+ <section>
+ <title>Manage Frequencies</title>
+ <para>
+ This brings up a dialog where you can configure the set of
+ frequencies shown in the various frequency menus. You can
+ add as many as you like, or even reconfigure the default
+ set. Changing this list does not affect the frequency
+ settings of any devices, it only changes the set of
+ frequencies shown in the menus.
+ </para>
+ </section>
+ </section>
+ <section>
+ <title>Flash Image</title>
+ <para>
+ This reprograms any Altus Metrum device by using a TeleMetrum
+ or TeleDongle as a programming dongle. Please read the
+ directions for flashing devices in the Updating Device
+ Firmware chapter below.
+ </para>
+ <para>
+ Once you have the programmer and target devices connected,
+ push the 'Flash Image' button. That will present a dialog box
+ listing all of the connected devices. Carefully select the
+ programmer device, not the device to be programmed.
+ </para>
+ <para>
+ Next, select the image to flash to the device. These are named
+ with the product name and firmware version. The file selector
+ will start in the directory containing the firmware included
+ with the AltosUI package. Navigate to the directory containing
+ the desired firmware if it isn't there.
+ </para>
+ <para>
+ Next, a small dialog containing the device serial number and
+ RF calibration values should appear. If these values are
+ incorrect (possibly due to a corrupted image in the device),
+ enter the correct values here.
+ </para>
+ <para>
+ Finally, a dialog containing a progress bar will follow the
+ programming process.
+ </para>
+ <para>
+ When programming is complete, the target device will
+ reboot. Note that if the target device is connected via USB, you
+ will have to unplug it and then plug it back in for the USB
+ connection to reset so that you can communicate with the device
+ again.
+ </para>
+ </section>
+ <section>
+ <title>Fire Igniter</title>
+ <para>
+ This activates the igniter circuits in TeleMetrum to help test
+ recovery systems deployment. Because this command can operate
+ over the Packet Command Link, you can prepare the rocket as
+ for flight and then test the recovery system without needing
+ to snake wires inside the air-frame.
+ </para>
+ <para>
+ Selecting the 'Fire Igniter' button brings up the usual device
+ selection dialog. Pick the desired TeleDongle or TeleMetrum
+ device. This brings up another window which shows the current
+ continuity test status for both apogee and main charges.
+ </para>
+ <para>
+ Next, select the desired igniter to fire. This will enable the
+ 'Arm' button.
+ </para>
+ <para>
+ Select the 'Arm' button. This enables the 'Fire' button. The
+ word 'Arm' is replaced by a countdown timer indicating that
+ you have 10 seconds to press the 'Fire' button or the system
+ will deactivate, at which point you start over again at
+ selecting the desired igniter.
+ </para>
+ </section>
+ <section>
+ <title>Scan Channels</title>
+ <para>
+ This listens for telemetry packets on all of the configured
+ frequencies, displaying information about each device it
+ receives a packet from. You can select which of the three
+ telemetry formats should be tried; by default, it only listens
+ for the standard telemetry packets used in v1.0 and later
+ firmware.
+ </para>
+ </section>
+ <section>
+ <title>Load Maps</title>
+ <para>
+ Before heading out to a new launch site, you can use this to
+ load satellite images in case you don't have internet
+ connectivity at the site. This loads a fairly large area
+ around the launch site, which should cover any flight you're likely to make.
+ </para>
+ <para>
+ There's a drop-down menu of launch sites we know about; if
+ your favorites aren't there, please let us know the lat/lon
+ and name of the site. The contents of this list are actually
+ downloaded at run-time, so as new sites are sent in, they'll
+ get automatically added to this list.
+ </para>
+ <para>
+ If the launch site isn't in the list, you can manually enter the lat/lon values
+ </para>
+ <para>
+ Clicking the 'Load Map' button will fetch images from Google
+ Maps; note that Google limits how many images you can fetch at
+ once, so if you load more than one launch site, you may get
+ some gray areas in the map which indicate that Google is tired
+ of sending data to you. Try again later.
+ </para>
+ </section>
+ <section>
+ <title>Monitor Idle</title>
+ <para>
+ This brings up a dialog similar to the Monitor Flight UI,
+ except it works with the altimeter in "idle" mode by sending
+ query commands to discover the current state rather than
+ listening for telemetry packets.
+ </para>
+ </section>
+ </chapter>
+ <chapter>
+ <title>Using Altus Metrum Products</title>
+ <section>
+ <title>Being Legal</title>
+ <para>
+ First off, in the US, you need an <ulink url="http://www.altusmetrum.org/Radio/">amateur radio license</ulink> or
+ other authorization to legally operate the radio transmitters that are part
+ of our products.
+ </para>
+ </section>
+ <section>
+ <title>In the Rocket</title>
+ <para>
+ In the rocket itself, you just need a <ulink url="http://www.altusmetrum.org/TeleMetrum/">TeleMetrum</ulink> or
+ <ulink url="http://www.altusmetrum.org/TeleMini/">TeleMini</ulink> board and
+ a Li-Po rechargeable battery. An 860mAh battery weighs less than a 9V
+ alkaline battery, and will run a TeleMetrum for hours.
+ A 110mAh battery weighs less than a triple A battery and will run a TeleMetrum for
+ a few hours, or a TeleMini for much (much) longer.
+ </para>
+ <para>
+ By default, we ship the altimeters with a simple wire antenna. If your
+ electronics bay or the air-frame it resides within is made of carbon fiber,
+ which is opaque to RF signals, you may choose to have an SMA connector
+ installed so that you can run a coaxial cable to an antenna mounted
+ elsewhere in the rocket.
+ </para>
+ </section>
+ <section>
+ <title>On the Ground</title>
+ <para>
+ To receive the data stream from the rocket, you need an antenna and short
+ feed-line connected to one of our <ulink url="http://www.altusmetrum.org/TeleDongle/">TeleDongle</ulink> units. The
+ TeleDongle in turn plugs directly into the USB port on a notebook
+ computer. Because TeleDongle looks like a simple serial port, your computer
+ does not require special device drivers... just plug it in.
+ </para>
+ <para>
+ The GUI tool, AltosUI, is written in Java and runs across
+ Linux, Mac OS and Windows. There's also a suite of C tools
+ for Linux which can perform most of the same tasks.
+ </para>
+ <para>
+ After the flight, you can use the radio link to extract the more detailed data
+ logged in either TeleMetrum or TeleMini devices, or you can use a mini USB cable to plug into the
+ TeleMetrum board directly. Pulling out the data without having to open up
+ the rocket is pretty cool! A USB cable is also how you charge the Li-Po
+ battery, so you'll want one of those anyway... the same cable used by lots
+ of digital cameras and other modern electronic stuff will work fine.
+ </para>
+ <para>
+ If your TeleMetrum-equipped rocket lands out of sight, you may enjoy having a hand-held GPS
+ receiver, so that you can put in a way-point for the last reported rocket
+ position before touch-down. This makes looking for your rocket a lot like
+ Geo-Caching... just go to the way-point and look around starting from there.
+ </para>
+ <para>
+ You may also enjoy having a ham radio "HT" that covers the 70cm band... you
+ can use that with your antenna to direction-find the rocket on the ground
+ the same way you can use a Walston or Beeline tracker. This can be handy
+ if the rocket is hiding in sage brush or a tree, or if the last GPS position
+ doesn't get you close enough because the rocket dropped into a canyon, or
+ the wind is blowing it across a dry lake bed, or something like that... Keith
+ and Bdale both currently own and use the Yaesu VX-7R at launches.
+ </para>
+ <para>
+ So, to recap, on the ground the hardware you'll need includes:
+ <orderedlist inheritnum='inherit' numeration='arabic'>
+ <listitem>
+ an antenna and feed-line
+ </listitem>
+ <listitem>
+ a TeleDongle
+ </listitem>
+ <listitem>
+ a notebook computer
+ </listitem>
+ <listitem>
+ optionally, a hand-held GPS receiver
+ </listitem>
+ <listitem>
+ optionally, an HT or receiver covering 435 MHz
+ </listitem>
+ </orderedlist>
+ </para>
+ <para>
+ The best hand-held commercial directional antennas we've found for radio
+ direction finding rockets are from
+ <ulink url="http://www.arrowantennas.com/" >
+ Arrow Antennas.
+ </ulink>
+ The 440-3 and 440-5 are both good choices for finding a
+ TeleMetrum- or TeleMini- equipped rocket when used with a suitable 70cm HT.
+ </para>
+ </section>
+ <section>
+ <title>Data Analysis</title>
+ <para>
+ Our software makes it easy to log the data from each flight, both the
+ telemetry received during the flight itself, and the more
+ complete data log recorded in the flash memory on the altimeter
+ board. Once this data is on your computer, our post-flight tools make it
+ easy to quickly get to the numbers everyone wants, like apogee altitude,
+ max acceleration, and max velocity. You can also generate and view a
+ standard set of plots showing the altitude, acceleration, and
+ velocity of the rocket during flight. And you can even export a TeleMetrum data file
+ usable with Google Maps and Google Earth for visualizing the flight path
+ in two or three dimensions!
+ </para>
+ <para>
+ Our ultimate goal is to emit a set of files for each flight that can be
+ published as a web page per flight, or just viewed on your local disk with
+ a web browser.
+ </para>
+ </section>
+ <section>
+ <title>Future Plans</title>
+ <para>
+ In the future, we intend to offer "companion boards" for the rocket that will
+ plug in to TeleMetrum to collect additional data, provide more pyro channels,
+ and so forth. A reference design for a companion board will be documented
+ soon, and will be compatible with open source Arduino programming tools.
+ </para>
+ <para>
+ We are also working on the design of a hand-held ground terminal that will
+ allow monitoring the rocket's status, collecting data during flight, and
+ logging data after flight without the need for a notebook computer on the
+ flight line. Particularly since it is so difficult to read most notebook
+ screens in direct sunlight, we think this will be a great thing to have.
+ </para>
+ <para>
+ Because all of our work is open, both the hardware designs and the software,
+ if you have some great idea for an addition to the current Altus Metrum family,
+ feel free to dive in and help! Or let us know what you'd like to see that
+ we aren't already working on, and maybe we'll get excited about it too...
+ </para>
+ </section>
+ </chapter>
+ <chapter>
+ <title>Altimeter Installation Recommendations</title>
+ <para>
+ Building high-power rockets that fly safely is hard enough. Mix
+ in some sophisticated electronics and a bunch of radio energy
+ and oftentimes you find few perfect solutions. This chapter
+ contains some suggestions about how to install Altus Metrum
+ products into the rocket air-frame, including how to safely and
+ reliably mix a variety of electronics into the same air-frame.
+ </para>
+ <section>
+ <title>Mounting the Altimeter</title>
+ <para>
+ The first consideration is to ensure that the altimeter is
+ securely fastened to the air-frame. For TeleMetrum, we use
+ nylon standoffs and nylon screws; they're good to at least 50G
+ and cannot cause any electrical issues on the board. For
+ TeleMini, we usually cut small pieces of 1/16" balsa to fit
+ under the screw holes, and then take 2x56 nylon screws and
+ screw them through the TeleMini mounting holes, through the
+ balsa and into the underlying material.
+ </para>
+ <orderedlist inheritnum='inherit' numeration='arabic'>
+ <listitem>
+ Make sure TeleMetrum is aligned precisely along the axis of
+ acceleration so that the accelerometer can accurately
+ capture data during the flight.
+ </listitem>
+ <listitem>
+ Watch for any metal touching components on the
+ board. Shorting out connections on the bottom of the board
+ can cause the altimeter to fail during flight.
+ </listitem>
+ </orderedlist>
+ </section>
+ <section>
+ <title>Dealing with the Antenna</title>
+ <para>
+ The antenna supplied is just a piece of solid, insulated,
+ wire. If it gets damaged or broken, it can be easily
+ replaced. It should be kept straight and not cut; bending or
+ cutting it will change the resonant frequency and/or
+ impedance, making it a less efficient radiator and thus
+ reducing the range of the telemetry signal.
+ </para>
+ <para>
+ Keeping metal away from the antenna will provide better range
+ and a more even radiation pattern. In most rockets, it's not
+ entirely possible to isolate the antenna from metal
+ components; there are often bolts, all-thread and wires from other
+ electronics to contend with. Just be aware that the more stuff
+ like this around the antenna, the lower the range.
+ </para>
+ <para>
+ Make sure the antenna is not inside a tube made or covered
+ with conducting material. Carbon fiber is the most common
+ culprit here -- CF is a good conductor and will effectively
+ shield the antenna, dramatically reducing signal strength and
+ range. Metallic flake paint is another effective shielding
+ material which is to be avoided around any antennas.
+ </para>
+ <para>
+ If the ebay is large enough, it can be convenient to simply
+ mount the altimeter at one end and stretch the antenna out
+ inside. Taping the antenna to the sled can keep it straight
+ under acceleration. If there are metal rods, keep the
+ antenna as far away as possible.
+ </para>
+ <para>
+ For a shorter ebay, it's quite practical to have the antenna
+ run through a bulkhead and into an adjacent bay. Drill a small
+ hole in the bulkhead, pass the antenna wire through it and
+ then seal it up with glue or clay. We've also used acrylic
+ tubing to create a cavity for the antenna wire. This works a
+ bit better in that the antenna is known to stay straight and
+ not get folded by recovery components in the bay. Angle the
+ tubing towards the side wall of the rocket and it ends up
+ consuming very little space.
+ </para>
+ <para>
+ If you need to place the antenna at a distance from the
+ altimeter, you can replace the antenna with an edge-mounted
+ SMA connector, and then run 50Ω coax from the board to the
+ antenna. Building a remote antenna is beyond the scope of this
+ manual.
+ </para>
+ </section>
+ <section>
+ <title>Preserving GPS Reception</title>
+ <para>
+ The GPS antenna and receiver in TeleMetrum are highly
+ sensitive and normally have no trouble tracking enough
+ satellites to provide accurate position information for
+ recovering the rocket. However, there are many ways to
+ attenuate the GPS signal.
+ <orderedlist inheritnum='inherit' numeration='arabic'>
+ <listitem>
+ Conductive tubing or coatings. Carbon fiber and metal
+ tubing, or metallic paint will all dramatically attenuate the
+ GPS signal. We've never heard of anyone successfully
+ receiving GPS from inside these materials.
+ </listitem>
+ <listitem>
+ Metal components near the GPS patch antenna. These will
+ de-tune the patch antenna, changing the resonant frequency
+ away from the L1 carrier and reduce the effectiveness of the
+ antenna. You can place as much stuff as you like beneath the
+ antenna as that's covered with a ground plane. But, keep
+ wires and metal out from above the patch antenna.
+ </listitem>
+ </orderedlist>
+ </para>
+ </section>
+ <section>
+ <title>Radio Frequency Interference</title>
+ <para>
+ Any altimeter will generate RFI; the digital circuits use
+ high-frequency clocks that spray radio interference across a
+ wide band. Altusmetrum altimeters generate intentional radio
+ signals as well, increasing the amount of RF energy around the board.
+ </para>
+ <para>
+ Rocketry altimeters also use precise sensors measuring air
+ pressure and acceleration. Tiny changes in voltage can cause
+ these sensor readings to vary by a huge amount. When the
+ sensors start mis-reporting data, the altimeter can either
+ fire the igniters at the wrong time, or not fire them at all.
+ </para>
+ <para>
+ Voltages are induced when radio frequency energy is
+ transmitted from one circuit to another. Here are things that
+ increase the induced voltage and current:
+ </para>
+ <itemizedlist>
+ <listitem>
+ Keep wires from different circuits apart. Moving circuits
+ further apart will reduce RFI.
+ </listitem>
+ <listitem>
+ Avoid parallel wires from different circuits. The longer two
+ wires run parallel to one another, the larger the amount of
+ transferred energy. Cross wires at right angles to reduce
+ RFI.
+ </listitem>
+ <listitem>
+ Twist wires from the same circuits. Two wires the same
+ distance from the transmitter will get the same amount of
+ induced energy which will then cancel out. Any time you have
+ a wire pair running together, twist the pair together to
+ even out distances and reduce RFI. For altimeters, this
+ includes battery leads, switch hookups and igniter
+ circuits.
+ </listitem>
+ <listitem>
+ Avoid resonant lengths. Know what frequencies are present
+ in the environment and avoid having wire lengths near a
+ natural resonant length. Altusmetrum products transmit on the
+ 70cm amateur band, so you should avoid lengths that are a
+ simple ratio of that length; essentially any multiple of 1/4
+ of the wavelength (17.5cm).
+ </listitem>
+ </itemizedlist>