Attention all GPS gurus ...........

> Do solar flares like this affect the use of GPS for cadastral surveying purposes ?
> MAJOR FLARE: Earth-orbiting satellites have detected the strongest solar flare in more than four years. At 0156 UT on Feb. 15th, giant sunspot 1158 unleashed an X2-class eruption. X-flares are the strongest type of x-ray flare, and this is the first such eruption of new Solar Cycle 24. The explosion that produced the flare also sent a solar tsunami rippling through the sun's atmosphere and, more importantly, hurled a coronal mass ejection toward Earth. This raises the possibility of geomagnetic storms in the days ahead. Visit> http://spaceweather.com """
yes, i believe it does affect gps signal. as for cadastral, specifically, your mileage may vary. i will try to check it out, and get back to you.

from ngs power point by Bill Henning:
"SINGLE FREQUENCY USERS USE A MODEL FOR IONO CORRECTIONS, SO DURING GEOMAGNETIC STORMS, THEY WILL EXPERIENCE MORE DRAMATIC ERROR AND NOISE THAN DUAL + FREQUENCY USERS WHO MAY USE THE DISPERSIVE CHARACTER OF THE IONOSPHERE TO CALCULATE THE ACTUAL ERROR."
i found the above quote just now, looks like it will be in WVPLS speech next week

ftp://www.ngs.noaa.gov/dist/whenning/WVSPS2011/RTFIELDGUIDE.WV2011.pdf

other reading:
GEOMAGNETISM AND SOLAR STORMS

FROM: http://www.ngs.noaa.gov/CORS/GPS_Bibliography/GPS_bibliography_2006.shtml

Li G, Ning B, Wan W, Zhao B (2006) Observations of GPS ionospheric scintillation over Wuhan during geomagnetic storms. Ann. Geophys. 24(6): 1581-1590

Afraimovich EL et al. (2006) An investigation of the correlation between ionospheric and geomagnetic variations using data from the GPS and INTERMAGNETIC networks. Adv. Space Res. 38(11): 2332-2336

de Abreu AJ et al. (2010) Response of the ionospheric F-region in the Brazilian sector during the super geomagnetic storm in April 2000 observed by GPS. Adv. Space Res. 45(11): 1322-1329

de Jesus R et al. (2010) Effects observed in the ionospheric F-region in the South American sector during the intense geomegnetic storm of 14 December 2006. Adv. Space Res. 46(7): 909-920

Li GZ et al. (2010) Longitudinal development of low-latitude ionospheric irregularities during the geomagnetic storms of July 2004. J. Geophys. Res. 115(A04304): 1-17

Wang WB et al. (2010) Ionospheric response to the initial phase of geomagnetic storms: Common features. J. Geophys. Res. 115(A07321): 1-18

Wen DB, Yuan YB, Ou JK, Zhang KF (2010): Ionospheric response to the geomagnetic storm on August 21, 2003 over China using GNSS-based tomographic technique. IEEE Trans. Geosci. Remote Sens. 48(8): 3212-3217

Here's a 1:16 video of the event. (you can dance to it too, if you like 🙂 )

It's a big one.

http://video.godlikeproductions.com/video/Earth_Directed_X22-Class_Solar_Flare_and_bright_CME_Feb_15th_2011?id=4e81afd498b8e8f0f71

There will no doubt be some spectacular Aurora's come out of it though.

That's the upside. The downside is it will screw with your GPS (and many other things like military electronics, etc.)

There is a definite spike in support calls on those occasions.

My bad

I thought it said "GPS Gnus"

Like all other surveying related issues... the answer is "it depends".

Here is another list of good articles on the topic of Space Weather and GPS/GNSS:

A Beginner's Guide to Space Weather and GPS
(For GPS engineers and systems designers)

Space Weather Effects on GPS

Space Weather – Monitoring the Ionosphere with GPS

GNSS and Space Weather – Making the Least out of Solar Max

Solar Cycle 24 and its impact on GNSS positioning

Scott

TUVM

Derek