Thank you in advance for participating in this survey. Internet email is the preferred method of information sharing, but any format will be appreciated. Please send results to either lhothem@usgs.gov or Sally.Frodge@ost.dot.gov. The survey itself and pertinent results from the survey will be shared on the Commission 5 web site at http://surveying.wb.psu.edu. For those that participate and provide information, information of interest will be shared with them. The report will be shared with them directly. contact will be maintainedThe major categories for the survey are the areas of:
Systems: Many nations are establishing national systems based wholly or in part on GPS. There are related systems that may be augmented or replaced by the implementation of GPS based systems. This section of the survey is to determine the worldwide status in this area. Systems include direct service provision as well as supporting systems, such as reference systems.
Standards : Although many private providers and developers may prefer the use of their own proprietary formats, standards play an important role for systems and systems integration. This section of the survey is to determine the extent to which certain standards development efforts have progressed and FIG involvement in their development.
Spectrum :Most modern systems are based upon the use of spectrum. GPS, for example, uses radio waves in the L-band. The organization of the management of spectrum varies from nation to nation. The Mobile Satellite Services (MSS) have already affected the location of GLONASS frequencies. It is critical to have a good understanding of how spectrum is managed and what the links to the surveying community are in FIG member nations.
Applications : The breadth and range of GPS based applications has grown rapidly.
Please provide data and/or a point of contact/email address for information on the pertinent systems asked for. If you feel any are missing, please contact us with the added input.
i. Who maintains this system?
ii. How is data distributed from this system?
iii. Can anyone acquire this data by request? If yes, what is the address? If no, who is allowed and is there any special dispensations that are made for exception
Please answer any of the same questions from above that are pertinent here.
Please answer any of the same questions from above that are pertinent here.
i. Who maintains this system?
ii.How is data distributed from this system?
iii. Can anyone acquire this data by request? If yes, what is the address? If no, who is allowed and is there any special dispensations that are made for exceptions?
Please answer any of the same questions from above that are pertinent here.
Please answer any of the same questions from above that are pertinent here.
i. Who maintains this system?
ii.How is data distributed from this system?
iii. Can anyone acquire this data by request? If yes, what is the address? If no, who is allowed and is there any special dispensations that are made for exceptions?
Please answer any of the same questions from above that are pertinent here.
Please answer any of the same questions from above that are pertinent here.
For any of these sections, if you can provide the information, thank you in advance. If you cannot, please at least try and enter a reference person, with contact in formation such as their Internet email address.
Describe the major systems that are regional, national, or international in scope that are in place or going into place that are GPS based. For example, Canada has implemented the Active Control System. The United States Department of Transportation's (USDOT) Coast Guard has put into place the Differential GPS system. The USDOT's Federal Aviation Administration (FAA) is moving forward with the Wide Area Augmentation System (WAAS) to provide initial capability by 1998. To cover more stringent requirements the Local Area Augmentation System (LAAS) is being developed. The U.S. Department of Commerce's National Geodetic Survey (NGS) has implemented the Continuously Operating Reference System (CORS) that provides data from a number of stations placed around the world.
Although any information in any format is appreciated, it would be very beneficial if at least the following were included (using the USDOT Coast Gurad system as an example):
System :United States Department of Transportation / Coast Guard Differential GPS Radiobeacon System
Requirements Met by this system :
US Coast Guard had an unmet requirement for harbor/harbor approach of 8- 20 meters, 2 drms, horizontal. The U.S. Coast Guard developed this augmented GPS system to meet this requirement.
Supporting Authoritative Documents:
USDOT/USDoD Federal Radionavigation Plan (FRP). This document is published jointly by the U.S. Department of Transportation (USDOT) and the U.S. Department of Defense (DoD) on a two year cycle. The radionavigation systems used by the departments, and the policy regarding them, are described within this document.
RTCM etc
Others
Frequencies Used (if any):
This was designed to used only the GPS L1 frequency, although to support reqruiements of the U.S. Army Corps of Engineers (USACE) for hydrographic surveying and National Geodetic Survey (NGS) for the Continuously Operating Reference System (CORS), dual frequency GPS receivers were employed. It also uses radiobeacons to transmit differential GPS corrections to users. The frequencies for the radiobeacon system ranges from 285-325 kHz.
Basic Description :
The system uses GPS receivers at the primary reference station and at the integrity monitoring station. There is dual redundancy. The station generates a GPS correction, which is transmitted to users in Radio Technical Commission for Maritime (RTCM) format through the radiobeacon tower. Integrity of the system is on the send side. The message will not be sent if a problem is detected. Intergrity on the user side must be implemented by the user.
Correciton, format and data rate :
DGPS correciotns are sent in Radio Technical Commission for Maritime (RTCM) format. The minimum data rate is 100 bps, with newer stations coming on line at 200 bps.
Performance to date :
Although designed to meet the 8-20 m requirement, the system has performed much better. This has led the U.S. Coast Guard to change the system accuracy to 8-10 m. These changes are descrived in the FRP mentioned above. System performance has been consistently as low as 1-3 m, horizontal, based upon use of dual-frequency GPS receivers.
Connections to other systems :
The positions of the US Coast Guard sites are reference on the North American Datum of 1983 (NAD 83). The sites were surveyed in by the NGS. The data from the stations is fed into the CORS of the NGS. All USCG DGPS sites are part of the CORS national network.
The United States Coast Guard Navigation Center:
http://www.navcen.uscg.mil
The US NGS
http://www.ngs.noaa.gov