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Angelfire
carries a special GPS
telemetry system in the nosecone that makes it possible to capture the
entire flight trajectory. This trajectory data can then be loaded
into the Google
Earth program so that it is possible to view the launch site and see a
three dimensional representation of the flight trajectory. The
trajectory can be viewed from any angle by using the standard Google Earth
pan, tilt and zoom controls. This provides a nice "birds eye" view
of the flight that often times revels interesting things that were not
seen from the ground.
The telemetry system in the nosecone consists
of a
high speed
Garmin
GPS unit that transmits GPS fixes to the ground at the rate of five
readings per second using a
MaxStream 9XTend 1W spread spectrum frequency hopping 902-928 MHz
radio link. The data is received on the ground and saved into a small handheld
HP hx2415 iPAQ
Pocket PC running the
VisualGPS software. Many more details about this GPS telemetry system
are available here.
The photos below show the GPS telemetry system
that mounts inside the Angelfire nosecone. Click on either photo to get a
closer look. |
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Close up of the electronics package. |
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Note:
You can view the flight trajectories presented below by downloading the data file at the link
provided and
opening the data file with the Google
Earth program. If you already have Google
Earth installed, then you should be able to simply click on the data file link and
it will activate the Google Earth program and "fly you" to the
launch site and display the trajectory. If that doesn't work, then right click on the link, save
the file to a convenient place and then open the file from within Google
Earth. Google Earth is a FREE program
available here.
Have fun!
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Angelfire Flight # 18
Tripoli Idaho Launch
Oct. 18, 2008
Swan Falls, Idaho
Aerotech M1419 motor
Peak GPS altitude: 10,074 feet |
Link to photos of this flight
Listen to Kate's
audio report for this flight
This GPS trajectory has
been
color coded for each phase of the flight.
Red is motor burn, blue is coast phase, yellow is drogue chute deployed
and green is main chute deployed.
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Angelfire Flight # 16
Desert Heat Launch
July 19, 2008
Brothers Oregon
Aerotech M1419 motor
Peak GPS altitude: 10,271 feet |
Link to photos of this flight
This GPS trajectory has
been
color coded for each phase of the flight based on the ARTS altimeter data.
Red is motor burn, blue is coast phase, yellow is drogue chute deployed
and green is main chute deployed.
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Altitude reported by GPS
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Velocity reported by GPS
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Click on the charts above
to see the altitude and velocity data reported by the GPS. Each
point in the plot represents one GPS reading. The GPS updates at
five times per second, therefore, the readings are spaced apart by 200ms. The
peak altitude reported by the GPS was 10,271 feet above the ground.
The peak velocity was 528 mph. The descent velocity on the drogue
chute was about 65-70 mph. The descent velocity on the main chute was
about 15-17 mph.
There were two
MissileWorks barometric altimeters onboard.
One reported 10,402 feet and the other reported 10,669 feet. The
average of the two is 10,536 feet. The GPS reported 10,271 feet.
This amounts to a 2.6% difference in altitude as determined by the barometric
altimeters versus the GPS system. That amount of error seems pretty
typical based on my experience.
Click here to see these plots in PDF format
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Angelfire Flight # 15
Summer Skies Launch
June 22, 2008
Brothers Oregon
AMW M2200 Skidmark motor
Peak GPS altitude: 7,722 feet |
Link to photos of this flight
This GPS trajectory has
been
color coded for each phase of the flight based on the ARTS altimeter data.
Red is motor burn, blue is coast phase, yellow is drogue chute deployed
and green is main chute deployed.
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Altitude reported by GPS
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Velocity reported by GPS
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Click on the charts above
to see the altitude and velocity data reported by the GPS. Each
point in the plot represents one GPS reading. The GPS updates at
five times per second, therefore, the readings are spaced apart by 200ms. The
peak altitude reported by the GPS was 7,722 feet above the ground.
The peak velocity was 506 mph. The descent velocity on the drogue
chute was about 70 mph. The descent velocity on the main chute was
about 17 mph.
There were two
MissileWorks barometric altimeters onboard.
One reported 8,027 feet and the other reported 8,267 feet. The
average of the two is 8,147 feet. The GPS reported 7,722 feet.
This amounts to a 5.5% difference in altitude as determined by the barometric
altimeters and the GPS system. That's within the expected tolerance
range but a little more error than I typically see.
The GPS system stayed
locked onto its satellites during almost the entire flight. However, there
is a short 3 second dropout in the altitude data at about 125 seconds.
I assume this is due to the GPS antenna in the nosecone pointing off in a
direction of poor reception while hanging on the main chute.
Click
here to see the altitude plot in PDF format
Click
here to see the velocity plot in PDF format
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Angelfire Flight # 14
Tripoli Idaho Launch
Oct. 27, 2007
Swan Falls, Idaho
Aerotech M2500GG motor
Peak GPS altitude: 10,432 feet |
See photos of this flight.
This GPS trajectory has
been
color coded for each phase of the flight based on the ARTS altimeter data.
Red is motor burn, blue is coast phase, yellow is drogue chute deployed
and green is main chute deployed.
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Angelfire Flight # 13
Tripoli Idaho Launch
Oct. 27, 2007
Swan Falls, Idaho
Aerotech M1939 motor
Peak GPS altitude: 14,668 feet |
See photos of this flight.
View
altimeter data from this flight.
This GPS trajectory has
been
color coded for each phase of the flight based on the ARTS altimeter data.
Red is motor burn, blue is coast phase, yellow is drogue chute deployed
and green is main chute deployed.
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This view is looking
north. |
This view is looking
southwest. |
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Altitude reported by GPS
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Velocity reported by GPS
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The charts above
show the altitude and velocity data reported by the GPS system. Each
point in the plot represents one GPS reading. This GPS unit updates at
five times per second. (Readings are spaced apart by 200ms.) The
peak altitude was 14,668 feet above the ground. The peak velocity
reported by the GPS was 701 mph. (The peak velocity reported by the ARTS
recording altimeter was 661 mph.) The descent rate on the drogue chute
started out at about 72mph and gradually decreased to about 60 mph as the
air density increased at lower altitudes. The descent rate on the
main chute was about 15-16 mph. Click on either plot for a closer look.
These plots are also available in a
higher resolution PDF format that includes not only the "up" velocity
shown here but also the north and the east velocity vectors.
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Angelfire
Flight # 12
XPRS Launch
Sept. 15, 2007
Black Rock Desert, NV
Aerotech M1939 motor
Apogee: 15,214 feet
See photos of this flight
View altimeter data from
this flight
This GPS trajectory has
been
color coded for each phase of the flight by using timing information from the
on-board ARTS recording altimeter.
This view is looking to the
north east and from an elevation of about 14,000 feet above the playa at
the Black Rock dry lake bed. Each tic mark on the white vertical scale is
1000 feet. |
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Altitude reported by GPS
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Velocity reported by GPS
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The charts above show the
altitude and velocity data reported by the GPS system. Each point in
the plot represents one GPS reading. The
peak altitude was 15,214 feet above the ground. The peak velocity
reported by the GPS was 723 mph. (The peak velocity reported by the ARTS
recording altimeter was 676 mph.) The descent rate on the drogue chute
started out at about 75mph and gradually decreased to about 62 mph as the
air density increased at lower altitudes. The descent rate on the
main chute was about 17 mph. Click on either plot for a closer look.
These plots are also available in a
higher resolution PDF format that includes not only the "up" velocity
shown here but also the north and the east velocity vectors.
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Angelfire Flight # 11
LDRS Launch
July 13, 2007
Jean Dry Lake, NV
Aerotech M1419 motor |
Peak altitude: 10,326 feet.
View
altimeter data from this flight.
A view looking west is shown below. The flight trajectory is shown in
yellow. The launch pad was pretty much right in the middle of Jean Dry
Lake. Angelfire landed about 0.5 miles to the north of the lake bed.
See photos of this flight. |
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Altitude reported by GPS
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Velocity reported by GPS
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The charts above show the
altitude and velocity data reported by the GPS system. The
peak altitude was 10,326 feet above the ground. The peak velocity
was 535 mph. The descent rate on drogue chute was about 67 mph and
then 16 mph on the main chute.
The velocity data plotted
above is just the "up" component of velocity. The GPS also reports
the "north" and the "east" components of velocity to give a true 3D
velocity vector. To see plots of all the GPS data in PDF
format
click here.
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Angelfire Flight # 10
Oregon Rocketry Summer Skies Launch
June 16, 2007
Brothers Oregon launch site
Aerotech M1419 motor
See photos of this
launch |
Peak Altitude: 10,328 feet.
The GPS data from this flight was color coded
based on information from the onboard ARTS recording altimeter. The
section for motor burn is shown in red. The coast phase is in blue.
The yellow trace shows the path Angelfire fell while on drogue. The
green trace is the path while on main chute. |
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The white vertical scales in
these images have tic marks every 1000 feet. They help show the
10,328 foot apogee. The scale also drops
straight down to the ground from apogee so it shows the point on the
ground where apogee occurred. Click on the images below to get a better
look at them. |
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Looking West
Motor Burn
Coast Phase
Drogue chute
deployed
Main chute
deployed |
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Looking North
Motor Burn
Coast Phase
Drogue chute
deployed
Main chute
deployed |
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Looking East
Motor Burn
Coast Phase
Drogue chute
deployed
Main chute
deployed |
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Looking South
Motor Burn
Coast Phase
Drogue chute
deployed
Main chute
deployed |
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Altitude reported by GPS
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Velocity reported by GPS
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The charts above
show the altitude and velocity data reported by the GPS system. The
peak altitude was 10,328 feet above the ground. The peak velocity
reported by the GPS was 537 mph. (The peak velocity reported by the ARTS
recording altimeter was 515 mph.) The sink rate on the drogue chute
was 66 mph. The sink rate on the
main chute was about 13 mph. These plots are also available in a
higher resolution PDF format that includes not only the "up" velocity
shown here but also the north and the east velocity vectors.
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Angelfire
Flight # 9
Oct. 28, 2006
Tripoli Idaho
Swan Falls launch site
Aerotech M1419 motor
Apogee: 10,539 feet
See photos of this flight
This view is looking due
south. Angelfire landed 0.68 miles from the pad. The launch site is
situated about two miles from the Snake River canyon.
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The Big Picture!
This view is also looking
due south but it shows the yellow flight trajectory from a vantage point
that also includes Boise Idaho and some of the surrounding communities.
You can see where the launch site is with respect to everything else in
the area.
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Angelfire
Flight # 7
Aug. 19, 2006
Tripoli Idaho
Fairfield launch site
Aerotech L952 motor
Apogee: 5,141 feet
See photos of this flight
This view is looking WNW.
Angelfire left the launch
rail at a bit of an angle heading west. It landed 0.6 miles from the pad.
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Angelfire Flight # 6
Oregon Rocketry
Summer Skies Launch
June 18, 2006
Brothers Oregon launch site
Aerotech L952 motor
See photos of this
launch |
Apogee: 5,337 feet.
View altimeter data from this
flight
The first image below is a
view looking north east from south west of the launch site. The
Angelfire trajectory is shown in yellow and the small town of Brothers is
labeled off in the distance. Angelfire left the launch rail at an
angle heading north. The main chute was also deployed just past
apogee. The second image below is looking east south east. |
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Altitude reported by GPS
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Velocity reported by GPS
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Click on the charts above
to see the altitude and velocity data reported by the GPS. Each
point in the plot represents one GPS reading. The
peak altitude was 5,337 feet above the ground.
The peak velocity was 350 mph. The descent velocity on the main
chute was 17mph but then dropped to about 12 mph at lower altitude.
Remember the launch site is already 4500 feet above sea level.
The GPS system stayed
locked onto the satellites during the whole flight. However, there
is a short 3 second dropout in the data at 145 seconds where I was
fiddling with the hand held computer and not pointing the receiver antenna at the
rocket! Data flow resumed immediately as soon as I returned to
pointing the antenna properly.
The velocity data plotted
above is just the "up" component of velocity. The GPS also reports
the "north" and the "east" components of velocity to give a true 3D
velocity vector. This flight was not perfectly vertical and
the plots show that. The north velocity component peaked at 67 mph
and the east component peaked at -48 mph. (Angelfire went a little
to the north west.) To see plots of all of the GPS data in PDF
format
click here.
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Angelfire Flight # 5
FITS Launch
May 28, 2006
Mansfield Washington
Aerotech M1419 motor
Peak altitude: 10,021 feet
See
photos of this launch
See altimeter data from this
launch |
A view looking due north is
shown below. The trajectory is shown in yellow and the landing location is
shown by the yellow "X" on the ground. The GPS receiver captured
good data all the up and during most of the descent, but unfortunately, it
lost lock when Angelfire had descended to about 2000 feet above the
ground. This means the trajectory in this photo ends about
2000 feet above the ground. An "X" was added to the photo to show
where Angelfire eventually touched down. |
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Altitude reported by GPS
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Velocity reported by GPS
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Click on the charts above
to see the altitude and velocity data reported by the GPS. Each
point in the plot represents one GPS reading. The
peak altitude was 10,021 feet above the ground and the data stops at about
110 seconds into the flight when there was still 2000 feet to go.
The peak velocity was 542 mph. The descent velocity on drogue chute
was about 65 to 70 mph.
The velocity data plotted
above is just the "up" component of velocity. The GPS also reports
the "north" and the "east" components of velocity to give a true 3D
velocity vector.
Click here to view
these
GPS data plots in PDF format
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