Originally posted by Bob 256 Something peculiar happened to me about two weeks ago. I was in the mountains and a cousin came to visit. We went on a road trip which took us up to a 9000 foot mountain top which had a beautiful scenic view. I had my K-1 and snapped away. I wanted to know what the exact elevation was (no markers) and assumed my K-1 would record the elevation. After I got home, I pulled up the data on that shoot, and to my surprise, there was no GPS data for the mountain top. Each and every one of my shots there lacked GPS data though shots before I got there and shots afterwards had it intact.
At first, I thought it was my fault for not giving the K-1 enough time to lock but some of those shots were almost a minute after I had the camera turned on. Then came the realization that there was a forest service repeater on the mountain top close to where I had taken all those shots. I think now that it was responsible for the lack of GPS info and in some way was creating interference that disabled the GPS reception in that area. There were no microwave dishes, however, but something on the site had prevented my K-1 from getting the data.
I finally had to resort to using Google Earth which gave me the elevation for the location
Anyone familiar with forest service repeater sites that can fill me in??
Highly unlikely that repeater is working on the frequency range of GPS. That would violate FCC rules and would be found quickly as it would interfere with aviation who would quickly notice.
It's possible there's a gap in the ephemeris file for the satellites (position locations) in that location (on the camera) or maybe a GPS jamming event if you have any military bases within a few hundred miles. The past few years they've been doing significant testing on GPS jamming equipment (Russia is really good at GPS jamming).
When it's the ephemeris file it's usually an outage in a small or sometimes large area for a few minutes to maybe 30 minutes. Or it could have been space weather blocking the GPS signal for a period of time.
https://www.swpc.noaa.gov/
FAA will GPS NOTAM an area if the military is testing. Those can be found linked below.
KZLC is Salt Lakes region. There is GPS outages notams within 400ish miles at the moment, possible in the timeframe you mentioned as well.
https://www.navcen.uscg.gov/pdf/gps/gpsnotices/GPS_Interference.pdf
10/120 (A0359/20) - NAV GPS (WSMRNM GPS 20-11) (INCLUDING WAAS, GBAS,
AND ADS-B) MAY NOT BE AVBL WI A 437NM RADIUS CENTERED AT
332930N1062835W (TCS059042) FL400-UNL,
392NM RADIUS AT FL250,
317NM RADIUS AT 10000FT,
311NM RADIUS AT 4000FT AGL,
294NM RADIUS AT 50FT AGL. 24 OCT 06:00 2020 UNTIL 24 OCT 12:00 2020. CREATED:
21 OCT 01:42 2020
10/103 (A0354/20) - NAV GPS (NTTR GPS 20-13) (INCLUDING WAAS, GBAS, AND
ADS-B) MAY NOT BE AVBL WI A 466NM RADIUS CENTERED AT 371934N1154249W
(BTY041059) FL400-UNL,
417NM RADIUS AT FL250,
340NM RADIUS AT 10000FT,
298NM RADIUS AT 4000FT AGL,
228NM RADIUS AT 50FT AGL. 23 OCT 06:00 2020 UNTIL 23 OCT 08:00 2020. CREATED:
19 OCT 05:34 2020
10/099 (A0353/20) - NAV GPS (WSMRNM GPS 20-11) (INCLUDING WAAS, GBAS,
AND ADS-B) MAY NOT BE AVBL WI A 437NM RADIUS CENTERED AT
332930N1062835W (TCS059042) FL400-UNL,
392NM RADIUS AT FL250,
317NM RADIUS AT 10000FT,
311NM RADIUS AT 4000FT AGL,
294NM RADIUS AT 50FT AGL. 23 OCT 08:00 2020 UNTIL 23 OCT 12:00 2020. CREATED:
19 OCT 02:37 2020
10/088 (A0352/20) - NAV GPS (WSMRNM GPS 20-11) (INCLUDING WAAS, GBAS,
AND ADS-B) MAY NOT BE AVBL WI A 437NM RADIUS CENTERED AT
332930N1062835W (TCS059042) FL400-UNL,
392NM RADIUS AT FL250,
317NM RADIUS AT 10000FT,
311NM RADIUS AT 4000FT AGL,
294NM RADIUS AT 50FT AGL.
DLY 0600-1200. 21 OCT 06:00 2020 UNTIL 22 OCT 12:00 2020. CREATED: 17 OCT 22:56
2020
https://www.notams.faa.gov/dinsQueryWeb/ Defense Internet NOTAM Service