IMPACT Report SSMO Receiving Review– January 23, 2007

Instrument Status – Boom Suite

• MAG is operating well. The MAG offset is larger than expected and changes with time – but can be corrected on ground.

• SWEA is nominal.• STE-D units are operating well.• STE-U units are unusable. They are light saturated

(Ahead when door is open, Behind both when door is open and closed). Offset maneuvers performed specifically for STE-U and for other reasons verify that saturation varies with offpoint angle in a complex way. We are working with the test unit and the data from the offpoints to understand how exactly this is happening.

Instrument Status – SEP Suite

• LET is operating well. Minor software problems have been found and are being worked by the LET group. However, these problems are not affecting the quality of LET’s science data.

• HET is nominal.• SEPT is nominal.• SIT Ahead is nominal. SIT Behind is ramping up

its high voltage this week and should be operational by Friday, Jan 26.

Ground Systems Status

Operations

• IMPACT has two POC’s (primary at UCB, backup at APL). During commissioning both have been used extensively but will revert to Berkeley POC after SEP group finished commissioning.

• POC software is running nominally. Capable of sending real-time and time-tagged commands.

• POC software engineer Mike Hashii is now our IMPACT operations backup

Status of IMPACT Data Products

• Beacon– Produced at SSC (GSFC)– Uses NOAA antenna partners for 24/7 space weather monitoring– First version of processing software delivered to SSC for Mission Sim 3. Expect major revision shortly.

• L1– Produced at UCB after validation by instrument teams– Highest time resolution data in physical units of all measured quantities– Available in variety of formats (CDF, ASCII, FITS, …)– Reside natively in ISTP-compliant CDF’s (Data Files being produced for MAG, SWEA, STE, LET. Processing software for HET, SIT and SEPT

submitted and undergoing internal testing and integration with processing suite. Verified MAG data ready to be released this week with LET soon to follow. Other instruments are still performing commissioning and calibration and expect public release in February.)

• L2– Produced at UCLA– Key parameter (1-minute cadence) data in physical units– Includes PLASTIC and SWAVES– Available in ASCII (NOT YET AVAILABLE – expected implementation in 2 to 3 weeks)

• L3– Produced at UCLA– Higher level products such as event lists– ASCII (NOT YET AVAILABLE – expected implementation in 4 to 6 weeks)

Still to Be Done

• Continue investigation and monitoring of STE-U to understand what happened – light problem does not jeopardize Level 1 science

• SIT HV to be ramped up this week• SWEA data processing software and verification

to be completed with offset-corrected MAG data• Data processing software integration needs

finishing and final calibrations determined

Where to Get IMPACT Data

• L0 and L1 data online at: http://stereo.ssl.berkeley.edu

• SEP-specific data at: http://www.srl.caltech.edu/STEREO/index.html

• MAG-specific data at: http://www-ssc.igpp.ucla.edu/forms/stereo/index

• Level 2 data available through UCLA (website to broadcast soon)

• Email me with any comments, problems or suggestions at: peters@ssl.berkeley.edu

STE-U Backup Slides

STE Locations

Ahead Spacecraft

SWEASTE-D

MAG

STE-U

IMPACT Boom

STE-U STE-D

The STE units are sensitive to light

• Above ~1E-5 Suns it saturates (moonlight is not bright enough to saturate it, but earthlight)

– With the door closed the unit works OK in room light, but is not perfectly sealed

• Saturation starts with increasing reset rates until at ~1000 resets/second the dead time due to reset paralyzes the system and no events are counted. The front end electronics current also starts to rise significantly at this point

• The STE instrument apertures are not sunlit and there is nothing in the STE FOV that can scatter light into the instrument, so sunlight takes at least 2 bounces to get onto the detector

• A simple scattered light analysis indicated we should be OK– STE-U-A was the biggest concern as there are a number of objects that can

scatter light onto the front of the instrument (though not directly into the aperture).

– STE-U-B has fewer items that can scatter light onto the front of the instrument

– Note that the sun-shades on the STE-U unit are outside the FOV

– STE-D units are in the dark and pointing away from the spacecraft.

STE-U-A

STE-U-B

STE-U-A

STE-U-B

Closeout Pictures

ETU STE Tests on the ground• Testing ETU STE on the ground with calibrated light source to

attempt to replicate what we see on orbit with STE-U (door closed)

• Results indicate a significant light leak for STE-U-B

ETU STE Light Sensitivity (door closed)

1

10

100

1000

10000

0.1 1 10 100 1000

kLux on door

c/s

, m

A

Avg Reset rate, counter

Avg Reset Rate, Scope

HKP FE Current

FE Current - Dark Current

Room Light

Sunlight

STE-U-B

STE-U-A

Sample STE-D-B Results