HP ALTO-G12 User Manual
Alto-G12 GPS
Operating Instructions
Introduction
The units we have purchased are manufactured by Corvallis Microtechnology, Inc., a subsidiary
of Hewlett-Packard. The unit model is the “Alto-G12”. If the units are used with the
backpack, we can collect real-time differential data (no post processing). If the units are used
without the backpack, the data can be differentially post-processed later for sub-meter
accuracy (using the base station data at http://www.uwsp.edu/cnr/acl ), or can be used as is
with an accuracy of about 5m.
F1, F2, F3, F4, F5 function
keys. At the bottom of the
display, you are often
presented with a series of
commands. The position of
the command corresponds
to a function key. Press the
function key to use the
command.
The ESC key moves you back
one screen. If you keep
pressing it you will always
end up at the main options
screen.
ON button. If the unit is already on,
press is again from any other screen
to get to the Status report screen
(info on current location, satellites,
PDOP, battery charge status, etc).
Press the ESC button to leave this
ARROW keys. Use the up and down
arrows to move between
options/fields. Use the left and
right arrows to change the option.
Explanation of the Status codes in the upper right corner
It is important to observe the status messages in the upper right of the screen.
WAIT The unit is busy and will not respond immediately to your commands.
ACQ The receiver is acquiring signals from one or more satellites.
TRK The receiver is tracking at least one satellite.
For the following 4 digit codes, the fourth number (#) always represents the current PDOP. A
PDOP of 4.4 will appear as the number 5 (it rounds up).
N2D# The receiver is collecting data from ≥ 3 satellites, and can provide a 2D coord inate.
N3D# The receiver is collecting data from ≥ 4 satellites, and can provide a 3D coord inate.
F2D# The receiver is logging feature data to a file in 2D mode.
F3D# The receiver is logging feature data to a file in 3D mode.
The D will become a C when the receiver is detecting the RTCM beacon signal that it uses for
real-time differential. If the code does not say N3C# or F3C#, then you are not collecting submeter data. Also, if the PDOP is greater than 6, the receiver will not log sub-meter data.
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Before you leave
1. Check the status of the Alto batteries:
4 Turn the Alto ON.
4 Press the ON button a second time (may take a moment).
4 The % charge status of the two batteries is displayed on the screen.
4 As long as the two percentages add up to more than 40%, you will be fine. If you are
going out for a full day the two percentages should add up to at least 100%.
2. If you are collecting real-time differential data, make sure you have the backpack. It is
highly advisable to take the unit out to the sundial and make sure you are able to acquire
the real-time sub-meter corrections (see below for detailed instructions).
How to check the battery power in the Alto-G12
1. Press the ON button. Wait for a few seconds while it initializes.
2. Press the ON button again. If nothing seems to happen, wait a few more seconds.
The battery status is listed as:
BATT PACK 1(%): 54
BATT PACK 2(5): 58
(100 % = a full charge).
3. Press the ESC key to go back to the main menu.
4. Press F1 to turn the Alto off.
How to check the battery in the backpack
You can’t. If the battery is low, you will not get sub-meter locations because the receiver in
the backpack will not work. The symptom of a low backpack battery is that the units will not
detect any satellites, and the status indicator (in the top-right of the screen) will just say ACQ.
The battery should be fully charged before you check it out. If you are just using one or two
units, I recommend checking out a spare backpack battery too (we have 10 spare).
If the battery is connected, it is being drained. BE CERTAIN THAT THE BATTERY IS
DISCONNECTED WHILE YOU ARE NOT USING IT.
Check the Setup parameters on the Alto-G12
1. Press the ON button. Wait for a few seconds while it initializes.
2. At the Main Menu, use the ↑/↓ keys to select “Setup” and press ENTER.
3. Use the ↑/↓ keys to select “Datum/Coord. System.” Press ENTER.
4. Check the DATUM is WGS84, and the COORD is your preferred coordinate system: either
LLA (Lat/Long), SPC
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(State Plane Coordinates) or UTM (Universal Transverse Mercator). If
you don’t know what you need, use LLA.
5. Press F4 (SAVE).
6. Advanced users may also want to check the setup options under “Receiver”. Of particular
importance is the PDOP setting, which represents the maximum allowable PDOP. Ideally
this should be set to 6, but if you are having trouble acquiring points, you can try setting it
to 7. Never set it higher than 8!
[NOTE: see pages 29-28 of the instruction manual for detailed setup instructions.]
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If you select SPC, you must also define the STATE.
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USING THE ALTO-G12
R
To hook up the real-time differential receiver
There are 4 cables you need to hook up. (Please try not to let the cables touch the ground as
you are hooking them up.)
Antenna cable (black),
must be attached to
white antenna.
aise the antenna pole
so that it is above the
Three cables emerge
level of your head.
from the top of the
backpack, two of which
come over your left
shoulder.
Antenna cable (brown),
attaches at the top of
the Alto-G12.
Power cable (black),
must be plugged into a
COM port cable (beige),
attaches to COM2 on
top of the Alto-G12.
battery. Unzip the
backpack to access this
cable.
For real-time, sub-meter
locations, attach the COM port
cable to COM2, and the antenna
To use the Alto-G12 without the
real-time differential, use the
built-in antenna as shown.
cable to the connector as shown.
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