The only sub-meter ruggedized hand-held GPS/GIS receiver on the market    

An excellent unit for precision agriculture, hydrographic surveys, and utility mapping.

Signal inaccuracies are removed with RAIM (Receiver Autonomous Integrity Monitor). The built-in strobe correlator technology provides unmatched multi-path mitigation for code.


A proven and reliable GPS unit for GIS applications.




















List Price:





GPS receiver:

12 channel

12 channel



DGPS Beacon Receiver:





Professional GPS/GIS:





Mapping Accuracy:
(Differentially Corrected, 2DRMS)

C/A Code:  50 - 90 cm
Carrier Phase:   2 cm + 2 ppm included



Designed for easy use:

Yes, CMT Field 3.8 Included



On-board Traverse:





Post Processing:






4 MB standard
8 MB optional

4 MB standard
8 MB optional



Records Points, 
Lines, and Areas:





GPS/GIS Mapping Software:
Microsoft Windows® based 

Yes, PC-GPS 05 Included




Yes, submersible

Yes, submersible



       Audible beeper signal:















System Features
- 12-channel L1 frequency
- Strobe Correlator technology
- Full wavelength carrier phase on L1
- Carrier-phase smoothing
- RTCM-104 Ver. 2.2 input
- NMEA 0183 Ver. 2.2 output
- 1 PPS timing signal










NMEA / Barcode Device Interface Capabilities
- Two 9-pin RS-232 serial ports, PC/AT pinout.
- The ALTO-G12 has two waterproof DB-9 RS-232 serial ports (COM1: and COM2:) for communication with your PC as well as a variety of additional input and output devices such as:

RTCM-104 Version 2.0: Real-time DGPS 
Simply plug your RTCM-104 source (i.e. FM pager, VHF radio, WADGPS) into the ALTO-G12's COM1: port. The ALTO-G12 will automatically detect and use the RTCM message. Since the ALTO-G12 has two DB-9 serial ports, you can use COM1: for RTCM and still have COM2: available for a barcode reader or NMEA output to another instrument. Don't worry if you lose the RTCM message while you are collecting data; the ALTO-G12 can be set to collect raw data and will automatically warn you so you can post-process your data.

Compatible with Coast Guard Beacon Receiver  
Obtain real-time differential correction with CMT's Coast Guard Beacon Receiver package.

NMEA 0183 output 
The ALTO-G12 will send out a NMEA 0183 message, at an interval specified by you, to either COM1: or COM2:. This functionality allows the ALTO-G12 to output a GPS position to devices (i.e. digital cameras, sonar, etc.) that will accept a NMEA 0183 message. There is no need to change your instrument settings. The ALTO-G12 communications can be set to match your instrument. In the NMEA Setup screen, you have complete control over the baud rate and protocol settings.

Efficient Data Entry with Bar Code Input  
Attach a bar code scanner to the ALTO-G12 and you can quickly enter data. Bar code menus can be set up in such a way that you never need to touch the ALTO-G12 keyboard.









Data Collector Features
- Waterproof (submersible)
- Operating temperature: -40°C to 54°C
- 16 line x 25 character backlit display
- 4 MB RAM standard (8 MB optional)
- Fully integrated GPS receiver, antenna and data collector in one hand-held unit
- 55-key alphanumeric keyboard including 5 function keys and separate numeric keypad
- Optional external antenna
- Field-replaceable rechargeable battery
- Up to 8 hrs. operation on rechargeable batteries









CMT Field Software v3.8
- Collect Points, Lines Areas
- Feature/Attribute/Value GIS structure
- Graphic plotting.
- Traversing keyboard data entry to allow you to continue mapping when GPS is obstructed
- Offset function to map hard-to-reach locations.
- Nested point function for tagging points while you are mapping a Line or Area Feature.
- Averaging function to optimize accuracy while recording static points.
- LLA/UTM/SPC plus user-defined coordinates.
- Supports 50 datums plus user-defined datums.
- Provides area calculation in the field
- Interfaces to laser rangefinders, barcode readers and various NMEA devices
- Canyon, Blockage and Clear modes for optimal tracking performance

Obtain 2 cm + 2 ppm accuracy with Carrier Phase
Using carrier phase, the ALTO-G12-CM can attain centimeter-level accuracy (2cm+2ppm) without separate data collectors, antennas or poles. Uploading and processing your carrier phase data in PC-GPS is virtually the same as processing C/A code data. Behind the scenes, however, is a robust carrier phase processor (CMTCM) that will provide either a FIXED solution (ambiguities fixed to integers) or FLOAT solution (ambiguities resolved to real values). The program will notify you of which type of solution was used. You may also process the same data with the standard C/A code processor.

The ALTO-G12-CM offers the ultimate in flexibility, allowing you to do a variety of tasks. It can be used to record 1-3 meter data in addition to 2cm+2ppm data. For example, if you have a job that requires 2cm+2ppm accuracy on the property corners but only requires 1-3 meter accuracy on the streams running through the property, the ALTO-G12 would be the perfect tool. It can perform both tasks in the field without skipping a beat. In the past, you would have needed two different types of GPS receivers to do this job.









The ALTO-G12 package includes CMT's PC-GPS software for comprehensive GPS project management and mapping. PC-GPS 05 provides functions for Mapping, Mission Planning, Batch Differential Correction, Static Point "Spread" analysis and Job Editing. The software also supports GIS layering, raster images (i.e. DOQs, DRGs, aerial photographs, satellite imagery), multimedia objects (OLE 2.0) and Microsoft® ODBC.

System Accuracy Specifications

Real-Time Differential (DGPS):


40 cm


90 cm

DGPS (typical)

60-100 cm



L1 Carrier Phase Post-Processing:

Static (RMS)

2 cm + 2 ppm

Static (typical) 

1 cm + 2 ppm



L1 C/A Code Post-Processing:

Static (RMS)

40 cm

Static (2DRMS)

90 cm

Static (typical)

50-90 cm

Time to first fix

45 sec. typical, 20 sec. with current ephemeris


2 sec.

Sustained acceleration


Velocity (RMS)

.05 m/sec.

Maximum velocity

460 m/sec.

Maximum altitude 

18000 m










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