[Geysers] People on Minute Man Geyser

[Steven Krause]

As I pointed out previously.....

That is current, survey grade equipment they were backpacking.

Yes, survey grade GPS equipment truly is accurate to less than an inch 
absolute position if they're using a properly calibrated base station. 
Accuracy is entirely subject to good survey technique to make sure 
jiggle does not affect the results significantly, although there are 
also certain averaging techniques that can also minimize that. (The 
particular unit in the photo appeared to be a Trimble R8 unit, their 
website cites the high accuracy mode as being +- 5mm with a .5ppm rms 
error band). One photo does not prove survey technique obviously.

Now, I'll admit that to my mind a better technique would have been to 
use that same GPS basestation and pair it with a survey instrument. 
About double to triple the number of field measurements required, more 
work to translate the measurements into absolute position, and more 
expensive due to the cost of the instrument, but that would provide a 
non-footprint solution to the problem of "where is that vent".

Steve Krause
Cranky engineer


SCOTT BRYAN wrote:
> Well, as I think I personally made rather clear, permit or not they 
> are (were) standing on a rare and delicate natural feature, and 
> whether they were "trained" or not, they caused damage to the 
> formation. Clearly, the NPS does not wish to admit to that. And, I 
> might add, why did the person writing the data also have to be on the 
> formation?
>  
> Anyway, I note this evening that the subject photo of Minute Man is 
> not longer on the website. My, my. But as Paul Strasser noted, check 
> out the photo of Mortar Geyser. Ah well, why don't I just attach it 
> before it, too, gets removed!
>  
> Those people were involved with the production of the Geothermal 
> Inventory that has gotten recent attention in these missives. As I've 
> noted, the NPS people seem to believe that their GPS positions 
> are accurate to the 1/10,000,000th of a degree -- for example here, 
> they cite Minute Man Geyser as being at latitude 44.3547549 [deg N] 
> longitude 110.7984134 [deg W]. As pointed out previously, it is [my 
> opinion again] rather dumb to presume that accuracy: 1 degree of 
> latitude is a bit more than 69 miles (1 degree of longitude is, too, 
> but only at the equator). So 1/10,000,000 of 69 miles (1 degree) = 
> approximately 0.437 inch of latitude and considerably less than that 
> of longitude. So what happens if the equipment jiggles just a little 
> bit....?]
>  
> OK, so I'm a Curmudgeon. But this ----- (errr, ticks) me off.
>  
> Scott Bryan
>
>
>     Subject: RE: [Geysers] People on Minute Man Geyser
>
>     Wild guess - they're most likely geologists, in the back country,
>     they have
>     a permit and are doing more accurate cartographic work?
>
>     Janet White
>
>
>