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+== Using Altus Metrum Products
+
+ === Being Legal
+
+ First off, in the US, you need an
+ link:http://www.altusmetrum.org/Radio/[amateur radio license]
+ or other authorization to legally operate the radio
+ transmitters that are part of our products.
+
+
+ === In the Rocket
+
+ In the rocket itself, you just need a flight computer
+ and a single-cell, 3.7 volt nominal Li-Po rechargeable
+ battery. An 850mAh battery weighs less than a 9V
+ alkaline battery, and will run a TeleMetrum, TeleMega
+ or EasyMega for hours. A 110mAh battery weighs less
+ than a triple A battery and is a good choice for use
+ with TeleMini or EasyMini.
+
+ By default, we ship TeleMini, TeleMetrum and TeleMega
+ flight computers 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 prefer to install an SMA connector so that you
+ can run a coaxial cable to an antenna mounted
+ elsewhere in the rocket. However, note that the GPS
+ antenna is fixed on all current products, so you
+ really want to install the flight computer in a bay
+ made of RF-transparent materials if at all possible.
+
+ === On the Ground
+
+ To receive the data stream from the rocket, you need
+ an antenna and short feed-line connected to one of our
+ link:http://www.altusmetrum.org/TeleDongle/[TeleDongle]
+ units. If possible, use an SMA to BNC adapter instead
+ of feedline between the antenna feedpoint and
+ TeleDongle, as this will give you the best
+ performance. 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.
+
+ 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.
+
+ Alternatively, a TeleBT attached with an SMA to BNC
+ adapter at the feed point of a hand-held yagi used in
+ conjunction with an Android device running AltosDroid
+ makes an outstanding ground station.
+
+ 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.
+
+ If your 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. AltosDroid on an
+ Android device with GPS receiver works great for this,
+ too!
+
+ 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 currently uses a Yaesu
+ FT1D, Bdale has a Yaesu VX-7R, which is a nicer radio
+ in most ways but doesn't support APRS.
+
+ So, to recap, on the ground the hardware you'll need includes:
+
+ . an antenna and feed-line or adapter
+ . a TeleDongle
+ . a notebook computer
+ . optionally, a hand-held GPS receiver
+ . optionally, an HT or receiver covering 435 MHz
+
+ The best hand-held commercial directional antennas we've found for radio
+ direction finding rockets are from
+ link:http://www.arrowantennas.com/[Arrow Antennas].
+
+ 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. TeleDongle and an SMA to BNC
+ adapter fit perfectly between the driven element and
+ reflector of Arrow antennas.
+
+ === Data Analysis
+
+ 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!
+
+ 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.
+
+ === Future Plans
+
+ We have designed and prototyped several “companion
+ boards” that can attach to the companion connector on
+ TeleMetrum, TeleMega and EasyMega flight computers to
+ collect more data, provide more pyro channels, and so
+ forth. We do not yet know if or when any of these
+ boards will be produced in enough quantity to sell.
+ If you have specific interests for data collection or
+ control of events in your rockets beyond the
+ capabilities of our existing productions, please let
+ us know!
+
+ 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...
+
+ Watch our link:http://altusmetrum.org/[web site] for
+ more news and information as our family of products
+ evolves!
projects / fw / altos / blobdiff