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Taming the Survey Data "Tower of Babel"

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Presentation made at NJSPLS SurvCon08 February 2008.

Presentation made at NJSPLS SurvCon08 February 2008.

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Taming the Survey Data "Tower of Babel" Taming the Survey Data "Tower of Babel" Presentation Transcript

  • Taming the Survey Data “Tower of Babel” J. R. Lemuel Morrison, PLS Mercator Land Surveying, LLC
  • Taming the Tower Objectives: Highlight difference between the types of data collected Explain a framework to manage data both for inside the office and for clients Outcome: Show examples using AutoCAD LDD and other software . . . but first an introduction
  • J R Lemuel Morrison, LS
    • Buckeye
    • Licensed:
    • NJ, NY & OH
    • Instructor, Land Surveying
    • NYC College of Technology
    • President & Founder, Mercator Land Surveying
    View slide
  • The Premise
    • We can take measurements in more ways than before
    • There are more tools in the surveyor’s tool box
    Many more formats available for our deliverables Transmitting large files becomes easier every year – and will get easier However, when we combine data from different measurement types, are the ‘hazards’ being recognized and addressed? However, when we deliver the submittal to the client, do we provide them with all the data that might be helpful? View slide
  • Taming the Tower Data Round Up Examples The Pitfalls of Diverse Data Data Management During Drafting Data Collection, Analysis & Archiving
  • Looking Under the Hood
    • Will any of the data you collect be seen by the client?
    Is it direct? Does it need to be processed? Does it have depth? Is it from others? Will the client see it? Factors to consider when we collect data:
    • How was the data collected? Was it “touched” or obtained remotely?
    • Is the data type inherently different from each other? (angle/range, satellite, stereoscope, astronomic)
    • Do we collect more data than can be shown in a traditional survey? Is there information that we collected that is outside of our professional task? (point clouds, imagery or documents)
    • Are you showing data that you actually didn’t collect but may be responsible for?
  • Data Round Up Orig, Maybe CAD, yes Yes Yes Yes, Analysis n/a Deeds, Maps & Images Orig, Maybe CAD, yes Yes Yes Yes, Translation / Rotation & Analysis No Utilities Yes Yes Yes Yes, Translation / Rotation n/a Others (GIS, Gov, prev surveyor, othos) Yes Yes No No No Aerial Mapping Points, no CAD, yes No Yes No No Scan Data No No No Yes, Process and network adjustment n/a Astronomic / Gyro Points, no CAD, yes No No No, only to modify base (if needed) Yes GPS -- RTK No No No Y e s , Process & adjust network Yes GPS – Static Points, no CAD, yes No No Yes, Traverse & w/GPS Yes, except RL Conventional Client From Others Depth Process Direct Data Source
  • Data Roundup -- Conclusions Use the tools necessary to meet the client’s need and budget. Make sure the data is correct, adjusted, and properly combined. Keep the data archived (both raw and processed), while maintaining all the depth. Convey to the client (and others) what is required. Also let the client know that there is additional info. . . . Our primary function as surveyors is to show what we find. And to organize it and make it understandable! The more tools you use, the greater is the productivity and the complexity Data can be extremely precise, but complete inaccurate. You never know when you will need the originals & losing data during processing is a crime! A robust product will serve the client well and bring them back Surveyor’s Role Comments
  • Outline Data Round Up Examples The Pitfalls of Diverse Data Data Management During Drafting Data Collection, Analysis & Archiving
  • Data Collection, Analysis & Archiving Control (GPS-Static, Traverse & Gyro) Deeds, Map & Images Aerial Mapping Scan Total Station GPS-RTK From Others Utilities Data Sources Action ProcessAdjust Balance Import Check Import Register Clean Extract Check Field Edit Check Field Edit Rectify Plot Plot Analyze Archive Prepare for CAD
  • Data Collection, Analysis & Archiving-- Workflow From this point forward I will focus on the CADMapping process to create the final product Direct Process (for another session) Depth From Others Client Total Station Deeds & Maps Utilities Others Aerial Mapping Scan GPS RTK Final Product
  • Outline The Pitfalls of Diverse Data Data Round Up Examples Data Management During Drafting Data Collection, Analysis & Archiving Not all data is created equal
  • Pitfalls of Diverse Data More ‘hazards’ lie in combining this data Data is familiar, but the quality is not apparent Good quality “looks” the same as poor quality Point data is overwhelming -- extracted points are too exact; e.g. can’t tell what type of MH it is. Elevations are suspect. All data is remotely collected. Provenance of data is unclear Quality and breadth is unclear. Lots of non-survey info. Deeds, maps & images: lots of non-survey data. Deeds & Maps Utilities Others Aerial Mapping Scan GPS RTK Total Station Final Product
  • Outline Data Management During Drafting Data Round Up Examples The Pitfalls of Diverse Data Data Collection, Analysis & Archiving Background & Review Our Process
  • Typical Solution Process Foresight, leadership, and decisiveness. Deliberation and clear implementation. Followed by
  • Mercator’s Data Management Process Given: 1) All data is not created equal . . . 2) Not everyone may know that there are differences (or care). 3) Typical heavy workload makes good communication unlikely When viewed in CAD, the difference among data (namely points) should be self evident Workflow Visuals The result: Showing what we find in a clear and easily understandable manner Critical Point: Two Methods Governing Data Management
  • Framework -- Tools When looking for ways to manage the mess, I try to remember a lesson that I have a hard time following: K I S S For inside the office process, I look to existing tools: Field Codes Layers xreferences Nothing new. However . . . a wish: Easy metadata software to manage our survey data (quality, source, etc.) Point Groups File Folders Thumbnail Viewers Point Cloud Viewers For Clients:
  • Management – Collected Data Codes are applied Points are given a style Points are grouped Points are modified as they are imported into the CAD environment Typical workflow after we process points Software modifies the point description, moves points into a layer & inserts a symbol with a point. For direct points, staff sets a large node and uses vivid colors. For indirect points, staff sets a small node and uses subdued colors. Software groups the points by date and by type (e.g. scan or RTK)
  • Management -- Collected Data Control (GPS-Static, Traverse & Gyro) Deeds, Map & Images Aerial Mapping Scan Total Station GPS-RTK Others Utilities W -- Create Report V -- Lock points in CAD Generally not submitted & only referenced during CAD Similar in their limitations A separate category W - Workflow V – Visual Similar in their limitations A separate category Crucial framework data, but control is not used much in the drafting process These are a surveyor’s primary measurements.
  • Management – Collected Data Total Station GPS-RTK W -- use codes & many layers V -- Text EL60; Point node shown with a size respective to scale Workflow and appearance are conventionally the same “ Vf” for Survey - Field W -- use same codes but with an ”R” prefix V -- shown as regular points Reflectorless Workflow and appearance are the same. Points are in a different layer “ Vd” for Survey-Digital W -- use same codes V – shown as regular points W -- Points are exported with a PNEZDQ format. Points w/unacceptable or poor quality have a the text ‘NGCQ’ added to the code. V – shown as regular points Workflow and appearance are the same, but quality needs to monitored and noted. “ Vf” for Survey - Field Quality W - Workflow V – Visual Workflow and appearance are the same, poor quality is flagged “ Vf” for Survey - Field
  • Management – Collected Data Scan -- High-Definition Survey Extracted Points W -- points are exported with “R” codes. V -- Text & Node shown at ¼ size; colors are subdued Workflow is similar. Appearance makes drafting easier and clarifies the type of data. “ Vd” for Survey - Digital Entities Workflow is different and still evolving. “ Vd” for Survey - Digital W - Workflow V – Visual W – Draw and then export for point cloud software. Store in a “recycle” directory. Insert into CAD and modify. V -- color and layer are created by point-cloud software and then renamed in CAD once the entity has been reviewed.
  • Management – Collected Data Codes are applied Points are given a style Points are grouped Points are modified as they are imported into the CAD environment Typical workflow after we process points Software modifies the point description, moves points into a layer & inserts a symbol with a point. For direct points, staff sets a large node and uses vivid colors. For indirect points, staff sets a small node and uses subdued colors. Software groups points by date and by type (e.g. scan or RTK) Simple tools to organize data -- makes the origin and nature of the points self-evident.
  • Management – Data from Others Data from Others Aerial Mapping W -- Keep aerial mapping in its own drawing and use as an xreference. Field edits go into a new drawing. Staff moves revised items into a redundant layer that does not plot. ‘ <<layer name >>-R’ V -- use our line types & line weights. Redundant layer is visible but shown with a dark brown color to signify that it has been changed. Workflow keeps the aerial mapping as a separate drawing. Modified items are not deleted, but are shown with a subdued color Adjacent Survey GIS Orthophotography W -- Keep other work in its own drawing and use an xreference. Use XCLIP to hide areas not needed. V -- change colors and line types through the xreference, as needed. Workflow keeps the data by others in a separate file. Appearance can be changed without changing the original Other disciplines
  • Management – Records Deeds, Map & Images Utilities W -- Keep scanned document and analysis in its own drawing. It is not shared with the client. Export only lines that are needed and have been reviewed. Insert these lines into a new drawing. V -- change colors and line types as needed Workflow keeps the documents and analysis internal. Only the work that has been reviewed is prepared and provided to the client Appearance follows a company (or other) standard. All line work is drawn on a “ Vd” layer Survey-Digital
  • Management – Depth What does depth mean? What surveyors collect often has value to the client and allied professionals that is outside of a surveyor’s perspective. Don’t forget about it; share it. A plan-view survey is limited in showing additional information (the depth) to the client. . . . Our primary function as surveyors is to show what we find. And to organize it and make it understandable!
  • Management – Depth Point Clouds Utility Records Deeds, Map & Images Provide clients with a point cloud viewer or provide segment of the point clouds Provide clients with digital image of all records Add a references to collected documents Provide clients with digital image of all records Create thumbnail galleries Data Sources That Have Depth How to Show Depth
  • Outline Data Round Up Examples Pitfalls of Diverse Data Data Management During Drafting Data Collection, Analysis & Archiving
  • Layers and Codes Use a Robust Layering Scheme Use an existing framework such as: Discipline-Major-Minor-Item-Entity V is the discipline for Survey Vf = for direct measurement Vd = digital and non-direct Va = aerial mapping Major – Road, Util, Site, etc. Minor – Curb, Gas, Ground, etc. Desc – MH, Valve, Depressed curb Entities G- Geometry (lines, circle, etc.) S – Symbols T – Text & annotation H – Hatching P – Points R – Redundant Data
  • Examples -- Layers
  • Examples -- Codes
  • Appearance of Points This is our standard format and common to most firms When combining conventional and scan points, the screen gets too cluttered and becomes unclear. We import scan points with a different style than conventional points. I prefer an absolute size. A relative size can also be used
  • Scan Points in AutoCAD
  • Point Groups Point Group is a simple tool customarily used to put together similar points (e.g. trav, check & existing ground). It’s good practice to create a group for each day that survey work is imported. That is a date group. Additionally, we add a designation to the date group name: such as ‘RTK’ and ‘scan’ points.
  • Points -- Quality Using GPS in RTK is a fantastic productivity tool. Quality must be monitored continually. As points are collected good and poor quality points are generated. Sometimes you can use the good, the bad and the ugly (e.g. wetlands). Most times you can’t. When the ugly is used in combination with others, how should the CAD user be alerted to the nature of the points? Add ‘NGCQ’ in the notes during the field collection. Check quality when exporting from GPS software
  • Points -- Quality
  • Files from Others When we use files that were generated by others (namely aerial mapping), I like to keep the file in its original and unchanged state. Revised entities are moved to a redundant layer. The layer has a subdued color. Our additions are in a separate CAD file that is xreferenced along with the original aerial mapping drawing. The redundant layer is non-plottable.
  • Xreferences
  • Depth: Digital Documents In the digital age, many of the files we collect can now be easily shared. (and should be!) We organize the files so that the client (and our team) can readily find data. We also create thumbnail galleries for the client. This makes navigation and finding important images intuitive and easier.
  • Depth: Point Clouds 3-D scanning is a good tool to remotely collect a fantastic amount of data. The software for manipulating point clouds is expensive and hard to use. The database is enormous and has little meaning in plan view. Are there other formats? The viewer has limited functionality, but gives the client a way to access the data. and to answer questions for themselves! Animations are cool & sexy. Other than the gee-whiz factor, there is nothing substantive for the client. One option is to provide the client with a viewer to access the scan. However, almost of all of it is discarded and not used for the client.
  • Conclusion Codes Layers xreference Digital Deliverables Point Groups Here’s the concluding point: Show what you find: the good, the bad and the ugly. Tools If we don’t: We are missing our rightful place in the information age: .
  • Thank You Lem Morrison [email_address] 646 837 0780