GPS: Decimeter

"XRT": Decimeter Accuracy

It’s now possible to obtain decimeter (10cm/4in) horizontal accuracy without a survey-grade receiver! This is also the first mapping-grade unit from Trimble with a vertical specification (as high as 10cm/4in). It is also possible to achieve this level of accuracy in the field without post-processing. However, post-processing is an option. Some GIS and Utility applications require decimeter but do not require survey-grade (1cm) accuracy. The ProXRT from Trimble addresses this area in between the survey-grade and the traditional “submeter” where GIS accuracy was previously defined. A common application for decimeter accuracy is the mapping of and navigation to underground facilities, critical infrastructure, and utility features. Please note that the decimeter level of accuracy can be obtained after post-processing with a license of Office Software or through use of a real-time correction source such as VRS or Omnistar HP (see below). Post-processing corrects the data, making it much more accurate and providing useful GPS metadata (quality control information) (Post-Processing White Paper). The capability to achieve decimeter accuracy is through a special form of Post-Processing known as “H-Star” (H-Star White Paper).

Please note that in a hostile GPS environment decimeter accuracy may not be possible such as (tree canopy, urban canyons, next to buildings, etc.) . In such environments, it is best to use these devices as a sub-meter unit. Achieving decimeter accuracy with the ProXRT is not automatic. It requires careful consideration to field and office techniques in order to achieve this accuracy. Seiler recommends placing the included Zephyr GPS antenna on a pole to achieve best accuracy. Also, Seiler recommends staying on each point for at least two minutes to help ensure that decimeter field requirements are met. In some cases, it may be required to be viewing 5 or more satellites for up to 60 minutes during a data collection project in order to get decimeter accuracy in the field. GLONASS will help achieve lock on satellites in a hostile environment. It is important to pay attention to your base station distance and the horizontal datum used. Read the H-Star White Paper and H-Star (Subfoot) Processing Tips and make sure that you understand and accept what is required to reliably and consistently achieve sub-foot decimeter accuracy. Seiler offers comprehensive training to cover H-Star and Decimeter topics.

ProXRT

The ProXRT is a decimeter (10cm/4in) GPS receiver. It is designed to stream GPS data to an appropriate Data Collector and Field Software of your choice. This allows you to choose a custom data collector. This is useful if you need a full-text keypad or wish to deploy a full-screen pen-tablet computer or laptop in the field. The ProXRT has integrated Bluetooth® to allow for cable-free connection to your Bluetooth-equipped data collector. If no Bluetooth is available, there is the option to use a 9-pin serial cable. The ProXRT also has an internal all-day battery. The ProXRT is designed to be mounted to the side of a pole or placed within a backpack. The included Zephyr model 2 antenna has a 5/8” screw thread adapter for easy mounting to a range pole or backpack.

• Real-time H-Star® technology for decimeter (10cm) or subfoot (30cm) accuracy in the field (requires being 30km from base station for decimeter and 30km-80km for subfoot).
• H-Star capable for sub-foot or decimeter accuracy upon post-processing with a license of Office Software
• Omnistar HP (Decimeter), XP (Subfoot), or VBS (Submeter) Technology for worldwide high accuracy in the field (Requires an appropriate level of Omnistar subscription and initialization times in the field of between 20-40 minutes for Omnistar HP or XP)
• Where available, tie into Seiler’s Midwest RTK Network to achieve Decimeter accuracy without the initialization time required by Omnistar (Requires a MWRTK subscription with Seiler and a customer-supplied cellular connection/data plan with a wireless carrier)
• Built-in WAAS for submeter accurate navigation WAAS White Paper
• Optional support for GLONASS for better tracking in areas with heavy tree canopy or near buildings.  Typically adds 3-4 satellites to the calculation.  Only for in-field use as GLONASS cannot be post-processed with the ProXRT.
• EVEREST® multi-path rejection for better accuracy results in harsh GPS environments
• Rugged receiver able to work in extreme temperatures with an internal all-day battery (13 hours)
• Built-in Bluetooth for cable-free operation
• Choice of field device, field software, and setup style to suit your requirements
• One-year Hardware Warranty is included

ProXRT Datasheet 

ProXRT Customer FAQs

Seiler’s Midwest RTK Network

GeoXH (2008 Series)

The GeoXH (2008 Series) is an integrated subfoot GPS/Data Collector that can accommodate your choice of appropriate Field Software. It can achieve decimeter (4in) accuracy when used with an external Zephyr antenna and when within 18 miles of a base station. Due to the high-accuracy nature of this combination, Seiler recommends that the antenna be mounted to a pole.

• • Windows Mobile 6.0: Secure data and built-in productivity tools
• 1GB on-board memory
• 128MB RAM
• H-Star® capable for sub-foot accuracy post-processed or in the field dialed into a VRS (decimeter accuracy with a Zephyr antenna)
• Removable SD/SDHC card slot: For customized memory expansion up to 32GB
• TFT Screen (480x640 pixel): An exceptionally crisp touch screen for map viewing that’s visible outdoors
• Bluetooth®: Wireless connection to peripheral devices
• Wi-Fi (802.11b/g): Wireless connection to the Internet, network, or supported camera
• EVEREST® multi-path rejection for better accuracy results in harsh GPS environments
• Built-in WAAS for submeter navigation (WAAS White Paper)
• One-year Hardware Warranty

GeoXH 2008 Datasheet
GeoXH 2008 FAQs
GeoXH 2008 Real-Time H-Star Accuracy (requirements to achieve decimeter accuracy in the field)