How to locate points on the surface above a survey station?
I would appreciate any suggestions regarding the best (easiest, quickest) way to locate points on the surface that directly overlie survey stations in the cave. For example, suppose we find a place in the cave with surface debris and would like to examine the surface directly above for an entrance or dig. The ideal solution would allow me to input surface survey data in the field using a laptop and would generate an azimuth and distance from the last station to the desired point. I've sometimes overlayed the cave map or lineplot onto a topo or satellite image to identify the general area, but I'm looking for a much more precise solution. Currently, I survey overland from the entrance toward the area overlaying the station I want to get above. As I get close, I temporarily rename the last surface survey station to the name of the station in the cave below. This tells Therion that I've closed a loop and it gives me the closure error in all three axes. The x and y axis tell me how close I am, and I can guesstimate an approximate azimuth for the next shot to get closer. This eventually gets me close, but it is subject to blunders and overly time consuming. Is there a better way, perhaps through some function of Therion with which I am unfamiliar? Thanks for any ideas. JP
The most accurate way is to use method named "radiolocation". In the simplest way you may use avalanche transceivers. Check: http://caves.org.uk/radio/bookinfo_02.html m.s. 2. 6. 2014 v 23:17, McLendonJP@aol.com:
I would appreciate any suggestions regarding the best (easiest, quickest) way to locate points on the surface that directly overlie survey stations in the cave. For example, suppose we find a place in the cave with surface debris and would like to examine the surface directly above for an entrance or dig. The ideal solution would allow me to input surface survey data in the field using a laptop and would generate an azimuth and distance from the last station to the desired point. I've sometimes overlayed the cave map or lineplot onto a topo or satellite image to identify the general area, but I'm looking for a much more precise solution. Currently, I survey overland from the entrance toward the area overlaying the station I want to get above. As I get close, I temporarily rename the last surface survey station to the name of the station in the cave below. This tells Therion that I've closed a loop and it gives me the closure error in all three axes. The x and y axis tell me how close I am, and I can guesstimate an approximate azimuth for the next shot to get closer. This eventually gets me close, but it is subject to blunders and overly time consuming. Is there a better way, perhaps through some function of Therion with which I am unfamiliar? Thanks for any ideas.
JP As a hack, how about temporarily making the survey station near the debris an entrance. Then an export to a cave-list will give you the coordinates directly. Eg export cave-list \ -location on \ -surveys off \ -output ../Output/MiddleEarthcaves.html Or of you use .kml extension you get a Google Earth file directly. I'm assuming you want the easiest way to walk to the surface location directly above the cave, and have a gps unit into which you can enter these as way points. Re-reading you question that might not be what you want. There might be other approaches using continuation flags, and or obtaining the coordinates from an sql export or from a model export to .3d and use Aven to obtain coordinates. Bruce _____ From: therion-bounces@speleo.sk [mailto:therion-bounces@speleo.sk] On Behalf Of McLendonJP@aol.com Sent: Tuesday, 3 June 2014 9:17 a.m. To: therion@speleo.sk Subject: [Therion] How to locate points on the surface above a surveystation? I would appreciate any suggestions regarding the best (easiest, quickest) way to locate points on the surface that directly overlie survey stations in the cave. For example, suppose we find a place in the cave with surface debris and would like to examine the surface directly above for an entrance or dig. The ideal solution would allow me to input surface survey data in the field using a laptop and would generate an azimuth and distance from the last station to the desired point. I've sometimes overlayed the cave map or lineplot onto a topo or satellite image to identify the general area, but I'm looking for a much more precise solution. Currently, I survey overland from the entrance toward the area overlaying the station I want to get above. As I get close, I temporarily rename the last surface survey station to the name of the station in the cave below. This tells Therion that I've closed a loop and it gives me the closure error in all three axes. The x and y axis tell me how close I am, and I can guesstimate an approximate azimuth for the next shot to get closer. This eventually gets me close, but it is subject to blunders and overly time consuming. Is there a better way, perhaps through some function of Therion with which I am unfamiliar? Thanks for any ideas. JP
If you generate kml output then you can read the lat-lon for any station from that. If you generate survex 3d output then you can read the coordinates of any station in the Aven viewer (part of the Survex install) in the grid coordinate system you defined for the data. Footleg On 3 June 2014 07:42, Bruce <bruce@tomo.co.nz> wrote:
JP
As a hack, how about temporarily making the survey station near the debris an entrance. Then an export to a cave-list will give you the coordinates directly.
Eg
export cave-list \
-location on \
-surveys off \
-output ../Output/MiddleEarthcaves.html
Or of you use .kml extension you get a Google Earth file directly.
I’m assuming you want the easiest way to walk to the surface location directly above the cave, and have a gps unit into which you can enter these as way points. Re-reading you question that might not be what you want.
There might be other approaches using continuation flags, and or obtaining the coordinates from an sql export or from a model export to .3d and use Aven to obtain coordinates.
Bruce
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*From:* therion-bounces@speleo.sk [mailto:therion-bounces@speleo.sk] *On Behalf Of *McLendonJP@aol.com *Sent:* Tuesday, 3 June 2014 9:17 a.m. *To:* therion@speleo.sk *Subject:* [Therion] How to locate points on the surface above a surveystation?
I would appreciate any suggestions regarding the best (easiest, quickest) way to locate points on the surface that directly overlie survey stations in the cave. For example, suppose we find a place in the cave with surface debris and would like to examine the surface directly above for an entrance or dig. The ideal solution would allow me to input surface survey data in the field using a laptop and would generate an azimuth and distance from the last station to the desired point. I've sometimes overlayed the cave map or lineplot onto a topo or satellite image to identify the general area, but I'm looking for a much more precise solution. Currently, I survey overland from the entrance toward the area overlaying the station I want to get above. As I get close, I temporarily rename the last surface survey station to the name of the station in the cave below. This tells Therion that I've closed a loop and it gives me the closure error in all three axes. The x and y axis tell me how close I am, and I can guesstimate an approximate azimuth for the next shot to get closer. This eventually gets me close, but it is subject to blunders and overly time consuming. Is there a better way, perhaps through some function of Therion with which I am unfamiliar? Thanks for any ideas.
JP
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