The most accurate L1 single-frequency GPS receiver (30 cm RMS) available. 

Carrier phase capable of achieving 1 cm + 1 ppm accuracy with long occupation times.  
Recommended by CMT for use as a very reliable, high-precision base station. 

When compared to Trimble Pro XRS, it provides better accuracy and a more powerful software solution. Efficient and Precise.

With a long base line distance, such as 300 KILOMETERS, and one minute of static measurements, you can achieve 30 CENTIMETER accuracy. Very useful for asset surveys.






List Price:




GPS receiver:

12 channel

12 channel


DGPS Beacon Receiver:




Professional GPS/GIS:




Mapping Accuracy:
(Differentially Corrected, 2DRMS)

C/A Code:  25 - 50 cm  
Carrier Phase:   1 cm + 1 ppm 


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
- Extremely stable pseudorange code & phase measurements
- Full wavelength carrier phase on L1
Carrier-phase smoothing
- Up to 2 Hz position update rate
- Up to 10 Hz code & phase measurements- 12-channel L1 frequency
- 1 PPS timing signal
Superior performance under tree canopy




NMEA / Barcode Device Interface Capabilities
- Two 9-pin RS-232 serial ports, PC/AT pinout.
- The HP-GPS-L4 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 HP-GPS-L4's 9400 GPS Receiver. The HP-GPS-L4 will automatically detect and use the RTCM message. Since the HP-GPS-L4 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 HP-GPS-L4 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 HP-GPS-L4 will send out a NMEA 0183 message, at an interval specified by you to COM2:. This functionality allows the HP-GPS-L4 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 HP-GPS-L4 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 HP-GPS-L4 and you can quickly enter data. Bar code menus can be set up in such a way that you never need to touch the PC5L keyboard.



PC5L Data Collector 
with CMT Field v3.8
- Waterproof (submersible)
- Operating temperature: -40°C to 54°C
- 4 MB RAM standard (8 MB optional)
- 16 line x 25 character backlit display
- Interfaces to laser rangefinders, barcode readers and various NMEA devices
- Two 9-pin RS-232 serial ports, PC/AT pinout







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 HP-GPS-L4-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 by simply selecting the CMT Differential processor.

The HP-GPS-L4-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 HP-GPS-L4 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 HP-GPS-L4 package includes CMT's PC-GPS software for comprehensive GPS project management and mapping. PC-GPS 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):


30 cm

DGPS (typical)

30 - 60 cm



L1 Carrier Phase Post-Processing:

Static (RMS)

1cm + 1ppm

Static (typical) 

20 - 50 cm



L1 C/A Code Post-Processing:

Static (RMS)

30 cm

Static (typical)

20-50 cm

Time to first fix

60 sec. typical, 40 sec. with
current ephemeris



Velocity (RMS)

.05 m/sec.

Maximum velocity

460 m/sec.

Maximum altitude 

18000 m




Operating temperature:

-20°C to 50°C


Power consumption:

6 watts


Input voltage:

10-32 VDC



95% non-condensing






Download a printable brochure here.