focus_tracking_model,Z_B	FTRKZDB	Z axis focus tracking B
focus_tracking_model,Z_C	FTRKZDC	Z axis focus tracking C
focus_tracking_model,Xt_A	FTRKXTA	X axis tilt focus tracking A
focus_tracking_model,Xt_B	FTRKXTB	X axis tilt focus tracking B
focus_tracking_model,Xt_C	FTRKXTC	X axis tilt focus tracking C
focus_tracking_model,Yt_A	FTRKYTA	Y axis tilt focus tracking A
focus_tracking_model,Yt_B	FTRKYTB	Y axis tilt focus tracking B
focus_tracking_model,Yt_C	FTRKYTC	Y axis tilt focus tracking C
focus_tracking_model,Zt_A	FTRKZTA	Z axis tilt focus tracking A
focus_tracking_model,Zt_B	FTRKZTB	Z axis tilt focus tracking B
focus_tracking_model,Zt_C	FTRKZTC	Z axis tilt focus tracking C

Notes: ¹ Currently exists in Antenna FITS file.

3. Deployment Checklist

Communication with Computing group needed? - No.
What documentation needs to be updated? - Update Antenna FITS file specification.
Training Needed? Is this being released to staff astronomers or everyone right now? No training required. Community-wide release.
Notification Needed? - Contact filler module owners to notify them of a change in FITS version.

4. Test Plan

Use CLEO to manually change the LFCs and then take some data. Compare FITS file information with the CLEO inputs.
Make several focus observations and make sure the LFC determined by GFM are correctly written into the FITS files.
Take data and directly compare the focus tracking and pointing model numbers recorded in the FITS file with the PFM database.

Signatures

APPROVED: I acknowledge that my request is fully contained in this MR, and if the SDD delivers exactly what I specified, I will be happy.

ACCEPTED: I acknowledge that I have validated the completed code according to the acceptance tests, and I am happy with the results.

Written	- JoeBrandt - 20 Feb 2006
Checked	- RamonCreager - 23 Feb 2006
Approved by Sponsor	- DanaBalser - 14 Feb 2006
Approved by CCC	- JohnFord - 10 Apr 2006
Accepted/Delivered by Sponsor	- DanaBalser - 23 Mar 2006

Symbols:

Use %X% if MR is not complete (will display )
Use %Y% if MR iscomplete (will display )

-- NicoleRadziwill - 14 Feb 2006

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