I did some checking after reading Chris Billingsley's post below on needing some help with GPS in Mississippi. I had just checked some MS data a month ago for Jimmy Cleveland. A CORS I used last monthe MSST is listed as decommisioned and not even on the NGS CORS map. In addition another MS CORS OKOM is listed as non-operational. This leaves Mississippi with only 8 active CORS.
Mississippi is slightly bigger than PA and since I have been doing my own GPS 910 years) I cannot PA ever having only 8 CORS. Currently there are 25 CORS in PA but 3 are listed as non-operational. Besides that PA is surrounded by states with many CORS. I will give numbers of those CORS along the PA perimeter:
Delaware 2, Maryland 5, New Jersey 6/8 (2 non-operational), New York 9 (while not near the border MVCC, Mohawk Valley Community College is non-operational), Ohio 5 and West Virginia 2/3 (1 non-operational).
As I was typing this Chris Billingsley sent his L1 RINEX files and I started another GNSS Solutions VRS project in Mississippi. I am happy to note that GNSS Solutions did not put MSST (decommissioned CORS) in my choice list. I was not happy that data from MSB1, MSB2, MSCD, MSCL and MSGV was not avaialble.
With L1 GPS the closer the CORS the better, but I will see what I can do.
Any comments on non-operational CORS from board members.
Paul in PA
That's what I was running into. All of the nearest CORS stations were listed as unavailable, so I thought perhaps I was doing something wrong and decided to get some help.
Talk to a NGS advisor for all the details but the requirements to maintain a cors are HUGE and unwavering. We had a local cors that has been active for years, change the name and instantly they treat it as a new station. Stations with less than one year opp time don't typ get thrown into the mix, etc, etc. If the mount is changed. It has to restart, name changed, restart. You may have to go to the individual site and download the files manually vs through the cors page.
Non-Operational CORS? Get involved.
LSU has over 67 CORS in our "C4G" Real-Time Network. Many are National CORS sites, but note that NGS has specific criteria for accepting new CORS sites that include minimum spacing distances. If a CORS site is operating within 70 km (I think), NGS is not likely to accept a new CORS.
LSU has had one CORS (network-only site) out in the Gulf of Mexico (on a stiff-leg oil platform) for a number of years, and we were recently informed by NGS that they want to now list it as a National CORS because it is a "unique" site.
It is tough keeping all of our CORS network up and running. We have one full-time employee that does only that for the entire State of Louisiana. That takes a lot of money for staff and maintenance personnel, and it ain't cheap. NEITHER the State of Louisiana nor LSU support us; we operate on subscription fees from our clientele.
The man running the CORS shop at NGS is Dr. Giovanni Sella, an LSU Ph.D. graduate.
