How to get lidar file on top of usgs map

[ashhafPE]

The lidar information was given to us in xyz format. I converted it using Geopak into .dat then .tin and got contours. However, when I tried to superimpose the contours with the USGS maps but they were way off. The USGS maps matched a file provided by the state. So I know the problem is with the lidar information. I am using Microstation V8.

 

[IRstuff]

Way off HOW?

If it's either offset or scaling, then there's a problem with the initial position coordinate or some problem in the definition of the ranges.

If it's something else, then you need to review the original data for errors.

TTFN

FAQ731-376

 

[ashhafPE]

Off by coordinates. Lidar has coordinates of 1196096.8537, 16610769.2215 while USGS has 50661.2560, 241901.5558.

 

[IRstuff]

Is that consistent with the raw data?

Did you do the conversion correctly?

If you've got bad data, then only thing you can do is to subtract the offset from your data.

TTFN

FAQ731-376

 

[tsgrue]

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What you are describing sounds like each dataset has distinct coordinate systems (probably based on different projections). Do you know that coordinates systems of the "USGS data" and the "LIDAR data"? It is rarely the case that a simple shift or correction factor will transform from one coordinate system to another. You may know this stuff already and I am not understanding your question. If not, here are some questions to get you started:

1) Are the data coordinates in units of US Survey Feet, International Feet, Meters, Decimal Degrees, Degree Minutes Seconds, or something else?
2) Did you receive metadata with the other data?
3) What are the data coordinate systems?

I suggest checking out the following sites:

National Geodetic Survey (NGS): Remote Sensing Division

http://www.ngs.noaa.gov/RSD/rsd_home.shtml

University of Washington: Introduction to Geographic Information Systems in Forest Resources

http://gis.washington.edu/esrm250/lessons/projection/

University of Colorado: Coordinate Systems Overview

http://www.colorado.edu/geography/gcraft/notes/coordsys/coordsys.html

Colorado State University: State Plane Coordinate System

http://www.warnercnr.colostate.edu/class_info/nr502/lg3/datums_coordinates/spcs.html

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tsgrue: site engineering, stormwater
management, landscape design, ecosystem
rehabilitation, mathematical simulation

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