Q: What is the advantage of the GPSFlight System
over similar systems?
Answer: GPSFlight's
transmitters are smaller, more capable, and less expensive
than other solutions. Our units are better than
Cellular devices because we don't have airtime charges and
our update rates are much faster. Our units are better
than RFID because our range is much better. Our units
are better than competing units because they are much
smaller.
Q:
Q: Why do I need the Digital Altimeter if I
already get GPS Altitude data from my unit?
Answer: The DAM provides
more accurate altitude information, especially under high
stress environments. Where GPS altitude can be accurate to
30 ft or so with perfect conditions, and is generally
accurate to 100ft or so, the DAM can be accurate to 1-3
feet. It also provides real-time temperature
information.
Q: Do you carry a 1-watt transmitter?
Is it compatible with the STXe?
Answer: Yes. Yes, we do offer
the 1-watt transmitter in 900mhz. It can be used with
the STXe, but you will need a new base station that operates
with the 1-watt transmitters. Contact
info@gpsflight.com for
pricing and delivery time.
Q: Do I need a HAM License?
Answer: No. The
radios are licensed by the FCC to be used without requirement
of the end user having a special license. However, modifying
the radio by increasing its power, etc will violate FCC
regulations and is prohibited.
Q:
Q: How
does this system compare to using a HAM Radio and GPS to send
data to another HAM radio?
Answer: For years, amateur radio users have 'homebrewed'
HT-telemetry devices' by hacking a small handheld, wiring in a
GPS to the speaker port, and creating a lightweight APRS
station. These are heavier, and have much less range than the
GPSFlight units because the radios are not tuned to send data,
and suffer from significant fade-in/out which trashes the
telemetry data. What's more, assembling the HT+GPS+TNC
components will cost much MORE than GPSFlight units, be
heavier, and require a license. In fact, the 'hacking' method
is lots of fun, but does not deliver true 'telemetry' like
GPSFlight.
See comparison here.
Q:
Q: How much do these units weigh?
Answer: The units are designed to be small and
lightweight.
-
The STXe
weighs about 60 Grams
-
The
STXe2 weighs 50 Grams without antenna
-
The XTPr weighs 50 Grams without
antenna
Q: Why is
Spread Spectrum able to send data so much farther than 'HAM'
radios with the same power?
Answer: The radios are built to send data, and they have very
sensitive receive capability. A GPSFlight radio can pick up
and deliver data out of a signal at weak as -110db and
sometimes higher. Compared to HT HAM radios, that may pick up
a data signal at -70db, you'd see and order of magnitude
greater range. In addition, due to the frequency hopping, the
radios can find stronger channels if interference becomes an
issue.
Q:
Q: What batteries do I need for the transmitters? How long do they last?
Answer: This depends on the unit used.
-
The STXe can be run on any power
supply that provides 4-5.5 volts DC. The connector is a
3 pin header. This means a 4 pack of AA or AAA
batteries can be used.
-
The STXe2 has a 1.3mm power jack
connector, and can be powered from any voltage source
from 5VDC to 12VDC.
-
The XTPr has a 1.3mm power jack
connector, and can be powered from any voltage source
from 5VDC to 12VDC, as well as being powered by the USB
port.
For the 1-watt transmitter, you will need
to provide for 800ma draw at 4.8-5.0v.
The
following table is a good guideline, but your results will
vary:
|
Battery |
100Mw Radio |
1000 Mw Radio |
|
Capacity(mah) |
|
|
|
320 |
1.04 hours |
Not recommended |
|
600 |
1.96 hours |
Not recommended |
|
700 |
2.28 hours |
Not recommended |
|
1200 |
3.92 hours |
1.2 hours |
|
2000 |
6.53 hours |
2.2 hours |
|
2500 |
8.16 hours |
2.8 hours |
|
3200 |
10.44 hours |
3.2 hours |
|
4000 |
13.06 hours |
4.3 hours |
|
Hours of Run-Time - Estimated |
|
Q:
Q: Is GPS accurate for Altitude? I heard it was more
accurate for horizontal position than vertical
Answer: True. GPS is much more accurate horizontally, +-
10Meters average vs. +- 50Meters vertically. This is largely
dependent upon the GPS satellite constellation as well. If
more accurate altitude is required, select the STXe2 or XTPr
transmitters.
Q:
Q:
Q: How can more than one GPSFlight Transmitter operate in
the same area?
Answer: Using any of our Transmitter units, you can have literally thousands
of transmitters in the same area, and plot them all on the
same screen with GPSTeam or GPSTeam Pro. In addition, GPSFlight
units provide 7
totally separate Network IDs, each of which can contain
thousands of units in the same area.
Q:
Q: What software can be used to capture and monitor the GPS
data?
Answer: Any standard NMEA applications will work when
running the GPSFlight Transmitters are sending data in NMEA mode. These include VirtualGPS, VirtualGPSXP, Delorme StreetAtlas, etc. Software is available for PC, Palm, Windows
CE, and even directly connected to other GPS devices.
Basically any software that can read and report on NEMA 183
sentences for position and speed will work for standard units.
However, for tracking using the GPSFlight TracID SWARM
protocol, you will need GPSFlight software. This
software is able to decode data from multiple units at the
same time, and also displays other sensor information not
found in NMEA.
Q:
Q: What parts do I need to send GPS Telemetry from a UAV or
remote vehicle?
Answer: You need a Transmitter module onboard the
vehicle you want to track, along with an antenna for the radio
(unless you are using an integrated antenna). You also need a 4.8v Battery
or power source.. On the ground you
will need a base station (RX-Base) which includes antenna,
power supply (USB if desired), and data cable. To view the TracID data
you will need to use GPS-Dashboard or GPS-Team
Q:
Q: You say 15-20 miles 'line of sight' what if I have trees
or buildings in between - what would my range be?
Answer: Line of sight means perfectly unobstructed. Straight
up is best. If you have buildings or trees your range will be
significantly reduced. 1500' through trees & buildings is
standard for the 100mw radio, 1 mile for the 1-watt
transmitter. We have customers who have used the system over
58
miles line of sight using the 100mw radio, so your mileage may vary!
Q:
:
Q: Doesn't 900 Mhz have a bad reputation for being a
'crowded' band?
Answer: Maybe in the past. If you try to use your unit near a garage
door opener tradeshow, you MIGHT have some trouble!
Seriously though, 900 MHz is in use by many devices, which is
why the spread spectrum frequency hopping is important. In
our tests, we've never seen any interference despite the fact
we have many 900 MHz cordless phones and 802.11 networks in
the neighborhood.
Q:
Q: What is the output power of the 900 MHz Radios?
Answer: The standard radios put out about 110 mw of RF
power, the LP radios put out about 10mw. The new 1-watt
radios are adjustable from 10 mw to 1000mw (1-watt).
Here are the answers to some
frequently asked questions: