ARBONET

“A poor man’s space program”

Primarily funded and spear-headed by:Primarily funded and spear-headed by:Doug Loughmiller – W5BLDoug Loughmiller – W5BLMichael Willett – K5NOTMichael Willett – K5NOT

With support from several enthusiastic individuals With support from several enthusiastic individuals and clubs and clubs

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Local Local Clubs Involved with ARBONET:Clubs Involved with ARBONET:

• North Texas Balloon Project (mentors / chasers)North Texas Balloon Project (mentors / chasers)• Red River Valley Amateur Radio Club (NE TX)Red River Valley Amateur Radio Club (NE TX)• Fannin County Amateur Radio Club (NE TX)Fannin County Amateur Radio Club (NE TX)• Lockheed Amateur Radio Club – Ft. WorthLockheed Amateur Radio Club – Ft. Worth• Richardson Wireless Klub (guest payloads)Richardson Wireless Klub (guest payloads)• Irving Amateur Radio ClubIrving Amateur Radio Club

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Adventures:

GPSL-2009

Aka: Which way did it go?

GPSL 2009Arrived with payloads ready and willing to go flying, but…. Became “enlightened” by Bill Brown… “ The Copernicus GPS has issues and settings you need to address…”

We did not drive all the way up here to sit on the sidelines…. So we flew anyway!

We thought we would at least have Lat / Long… And…. After the radio batteries were depleted…..

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Our payload was found a week later in grazing land by ranchers in Redland, KS.

After reward money and postage, the payload came back to Texas!

During the recovery, Doug and I never laughed so hard, making fun of the female voice beacon who talked a lot and yet said so little!

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0100020003000400050006000700080009000

100001

4

35

55

85

11

5

13

5

16

5

19

5

Alitutude (m)

Temperature

Pressure

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29,616 ftLast Valid GPSData Point

Max altitude obtained estimated by Bill Brown WB8ELK as about 110,000 feet

ARBONETGPSL 2009 Flight

Configuration

Balloon

Manifold Pressure Sensor Feed

ElectronicsValve (closed for this flight)

Parachute(Intended to be closed for flight)

6 Minute Video

ARBONET flight at GPSL 2009

Interesting Data:

Envelope Pressure

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• If P is nearly static, F /A are not changing or equal in change• If P increases, F is increasing or A is decreasing• If P decreases, F is decreasing or A is increasing

P = F/A

Where P = PressureWhere F = ForceWhere A = Area

ARBONETGPSL 2009 Flight

Configuration

Balloon

Manifold Pressure Sensor Feed

ElectronicsValve (closed for this flight)

Parachute(Intended to be closed for flight)

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Pressure Sensors:

Measured Pressure = Ambient Pressure

More Pressure

Diaphragm Diaphragm

Ambient Air Ambient Air

Diaphragm Diaphragm

Ambient Air Ambient Air

Balloon Balloon

ARBONETP=F/A

Rs

-10

0

10

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70

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90

14 15 25 35 45 50 55 65 75 85 95 105

115

120

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135

145

155

165

175

185

195

197

Burst

Pressure

TemperaturePressure

Internal TemperatureOf Payload

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• We tend to think balloons behave in a linear fashion since the ascent is nearly linear. Thus a balloon that is getting bigger should have equal or more pressure…

• We found the behavior is not linear, but a balance of P=F/A that was not expected

• Other factors also contribute – He impurities, point of measurement, etc.

• The Latex stretching is not linear, and the “mechanical maximum” (ability to contain the gas within) has a limit that is recognizable just before burst!

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-5

0

5

10

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40

45

50

ARBONET Envelope Pressure relative to ambient

(not calibrated )

This area may actually become a vacuum per similar results from U of MN students

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-5

0

5

10

15

20

25

30

35

40

45

50

Envelope Pressure relative to ambient

(not calibrated )

To modulate the optimum envelope pressure, we need to detect and remain in this region

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Possible Flight Profile

Phase 1Launch

Phase 4Ascent

Phase 2Ascent

Phase 6Deflation and Return via Balloon

Phase 7Recovery

TIME

ALT

ITU

DE

RDF Tone

80K-100K ft Phase 3Sense return ofPositive pressure Trend and ModulatePressure

Phase 6 Return to Hover(Dump Ballast)

Phase 5Hover

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How envelope modulation may be used:How envelope modulation may be used:

• Hang a balloon for longer-term, high-altitude Hang a balloon for longer-term, high-altitude experiments, re-call it when desiredexperiments, re-call it when desired

• A repeater in the sky for long periods of timeA repeater in the sky for long periods of time• Controlled descents and with ballast, possible Controlled descents and with ballast, possible

controlled landings by chase teamcontrolled landings by chase team• Gain higher altitudes, even though the ft/min is Gain higher altitudes, even though the ft/min is

constantly decreasing after maximum expansion, you constantly decreasing after maximum expansion, you are still climbing for many minutes!are still climbing for many minutes!

Note: Likely venting issue if in the zero pressure region!Note: Likely venting issue if in the zero pressure region!

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Project 1:Project 1:

New Voice Beacon New Voice Beacon PayloadPayload

The new voice beacon payload:The new voice beacon payload:

• Same lost blonde-sounding women’s voice we all love.Same lost blonde-sounding women’s voice we all love.• Inventek GPS with Sarantel antennaInventek GPS with Sarantel antenna• 0.3 PSI rated pressure sensor (higher precision)0.3 PSI rated pressure sensor (higher precision)• Embedded repeater via 70cm and 2m radiosEmbedded repeater via 70cm and 2m radios• Built in USB for log retrieval and troubleshooting Built in USB for log retrieval and troubleshooting • DS1822 Digital thermometer Internal and ExternalDS1822 Digital thermometer Internal and External• Sensiron Thermometer and humidity measurement device Sensiron Thermometer and humidity measurement device • 2Mb to 4Mb logging memory capacity2Mb to 4Mb logging memory capacity• Separate, controllable power busses for almost all Separate, controllable power busses for almost all

electronics to reduce power consumptionelectronics to reduce power consumption• All on a 3.8 x 2.5 double-sided boardAll on a 3.8 x 2.5 double-sided board

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ARBONET VOICE BEACON Design Team :ARBONET VOICE BEACON Design Team :

• Patrick Whitfill, Firmware Guru / Operational Patrick Whitfill, Firmware Guru / Operational AspectsAspects

• Michael Willett, K5NOT, Systems design, Michael Willett, K5NOT, Systems design, Hardware design and JOATHardware design and JOAT

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ARBONETThe new voice beacon main board:The new voice beacon main board:

ARBONETThe new voice beacon main board:The new voice beacon main board:

Pgm HdrUSB Hdr

Pressure Sensor

Voice Synthesizer(Backside)

Analog In and Servos

70cmAntenna

GPS

Open Tracker SMT2mAntenna

Power In

CPU andmemory

70 cm radio(backside)

2m radio(backside)

USB Chip(backside)

Each section uses Power Control

ARBONETThe new voice beacon main board:The new voice beacon main board:

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Project 2:Project 2:

Slow Scan TV ModuleSlow Scan TV Module

Doug Loughmiller, W5BL – ARBONET

GPSL 2010 Hutchinson, KS

July 23rd, 2010

A look at the OE1RIB Embedded Mobile SSTV for use in High Altitude

Balloon Flights

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Design Credit• The concept, design and implementation of the Mobile

Embedded SSTV System is 100% the result of the efforts of Richard Prinz, OE1RIB who has graciously made his design materials available to W5BL for use on upcoming ARBONET flights.

• Doug’s efforts have simply been to identify Richard’s work and to promote his design as a viable solution for a low power, low cost, portable SSTV solution suitable for use as a payload on High Altitude Balloon Flights..

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Image Options for High Altitude Balloon Flights

• ATV– Platform Stabilization, limited ground stations

• Digital Photography / Digital Video– Excellent Images, but can only be viewed post flight

• SSTV– Excellent Image quality, downlink in near real-time,

easy ground station solution with receiver, lap-top and shareware

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ARBONET SSTV ActivityARBONET

What We Really Want To See!

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Commercial, Portable Off-the-Shelf SSTV Options

are Limited

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A Novel Home-Brew Solution

• Original Article

Appeared in “Funkamateur” 8/2007• OE1RIB Web Site:

http://www.min.at/prinz/oe1rib/SSTV/#Purpose

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Features of The Universal Mobile Embedded SSTV System

• Supports Black and White or Color Images Using Martin 1 with either 320 x 240 or 320 x 256 pixels

• Supports SSTV VIS code, Optional CW station ID• Multiple transmissions of a captured image or

single transmission of multiple images• Battery backed Real-time clock for time and date

display on image or via CW

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• Built-in temperature sensor in image display or via CW

• In-circuit Programmable • User defined Font Editor For Status Text

Messages• Configurable via RS-232 Port using HyperTerm-

like serial programs• Small Form Factor• Light Weight

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System Image Using Martin1

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Circuit Details

• Microprocessor = Microchip PIC18F458• Video Buffer= AverLogic AL422B• Real Time Clock= Maxim DS1307• Temperature Sensor= Microchip TC74• Camera= Sander/ ETC CAM-C3188A• Low Power System operates at 100 mA during

image capture and transmission , 90 mA at idle.

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Construction

• Almost all parts are readily available through catalog distributors (Mouser, Digi-key etc.)–Exceptions: Averlogic Frame Buffer, Maxim

MAX1818 and Sanders Camera• Boards can be obtained through ExpressPCB• Software downloadable from the Web site• Some surface mount components

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Conclusion

• Ideal Solution for BalloonSat Operations• Thanks to Richard, OE1RIB for Sharing his

design• Stay Tuned for Images from Upcoming

ARBONET flights.• www.arbonet.net

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