VLBA Testing and Support – March 17, 2004


VLBA Antenna and Site Electronics Performance

Test

People

Priority

Status

Comments

Dates

Pointing Improvements

Brisken,

Walker

Medium

Inactive

Pointing model, other

improvements


S/X dichroic performance

?

Low

Inactive

Determine cause of excess spillover at medium elevations- not fixable


Spurious signals
(internal or external RFI)

Various

Medium

Inactive


Look for spurious signals, develop monitoring/testing techniques


90/50 performance

?

Low

Inactive

Try to improve 90/50cm performance


Codes in dates: R= report, C= completion, T= target for testing, etc.

Calibration

Test

People

Priority

Status

Comments

Dates

Flux/Polarization Calibrators

Myers, Taylor

High

Ongoing

Handoff to Operations

C

2003

Apr.

Alternate EVPA calibration methods

Zavala, Taylor

Low

Inactive

Compare methods and pursue most promising


Compile and Post VLBA Leakage Terms

Myers, Taylor

Low

Inactive


taking contributions


Improve phase referencing

Fomalont, Mioduszewski

High

Ongoing


Develop algorithms,

implement in AIPS


Service Calibration

Sjouwerman

Must

Ongoing

Pass off to

operations


Ionoshperic Astrometric

Calibration

Brisken

Medium

Inactive

Develop software in

aips++


Codes in dates: R= report, C= completion, T= target for testing, etc.

SCHED/AIPS/AIPS++

Test

People

Priority

Status

Comments

Dates

Sched

Walker

High

Ongoing



VLBI reduction capability

AIPS++

Low

Ongoing

aips++ group is concentrating on EVLA reduction first


Multi-Freq. Synthesis

?

Medium

Inactive

Needs software effort


Codes in dates: R= report, C= completion, T= target for testing, etc.


High Frequency

Test

People

Priority

Status

Comments

Dates

3mm Pointing,

calibration,

Walker,Ruff

Brisken

High

Ongoing

check pointing terms

calibration, etc.


Rotation variation parms


Dhawan

High

Ongoing

Determine rotation variation of FRM
for 3mm


Holography

and

Subreflector improvements

Dhawan, Revnell, Thunborg

Must

Ongoing

Resurfacing

Completed at PT

C
2004

Feb.

Reset Panels at PT

Redo Holography

Thunborg,

Dhawan et al.

Must

Ongoing

Planned

T

2004

Apr.

Codes in dates: R= report, C= completion, T= target for testing, etc.

Operations and System Parameters

Test

People

Priority

Status

Comments

Dates

7mm and 3mm performance

issues

Wurnig, Dhawan

High

Routine

Measure/check pointing, gain curves, FRM, etc.

as needed

Real Time fringe checks

Clark

Low

Inactive


Fix problems with real time test


Codes in dates: R= report, C= completion, T= target for testing, etc.

Recording System

Test

People

Priority

Status

Comments

Dates

Mark 5

Haystack

Durand,

Romney, Brisken

Must

Ongoing

Test Mark5A, Develop

VLBA interface


C

2003

Oct.

Codes in dates: R= report, C= completion, T= target for testing, etc.

Correlator Performance

Test

People

Priority

Status

Comments

Dates

Pulsar Gating

Benson

Medium

Inactive

Write analyst handbook, other documentation


Spectral dynamic 
range

Romney

Medium

Inactive

Test VLBA correlator in the presence of strong lines


Fast sync

Romney

Low

Inactive

Test/improve sync time


Mapping functions

Benson

Medium

Inactive

Bar. pressure


Mk IV

Romney

Low

Inactive

MkIV header blanking

waiting on programmer


Codes in dates: R= report, C= completion, T= target for testing, etc

Non-VLBA Stations

Test

People

Priority

Status

Comments

Dates

GBT

Romney, van Buskirk

High

Ongoing

workable system but not yet smooth


Arecibo

Romney

Medium

Ongoing

workable system but not yet smooth


Globals

?

Low

Inactive

Streamline interface from EVN to VLBA, calibration transfer


Codes in dates: R= report, C= completion, T= target for testing, etc.

Miscellaneous Projects

Test

People

Priority

Status

Comments

Dates

Spacecraft localization for navigation

Romney, Dhawan

High

Ongoing

Preliminary test complete,

others planned


Move LA

Ulvestad

High

Negotiating

Probably have to move

LA by 2006

JU

date

Student Grant Program

Ulvestad, Taylor, Wrobel

Must

Find $$$

Plan and announce

JU

date

Codes in dates: R= report, C= completion, T= target for testing, etc.


Items completed June 2000 onwards:

Phase referencing documentation (Wrobel) – 2000 June

Polarization labeling (Flatters) – 2000 July

CMVA Gains/calibration (Dhawan/Bower) – 2000 August

Rail Heights applied (Walker) – 2000 September

Report on Flux/Polarization Cals. – 2000 September (ongoing )

PT link project observing begins – 2000 October

Performance test of Kepler(Benson) – 2000 December

3mm Hot/Cold Load tests complete (Dhawan) – 2001 February

Phase reference positions (Fomalont) – 2001 July

AIPS simplified front end (Ulvestad) – 2001 July

Using GPS for calibration (Walker) – 2001 July

512 Mbps (Romney/Durand) - 2001 July

Rebuild of OMS (Moeser) – 2001 December

FRING/KRING testing (Mioduszewski) – 2002 April

Astrometry on new calibrators (Fomalont) – 2002 July

VLBI redution scripts (Mioduszewski) – 2002 August

Encoder Improvements (Brisken et al) – 2002 November

3mm receiver checkout (Dhawan) – 2002 November

Recorder/Formatter test procedures (Durand/Rowen) – 2002 November

Autorelease (Sjouwerman) – 2003 July

VLBA Data rate increased to 1 Mbps (Romney) – 2003 August?

Calibration Transfer for VLA (Sjouwerman) – 2003 October

Calibration Transfer for GBT (Sjouwerman) – 2003 November