Setup:

The rfi coming from the VC exhibits was measured at the VC using:

anritsu spectrum analyzer
6 foot bnc cable.
efld,bfld (large and small) probes, lband helix

Dates for data:

14APR16: dana, daun, and phil

measured globe, crater machine, atm display, track an asteroid.
datalocation:x101/160414/160414

27APR16: phil

measured track a crater (kinect) at lband (14APR16 was just 0-1ghz)
datalocation:x101/160414/160427

06may16: felix, phil

upstairs exhibits, arecibo telescope mockup.
datalocation:x101/160414/160506

09may16:phil

measure kinect at lband
datalocation:x101/160414/160509

Table of measurements done:

The table below lists the measurements that were stored on the anritsu.

file	ant	measurement	date	notes
Omni globe
		cpu, display screen globe, projector for globe positions: at cpu, and then at globe.
49	lb	cpu on, globe off	160414	at cpu
50	lb	all off		at cpu
58	lb	all off		at globe
59	lb	globe on, cpu off		at globe
60	lb	globe on, cpu on		at globe
61	lb	globe on, cpu on		obsDeck south rail door closed
62	lb	globe on , cpu on		obsDeck south rail door open
63	lb	globe off, cpu off		obsDeck south rail door closed
64	lb	trace A:monOff, cpuOn trace C: monOn,cpuOn		at cpu
75	lb	cpu on	160506	helix 1 meter from cpu, pointed at cpu
76	lb	cpu off	160506	off for rec 75
crater machine
		motor to turn turntable.. this is what we tested. cpu,camera, display screen (not tested) motor to move air gun in ,out..(not tested)
65	eprb	motor on, cpu on	160414	Eprb next to motor
66	eprb	motor off, cpu on		Eprb next to motor
67	eprb	motor on, cpu on zero span		Eprb next to motor
atmospheric radar
		large interactive display screen cpu inside cabinet
68	lb	all on	160414	helix 3 feet from display pointed at display
69	lb	all off		same as above
70	lb	all on (repeat 68)		same as above
Track an asteroid
		cpu in cabinet (8 feet from display) kinect motion tracker projector
49	Bprb	kinect on	160427	large Hprobe perp to kinect window (vertical)
50	Bprb	kinect unplugged,projector still on.		same as above
58	Bprb	all off		same as above
77	lb	all on	160509	lband helix pointed at kinect output window, 1 meter away
78	lb	kinect off	160509	off for rec 77
radio freq in the sky (upstairs)
		3 touch screens, 2 cpu inside exhibit on floor. posA - in front of screen that points toward stairs posD - side of exhibit, door open, between two cpus on the inside
59	lb	all on	160506	posA: helix 1 meter from screen, pointing at screen
60	lb	all on		polD: 1 meter from side door pointed at cpus.
61	lb	all off		posA: off for rec 59
62	lb	all off		posD: off for rec 60
63	Bprb	all off		posA: large loop, vertical, loop perp to screen
64	Bprb	all off		posD: probe vertical between 2 cpus
65	Bprb	all on		posA: on for rec 63
66	Bprb	all on		posD: on fro rec 64
Deep sky detective (upstairs)
		touch screen and cpu under display posA: in front of display posB: next to cpu (under display)
67	Bprb	all on	160506	PosA. large loop, vertical, perp to screen, next to screen
68	Bprb	all on		PosB: next to cpu
69	Bprb	all off		PosA: off for rec 67
70	Bprb	all off		PosB: off for rec 68
71	lbnd	all off		posA: lband helix pointed at screen, 1 meter away
72	lbnd	all on		PosA: on for rec 71.
arecibo telescope model(downstairs)
		motor to turn azimuth motor to move in za motor to move catwalk ? posA: lband helix at plexiglass window, pointed at az,za motors.
73	lbnd	moving azimuth	150506	PosA:lband helix
74	lbnd	no motion	150506	PosA: off for rec 73

Plots of the data

Exhibit	plots	description
Globe	.ps .pdf	We used the lband helix for the measurements. Page 1: 160414 Top: lband helix at cpu (about 3 feet away): black: single trace (no averaging) cpu, globe on red: peak hold (about 30 secs), cpu,globe on green: peak hold, all off There is a comb: 121.92 MHz spacing, includes: 1217.62539 (from hi res measurement) Bottom: helix at globe (about 3 feet from projector). black: single trace (no averaging), cpu, globe on. red: peak hold (30 secs), globe, cpu on green: all off The projector for the globe is not creating much rfi. Page 2: Top: over plot globe cpu rfi 14APR16 and 06may16 Red, green: on,off globe cpu: 14APR16 blue,lightblue: on,off globe cpu: 06may16 helix at visitors deck (at rail) looking bad at exhibits The comb was present on both days the pairs of rfi around: 1150, 1275, 1400, 1750 also repeat on the two days. Bottom: high plot of globe cpu on,off from visitor center balcony the door to the outside balcony was closed The resolution bandwidth was 10 Hz. -152 dbm in 10Hz bandwidth is equivalent to a Tsys of about 4000 Kelvins. The 1217.62539 MHz birdie from the cpu is around -131 dbm (in a 10Hz channel) The spectrum analyzer was free running.. Processing: x101/160414/rfiVc_globe.pro
crater	.ps .pdf	Make a crater display: We used the efield probe placing it next to the motor that turns the turntable top: motor on,off .. spectra red is peak hold (30 secs) with motor on green: peak hold (30 secs) with motor off (cpu is on). this motor makes lots of noise.. it must have brushes Bottom: eprobe at motor, zero span (time domain). the resolution bandwidth was 3MHz centered at 327 MHz The x axis is in milliseconds. It shows when the narrow spikes from the motor occurred. The time resolution is 18usecs. Most of the spikes were not resolved with this time sampling. Processing:x101/160414/rfiVc_crater.pro
atmradar	.ps .pdf	atmospheric radar display lband helix, pointed at monitor (3 feet away). Red: peak hold all on green: peak hold, all off blue:Repeat peak Hold all On... the on rfi repeated. I've flagged some of the stronger peaks. Processing: x101/160414/rfiVc_atm.pro
radarTrack anAsteroid	.ps .pdf	Track and asteroid display.. kinect unit and projector Top: 0 - 1000 MHz large Hfield probe was placed perpendicular to the kinect window Black: peak hold all on red: peak hold, kinect Off, projector still on green: all off rfi below 300 MHz (may be from projector) Bottom: 1000 to 2000 MHz lband helix pointed at kinect window. 1 meter away. Lots of rfi. It might have been sweeping across the band... Processing: x101/160414/rfiVc_trkasteroid.pro
AO model	.ps .pdf	AO telescope model lband helix at plexiglass window. take data with azimuth moving and stopped Lots of rfi from the motor.
Upstairs displays:
RadioSky	.ps .pdf	Radio sky display: 3 interactive monitors, cpus inside display PosA: looking at display facing the stairs PosB: side of display open , looking at cpus. Page 1: lband helix: 1-2 Ghz Top: posA, 3 feet away pointed at display. display on,off Bottom: posB, 3 feet from cpus, pointed at cpus. display on,off Page2: large Bfield loop. 0 to 1 Ghz Top: posA. at Display. Probe vertical, loop Perpendicular to display Bottom: posB: hanging between the 2 cpus 74.198 MHz comb with odd harmonics strongest 1483.6 is the strong comb element in 1-2 ghz (at least using our helix). processing:x101/160414/rfiVc_radioSky.pro
deepSky detective	.ps .pdf	Deep sky detective display. Display and CPU PosA: in front of display PosB; next to cpu. Page 1: 0..1000 MHz large bfield loop Top: probe vertical, loop perpendicular to screen (at screen) Bottom: probe next to cpu. Not much rfi from cpu Page 2: 1000 to 2000 MHz. lband helix helix 3 feet from display flag 73.272 MHz comb.. 1320.7 strongest comb element in lband also flag 149.12 MHz comb (or half that). 1485.4 is strong birdie in lband processing: x101/160414/rfiVc_deepsky.pro

Summary:

Globe:

The cpu at the large globe display has a 121.9 MHz comb through lband

1217.62539 MHz (part of this comb) can be seen (in a 10Hz rbw) from the visitor center balcony (at the rail) with the building door closed
The projector for the globe does not make much rfi

Crater exhibit:

the motor makes lots of rfi... it must have brushes..

Atm radar display:

spikes at 1039.8,1183.5,1484.9,1643.6
There are also broadband noise bumps under these spikes.

planetary radar (track an asteroid) kinect exhibit

0-1000 .. rfi below 300 MHz.. Maybe from projector
1000-2000: lots of rfi. Might be sweeping across the band.

RadioSky, DeepSkyDetective:

the displays have combs around 73-74 MHz.
In lband the strongest birdies are around 1480-1485

ToDo:

Need to repeat experiment using the receivers on the telescope.

VC rfi using spectrum analyzer (2016)

Intro:

Setup:

Table of measurements done:

Plots of the data

Summary:

ToDo: