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tosborn

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  1. After going down the list of highest points in Monroe (overpasses, mounds in gravel yards, and a backstop for a rifle range), I believe the highest natural area is the plateau of sorts that includes tri-station Sicard (CQ2664, N32.53019°, W092.01085°, NAD83) at an elevation of about 95 feet. The tri-station is actually just outside the city boundary. So inside the boundary look at N32.53047°, W092.01431° or somewhere nearby.

     

    NGS lists tri-station Sicard as destroyed, but the circumstances seem odd. On Jan 1, 2011 GEOCAC recovered the station disk and two surviving reference marks but not the azimuth mark. On the very next day, NGS reported the station as destroyed with no explanation. Might be worth a trip to see what is or isn't there.

     

    For West Monroe, it looks like the highest natural point within the city boundary (US Census) is at or near N32.50650°, W092.19290°. The topo map shows three enclosed 150 foot elevation contours there. However, the northerly one is at the exit and entry ramps of Interstate 20 and so may have been affected by construction.

  2. Travis:

     

    I brought the boundaries of West Monroe, and Monroe into my GIS program and overlaid them on USGS elevation contour data and National Elevation Data. It appears that the high points in both cities are overpass embankments.

     

    For West Monroe the high point is at 32.51138, -92.19194 (NAD83 Lat, Long) at an elevation of nearly 157 feet. There is an NGS Datasheet for a survey disk in the overpass roadway. It's PID is CQ2678.

     

    For Monroe the high point is at 32.5181, -92.07986 (NAD83 Lat, Long) at an elevation of nearly 103 feet. The nearest PID for this point (CQ3431) is .3 miles away.

     

    Hope that's what you wanted.

  3. Dave:

     

    What do you know about the history of the mini obelisk? It appears that it's PID is HV1841 and it was first recovered by NGS in 1971. The monumented date is unknown by the Department of Defense. Does this go back to the original construction of the Washington Monument? If it is more recent it seems like it would have been a lot easier to just drive a rod rather than create a 12 foot tall buried version obelisk.

     

    Enjoyed the podcast.

     

    Tim Osborn

  4. I think this reads such that "North" and "East" are relative directions with respect to the highway. So, this is how I would interpret it: at the point of intersection between the highway and the railroad, proceed 74 feet perpendicular to the direction of the highway in a Northerly direction (based on Topo maps that would be a true azimuth of about 348.3 degrees). Then, from that point go parallel to the highway 117 feet in an Easterly direction. That puts you almost exactly on top of the BM X on the topo map. You'll cross over the tracks on that second leg.

  5. Based on your comments, that claim is suspect. It would seem that that a property corner would not necessarily fall on a GLO PLSS?

     

    The General Land Office Public Land Survey System (GLO PLSS) was all about marking corners so that the public lands could be homesteaded or sold into private property. Entrymen took possession based upon the PLSS corners. If the landowner you referred to owned the 40 acre quarter-quarter immediately to the southwest of this corner, then it surely was his NE property corner. If he only owned the next quarter-quarter to west, then he was probably mistaken.

  6. No. The Datasheet folder contains the most recent monthly State Archive files in textual format. The Archive folder contains the archived Archive files....in other words, last month's textual format Archive files. That's why I said the word "archive" has two meanings.....1) a statewide snapshot and 2) last month's files.

  7. That's correct. Important data items for benchmarking that are not in the shapefiles are monumentation type (e.g. benchmark, triangulation station, tower, etc), stamping, box scores, setting, and "to reach" info. The following fields are what the shapefiles include:

     

    DATA_DATE - date the archive was prepared

    DATA_SRCE - URL of the datasheet

    DEC_LONG - decimal longitude

    DEC_LAT - decimal latitude

    PID

    NAME

    STATE

    COUNTY

    QUAD - USGS quadrangle containing mark

    LATITUDE - degrees, minutes and seconds

    LONGITUDE - ditto

    POS_DATUM - NAD83

    DATUM_TAG

    POS_SRCE - scaled, adjusted, HH

    ELEVATION

    ELEV_DATUM

    ELEV_SRCE

    ELLIP_HT

    ELLIP_SRCE

    POS_ORDER

    POS_CHECK

    ELEV_ORDER

    ELEV_CLASS

    ELEV_CHECK

    DIST_RATE

    ELLP_ORDER

    ELLP_CLASS

    FIRST_RECV - first recovery date

    LAST_RECV - last recovery date

    LAST_COND - good, not found, etc

    LAST_RECBY - agency for last recovery

    SAT_USE - satellite visibility

    SAT_DATE

    STABILITY

  8. The NGS database is constantly changing....new recoveries, new marks, marks classified as destroyed, etc. Once a month on a particular day for each State, NGS takes a snapshot of all non-destroyed PIDs. They call this an archive since, on the very next day, one or more datasheets may be different due to new recoveries, new marks, etc. The archive can be either in textual datasheet format (Datasheets folder), or they can be in shapefile format (Shapefiles folder). After a month, they create new archive files for the State, and save the previous month's textual datasheet archive in the ARCHIVE folder. The previous month's shapefile archive is saved in an Archive folder under the Shapefiles folder. So there are really two meanings of archive involved. But archive doesn't mean destroyed or inactive.

  9. In checking the NGS database this evening I see a November 20, 2010 GEOCAC "MARK NOT FOUND" report for FAWN by FSC. That's pretty recent. Are you perhaps FSC? If not then its too soon for another report unless you have different recovery results.

  10. http://www.mappingsupport.com/p/gmap4.php?z=15&t=t2&icon=ch&ll=36.15438,-94.23657

     

    Replace the coordinates at the end of the above URL with your hand-held coordinates (lat,lon) and view in your browser. A crosshair icon will be placed on the map at the location of your coordinates.

  11. Dave:

     

    Here are 13 PIDs for Arkansas. They should constitute all of the adjusted marks in Arkansas with an incorrect County Name. I didn't see any point in checking scaled marks(coordinate accuracy) or intersection stations(relevance). I have checked each of these 13 against Bureau of the Census Arkansas county boundaries for 2010 and USGS 1:24,000 topo maps.

     

    PID      WrongCounty    CorrectCounty
    DG4779     CHICOT         DESHA
    DK2001     DESHA          CHICOT
    DK2009     DESHA          DREW
    DL1575     MILLER         HEMPSTEAD
    EH0993     LEE            PHILLIPS
    EH2912     MONROE         PHILLIPS
    EH3062     PRAIRIE        LONOKE
    EH3076     PRAIRIE        LONOKE
    EH3117     LEE            ST FRANCIS
    EJ1878     PERRY          PULASKI
    EJ1911     SALINE         GARLAND
    EK0817     SCOTT          POLK
    FF1965     MISSISSIPPI    CRITTENDEN
    

     

    Tim

  12. Deb recently clarified that she would prefer to receive no reports of any kind concerning intersection stations such as KS1902. If you found the displaced disk from KS1126 then you could send a photo to Deb to have it classified as destroyed, otherwise the convention is to report it as not found.

  13. It appears that the coordinates are Mass Mainland State Plane coordinates, NAD27 US feet. If so, they would translate to 42.347792473 degrees latitude by -73.119747542 degrees longitude (NAD83). This is a point near the intersection of Schulze Road and the Pittsfield Road. Schulze Road would be the "Y ROAD EAST." Elevation of 529 meters looks correct for this location on topo map. However this location is 2.25 miles Northwest of Becket...not 1.7 miles Northeast as description states.

  14. In late August we had a discussion (link) about reporting destroyed intersection stations (e.g. water towers, church steeples, etc) to NGS. It has been stated by some here that while NGS (Deb Brown) no longer wishes to receive positive recovery reports on intersection stations, destroyed interesection stations should continue to be reported to NGS so that they can be removed "from the active database to reduce clutter."

     

    Shortly after that discussion I emailed Deb Brown the following:

     

    Deb:

     

    In the past you've indicated that you would rather NOT receive GEOCAC

    recovery reports on intersection stations. Does that also apply to destroyed

    reports on intersection stations?

     

    The reason I ask is that there is currently an assumption among GEOCAC

    participants that while you DON'T want recovery reports on intersection

    stations, you DO want destroyed reports when there is evidence that the

    intersection station has been destroyed.

     

    Yesterday I received the following response from Deb:

     

    Sorry for the delay in responding.

     

    Typically I'd rather not get info of any sort on intersection stations

    or landmark stations, however, if I get them I process them. The advent

    of GPS has eliminated their use.

     

    deb

     

    So I would humbly suggest that we respect Deb's wishes and refrain from submitting info of any sort to NGS concerning intersection stations.

     

    Tim

  15. A spot elevation is a label on a topographic map that measures the vertical position of a point at less than third order accuracy. There is usually at least one spot elevation shown per square mile. You may see them at prominent tops, saddles, or depressions, intersection of trails and road, sharp turns in linear features, boundary marks, PLSS corners etc. The T indicates that this spot elevation was determined using photogrammetric methods...meaning it was not determined in the field but from aerial photography.

  16. Be careful with respect to using the metal detector if the area in question is within the bounds of the National Historic site. The National Park Service prohibits the use of metal detectors and will likely confiscate it unless you get their prior approval.

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