geolink v6.4 for digital aerial sketchmapping · 2012. 4. 25. · geolink v6.4 for dasm (25 april...

US FOREST SERVICE

GeoLink v6.4 for Digital Aerial SketchMapping

A tutorial on using GeoLink v6.4 (Michael Baker Jr, Inc.) for forest health aerial survey data collection.

Authors: Charlie Schrader-Patton, with input from the community of forest health aerial survey specialists

4/25/2012

GeoLink v6.4 for DASM (25 April 2012) Page 1

Table of Contents

1 OBTAINING THE SOFTWARE ........................................................................................................ 2

2 INSTALLATION ............................................................................................................................... 2

2.1 Licensing GeoLink ...................................................................................................................................... 4

3 CREATE A GEOLINK PROJECT .................................................................................................... 5

4 CONFIGURE THE GEOLINK PROJECT ....................................................................................... 7

4.1 Enable Software Modifications ................................................................................................................. 7

4.2 Open Configuration Utility ........................................................................................................................ 8

4.3 GPS Settings .............................................................................................................................................. 9

4.4 View Serial Data ...................................................................................................................................... 10

4.5 Feature Setup .......................................................................................................................................... 11

4.6 Display Settings ....................................................................................................................................... 18

4.7 Preferences ............................................................................................................................................. 28

4.8 Background Maps ................................................................................................................................... 28

4.9 Simulate logging session – without GPS file. ........................................................................................... 33

4.10 Simulate Logging Session – with GPS file. ................................................................................................ 37

5 LOGGING DATA ............................................................................................................................. 39

6 EDITING DATA .............................................................................................................................. 39

7 DATA TRANSLATION .................................................................................................................. 47

8 APPENDIX ....................................................................................................................................... 48

8.1 DASM Metadata Attributes ..................................................................................................................... 48


8.2 LIMITS SHAPEFILE ALARM ....................................................................................................................... 51

8.3 CUSTOMIZING TOOLBARS ....................................................................................................................... 53

8.4 GeoLink / DASM Troubleshooting Notes ................................................................................................. 56

8.5 MULTIPLE MAPPERS: NETWORKING SURVEY PCS.................................................................................... 62

GeoLink for Windows is a highly graphical, user-customizable, data collection tool which utilizes GPS and

GIS technologies to georeference feature and/or sensor data. It can output collected data to several

GIS/CAD/text formats and can display a variety of GIS/CAD/Image formats as background maps. Other

capabilities include the ability for sketch lines, points, and polygons to be drawn and automatically

georeferenced onscreen, and the capability to input and output in many different user-selectable

coordinate systems.

GeoLink has been specially modified for use with aerial sketch mapping. These modifications allow

faster data entry, expanded onscreen sketching capabilities, and other functions, which make operation

easier, faster and more user-friendly. This tutorial document includes information pertaining to the

specific setup and operational procedures required for sketch mapping data collection. Regular aspects

of GeoLink are documented in the GeoLink User Manual.

GEOLINK CONTINUES TO SUFFER FROM STABILITY ISSUES (I.E. IT CRASHES OCCASIONALLY) DURING PROJECT

SET-UP. SAVE EARLY! SAVE OFTEN!

1 OBTAINING THE SOFTWARE Download GeoLink v 6.4 from here: http://www.fs.fed.us/foresthealth/technology/dasm

2 INSTALLATION Remove any previous versions of GeoLink (Add/Remove software in the control panel) Launch the setup exe. Assume the default program features to install:

http://www.fs.fed.us/foresthealth/technology/dasm


Sentinel Drivers must be installed for the software to be licensed; they are installed

separately from GeoLink:

Your PC may already have the drivers installed (other software programs use the drivers); if

so you may see this box:


The newer version should work fine so just click ‘Finish’.

2.1 Licensing GeoLink GeoLink is licensed by an unlock code that is derived from a serial number on the PC hard drive. When

you have received purchase confirmation of a license, go to ‘Setup’ ‘Software Protection’

’UpGrade Computer ID Key’:

Call Michael Baker Jr, Inc. and they will ask you for the Serial Number displayed in the

dialog. They will give you an upgrade code that will license the software.


When you want to transfer a license from one PC to another, get the Serial Number

from the dialog from both PCs and contact Michael Baker Jr Inc. to arrange the transfer.

3 CREATE A GEOLINK PROJECT When you open GeoLink for the first time (or after an install) it will prompt for a new project. You

can cancel and select a pre-existing project, or create a new project. If you are using a PC without a

GeoLink license to set up your project, you may get this warning:

This is okay, as we do not need to log data to set up our project.

Many settings in GeoLink will be the same for your particular survey area of interest (Projections,

Map groups, etc.), so you might create a “Template” project that you can open, add the maps of

the survey area, and ‘Save As’ to a specific filename.

GeoLink uses project files to store setup information. Setup information includes items

such as screen colors, background maps, coordinate systems, and database setup.

GeoLink projects consist of three files in the same directory, which have .def, .prj, and

.reg file extensions. A sample project called "USFS" has been created which contains

necessary configuration settings for use with aerial sketch mapping.

Assuming GeoLink was installed in the default "GeoLink" directory (C:\GeoLink), the project will be

located in the GeoLink\Samples\USFS\ subdirectory. The USFS directory may be moved or copied

to another location if desired. The project should not be copied to a path containing special

characters or spaces. The first time GeoLink is run, the operator must open the "USFS.prj" project

file. To open the project, select the ‘Project’-->’Open’ menu item. Using the browser, find the file

name “USFS.prj” inside the \USFS\ directory, and select it. This procedure must only be done the

first time GeoLink is run. After the first time, GeoLink will automatically open the last active

project.

In this tutorial, we will create the project “C:\FHP_ADS_GeoLink\Michigan\Lansing”. GeoLink

creates a folder for the project (Lansing), and a series of files that make up the project:


When moving projects from one PC to another, it is important to maintain the directory structure.

For example, if we built this project on our desktop PC and transferred it to a tablet PC, we would

build the directory C:\FHP_ADS_GeoLink\Michigan\Lansing on the tablet PC.


4 CONFIGURE THE GEOLINK PROJECT

Now we have our project created (Lansing). The main GeoLink document window should look

something like this:

GeoLink uses what is called a Multi-Document Interface (MDI), which means that within the

application there can be multiple documents (basically windows) which perform different functions

(log data, translate, view/print maps, etc.).

4.1 Enable Software Modifications To configure GeoLink for Aerial Survey, we first need to make sure that the necessary

modifications are enabled in the software. Go to the ‘Project’ menu item and select ‘Special

Customizations’. The ‘Aerial SketchMapping’ radio button should be selected:


4.2 Open Configuration Utility

Next, we will configure GeoLink by using the Configuration Utility. Many items in the utility

address functionality that does not pertain to aerial survey so we will leave those alone (e.g.

External Tables, Laser RangeFInder, DMI Device, and most of the settings under Session), so if a

setting item is not mentioned, assume the default values are adequate. Go to ‘Setup

‘Device’ ->’GPS’ and the Configuration Dialog will open:


We will work down the list on the left in the dialog, starting first with ‘Device’ ‘GPS\XDS\TRK’.

Select the ‘GPS’ button to bring up the GPS Settings Dialog.

4.3 GPS Settings


In the ‘GPS Receiver’ pick list you will select the type of GPS that will be used. Rather than

selecting a receiver, what you are doing is selecting a data type that is output by a receiver.

NMEA is a standard data type that many receivers can output. Virtually all the wireless

Bluetooth and built-in GPS units being used today support this format. We will select NMEA

for the GPS format.

The communication port needs to be set to the port that the GPS signal is piping data to; this

will vary depending on the devices attached to your PC and the firmware used to connect to

the GPS (Bluetooth, etc.).

Once the port is selected, there will be some settings on the right (baud, parity, data and stop

bits). For NMEA, the proper values are shown above (4800, None, 8, 1).

4.4 View Serial Data

Skip down to the ‘View Serial Data’ menu item under the ‘Device’ heading. This is a very handy

tool to check the GPS data coming in to GeoLink. The data from the GPS will be piped to the

window. If all settings are correct, the NMEA data will look likes something this:

Common issues with GPS data input include improper baud rate settings, wrong data input

type, and wrong COM port selected. If the baud setting is wrong, the characters in the ‘View


Serial Port’ window are usually a jumbled of strange characters, rather than the ordered,

comma-separated values of a NMEA string. If you get no data at all in the window, chances are

that the wrong serial port was specified. Try a different port and verify the port the GPS is

using in the Bluetooth Utility.

4.5 Feature Setup

Move down to the ‘Features’ setup item, which contains two sub-items, ‘Tables’ and

‘Definitions’. Most of the settings here are already done for us, but it’s useful to go over the

dialogs. In GeoLink, features can be thought of as having two parts – the geometry (point, line,

polygon) and the attributes (field values associated with the geometry).

The ‘Tables’ dialog defines the tables (field names and specifications); we are using a pre-

defined table called ‘Code_Definition’ to create the attributes for our features. No need to

mess with this table.

The ‘METADATA_START’ and ‘METADATA_END’ tables are used to define the fields for

metadata. These attributes are collected at the start and end of a logging session and are

explained in detail in the appendix. Setting up these tables will facilitate the quick recording of

these attributes. Since we are using pen tablet PC’s, entering text would be cumbersome so we

will use pick lists and default values in the metadata attributes. Here are the metadata dialogs:


You will be asked for two parameters at the start of a logging session – your name and the

survey type. If you have a dedicated tablet PC for your use, then it would be best to have your

name as the default, but also a pick list of a few others that might use the tablet on occasion.

Here is how to set that up. First, highlight the ‘METADATA_START’ table and on the right go to

the ’Properties’ button adjacent to the SURVEYOR attribute:


Click the ‘Properties’ button and in this dialog you will see numerous options and settings for

this attribute:


The important ones are the ‘Default Value’ where you will enter your user name. Since two

other users – rmech and mroberts - might also use this unit, we will set ‘Extended Type’ to

“Picklist”. This is a pull-down menu in a text box. The values in our pick list can be set by

clicking the ‘Editor’ button:


Pick lists are simple text files that can be edited in text editor like NotePad and transferred from

project to project.

Review the metadata attributes in the appendix and using the methods described above, set up

pick lists and default values for both the METADATA_START and METADATA_END attributes

using the methods described above. The REV_DATE and DATA_SOURCE attributes in the

METADATA_START table are auto-populated and do not appear in the dialog.

Most of the variables are already set up with domains (list of valid values) that are defined in

the FHM GIS Handbook

(http://www.fs.fed.us/foresthealth/technology/pdfs/GISHandbook_body_apndxA-C.pdf)

or in metadata definitions defined by the USFS Geospatial Advisory Council. The metadata

fields will be added to each feature collected during logging.

http://www.fs.fed.us/foresthealth/technology/pdfs/GISHandbook_body_apndxA-C.pdf


The ‘Definitions’ dialog allows us to set up the feature names, which are also the names of the

output shapefiles, the table used to create the features (in our case, ‘Code_Definition’).

The ‘Definitions’ dialog contains two important setting sub-dialogs: ‘Sketch Map Settings’ and

‘Symbols’. Select the feature definition in the left panel then click the ‘Sketch Map Settings’

button. The resulting dialog has three functions enabled:


‘Display’ provides setting options for how the features are displayed on the map, ‘Attribute

display’ contains some options for displaying attributes for the features as labels, and ‘Zoom

limits’ which allows us to control the map scale at which the features are displayed.

Clicking the ‘Symbols’ button in the ‘Definitions’ dialog activates a dialog for setting the symbol

that appears on the map for the feature. This is mostly relevant to point features; the symbol

for lines and polygons is displayed at the start point (first vertex digitized) of the feature. You

can turn symbols off in the ‘Sketch Map Settings’ dialog as well.


On the right side of the dialog are some important parameters for attribute text display. Select

a color and size that complement the background map colors, and utilize the zoom limits so the

display doesn’t become cluttered with label text at small scales.

IMPORTANT NOTE: These settings can only be changed when not logging data.

4.6 Display Settings

The ‘Display’ setup item contains dialogs that allow us to change the way the GPS track appears

on the map, zoom scale settings for the map, and the virtual keypad which we use to attribute

features. First, let’s look at the ‘Screen’ dialog:


4.6.1 Screen Settings

The dialog is divided into sections that set the GPS track and cursor appearance, the scale levels

used when zooming in and out on the map, and the background map color.

4.6.1.1 Cursor

This is the icon that represents the GPS position on the map. Use whatever you like,

the airplane is quite popular. Click the ‘Change’ button to bring up the icon

selection dialog:


This dialog has a ‘Heading’ slider bar that adjusts the icons orientation relative to

direction of travel. Set this so the icon is pointing up, unless you like to see the plane

icon flying sideways.

Next click the ‘Recenter’ button. GeoLink can recenter (refresh) the map screen in

three different ways.

The ‘Rotate’ option causes the background maps to be rotated according to the

direction of the GPS cursor. For example, if the aircraft turns and flies off the right

side of the map display, when the screen refreshes, the map display will rotate so the

GPS cursor is flying up the screen instead of left to right across the screen.


This is a very useful setting for aerial sketch mapping because it helps ensure that

objects on the right side of the aircraft correspond to the area of the screen to the

right of the GPS cursor.

If ‘Recenter’ is set to ‘Normal’, the map view will not rotate. Instead, the top of the

screen always corresponds to true north. If ‘Recenter’ is set to ‘Smart’, GeoLink tries

to minimize the number of screen refreshes by positioning the cursor in the most

logical location when refreshing. For example, if the GPS cursor goes off the right

side of the map view, the cursor will be repositioned at the left side of the map view.

If the cursor goes off the bottom-right corner of the map view, it will be repositioned

to the top-left corner of the map view.

The ‘Screen Location’ grid allows us to select the location of the GPS cursor when the

display refreshes. Thus a position on the left side of the grid as shown above would

be optimal for an observer sitting on the right side of the plane. While the GPS

cursor “flys” up the left side of the screen, the observer has a good view of the map

area that is visible out the right side of the aircraft. The ‘Recenter Border Width’ is a

relative value that determines how close the GPS cursor can come to the edge of the

map display before the screen is automatically refreshed. A setting of 100 is a

typically good for aerial survey.

The ‘GPS Track’ section controls the color and size of the GPS track “cookie crumbs”

that appear on the map display.

‘Map Width’ defines the width in map units that will be displayed when the map is

initially opened. We will start with a value of 8 miles. The ‘Scale Levels’ button opens

the following dialog:


In this dialog we can enter the scale increments that will be used when the zoom

in/out tools are used. We will add the following values to create the scale list:

Click the ‘Use the scale list’ checkbox to enable the scale list with the zoom tools.


‘One Touch Zoom’ is a special tool in the map that allows you to zoom with one click

to a particular scale. It was developed so that if, during a survey, you want to zoom

out to get a quick overview of the map you can do so with clicking the regular zoom

tool multiple times. Set the desired map width to zoom to when the tool is clicked in

the ‘One Touch Zoom’ section.

4.6.1.2 Virtual Keypads

Virtual keys are the buttons that we will use to attribute our features. They are

buttons that correspond to any string of characters that we define. Typically

forest health surveyors have keys that represent damage agent codes and ones

with digits 0-9 to specify the number of trees affected or trees per acre. Keys

are grouped into keypads, so we can have keypads for specific areas or surveys.

Using the dialog, we will define some keypads for use in our project. Setting a unique color

for each keypad makes the keys easy to pick out during data collection. Checkboxes allow us

to view only one keypad at a time, and to set a default key that gets applied to every feature.

Here is the dialog with our keypads:


The keypads that have been checked will appear in toolbar to the right of the map when

logging. When a keypad is selected for a feature, the string of characters associated with

that keypad is appended to the ‘Code’ field for the feature.

4.6.2 Translation

GeoLink collects data as a group of files called proto-shapefiles; these data will need to be

output to a usable GIS format and additionally referenced to a coordinate system. This

process is called Translation and a number of settings can affect the output data. A copy is

made of the data – the original logged data are not modified – thus the same log data can

be translated many times.

The ‘Input/Output’ pull-down list should be set to the GPS file type used in the log data

that you want to translate – in our example, we will use NMEA. Set the Target GIS file type

to ‘ArcView Shapefile’. Make sure that ‘3D Output and ‘Recalculate are NOT checked.


4.6.2.1 Auto merge polygons

GeoLink’s translate utility can detect polygons with the same “Code” attribute

that overlap and merge them into one polygon (‘Auto merge polygons’ check

box). Only polygons with identical attributes in the “Code” field will be merged.

Auto merge is analogous to the Dissolve function in ArcMap. If the checkbox is

not checked, all polygons will be output as individual units and any joining

polygons will need to be edited in the GIS. For proper performance of the merge

function, a text attribute with the name “Code” (case insensitive) should be

defined in the Table Definition. The default table definition for aerial survey

(Code Definition) contains the properly formatted Code field.

4.6.2.2 Union of overlapping polygons

When this checkbox is checked, the translate utility will create unique polygons

out of the overlap areas between two polygons. This is analogous to the Union

utility in SketchTools.

NOTE: The union function can have unpredictable results if two or more

polygons overlap a single polygon, or if there are inclusion polygons within

larger polygons. Check the results carefully. Also, the overlap area is not

removed from the two parent polygons. If your log file contains these types of


polygons, you may consider translating without the ‘Union overlapping

polygons’ box checked and using the Dissect function in SketchTools.

4.6.2.3 Conversion of multi-part features to single part features

ESRI Shapefiles support multi-part features – in other words, a single record in

the table can represent multiple ‘features’. This is advantageous for aerial

survey because you can sketch in multiple lines, points, or polygons and if they

all have the same attribute, just key in the attribute and press ’Enter’. When this

file is translated into a shapefile, you will notice the groups of features that you

entered will only have one record in the database. This can pose problems if you

want to conduct post-processing functions such as calculate acres, create

polygon centroids, etc. GeoLink contains functionality to convert these multi-

part shapes to single part shapes during the translate process. Selecting the

checkboxes in the Translation Setup (Target GIS) will result in the output feature

shapefile containing single part shapes rather than multipart shapes.

4.6.2.4 Creation of a Garmin Waypoint+ file

When points or multi-points are collected, you may want to output those points

to a Waypoint+ file that can be directly loaded into a Garmin GPS receiver so

that field crews can navigate directly to the points for ground verification. In the

Target GIS dialog, check the ‘Waypoint+’ box and a text file will be created in the

Translate folder. This file will be named in the format “wpy_hhmmss.txt” where

hh, mm, and ss stand for “hour,” “minute,” and “second” (time of translation,

not data collection) respectively. Waypoint+ files require a unique identifier for

each point, so you will be prompted for a starting value for this unique

identifier.

If you have multiple waypoint files to upload to a Garmin GPS, you can select

the starting points appropriately so that the points are not overwritten during

the upload process. For example, let’s say you have two point files that you

want to upload. The first file contains five points, and the second contains ten

points. Set the starting value for the first file as ‘0’ and the second for ‘5’. Now


you can upload both files to the GPS and you will have all 15 waypoints loaded

into the GPS. There are many freeware or shareware programs available that

will upload Waypoint+ files – MN DNR Garmin, OziExplorer, and WayPoint+.

4.6.2.5 Output polygon centroids as points

Selecting this checkbox will produce a point shapefile of the polygon feature

centroids with the polygon attributes. This can be useful for loading polygon

locations into a GPS unit.

4.6.2.6 GPS Fixes

Click the ‘GPS Fixes’ button and this dialog comes up:

The only setting to check here is ‘Output GPS fixes As’. When data are translated,

GeoLink can create a point or line shapefile from the GPS points. Check the box

next to the feature type desired.

4.6.2.7 Coordinate System

During the translation process, data are projected into the coordinate system

displayed in the ‘Coordinate System’ box on the ‘Target GIS’ dialog. To change

the output coordinate system, click the ‘Change Coordinate System’ button.


4.7 Preferences

The ‘Options’ dialog under the ‘Preferences’ item contains some settings that can save

keystrokes, such as the default map location path. ‘Disable Floating Toolbars’ should be

checked if you are inadvertently undock the toolbars.

4.8 Background Maps

GeoLink supports several different raster and vector geodata types for display as background

maps. Several enhancements improve display refresh performance, including SplitShape, a pre-

processing utility that applies a spatial index to large shapefiles, and SplitTiff which creates a

special pyramid raster file (.gor = GeoLink Optimized Raster) that displays quickly at all scales in

GeoLink. The ‘Map List’ dialog is the interface to add, order, group, and set the scale

dependency for our background map files.

For our project, we have added two map sets – Digital Raster Graphics (DRG) and imagery -

covering the central Michigan area. GeoLink Optimized Raster (.gor) files were created from

the original tiff and jpeg files. For more information on preparing raster data, see

http://www.fs.fed.us/foresthealth/technology/pdfs/DASM_Image_Map_Manual_2012.pdf.

Using a wildcard character (*) can be a handy way to add lots of maps. Organize your

background map files logically, for example by geographic area and type (imagery type, DRG,

etc.).


In our project we will create two map groups, one for the DRGS and one for the imagery. Map

groups let you combine multiple map raster files so that a surveyor can turn off/on groups of

maps with just one button click.

Click on the ‘Map Groups’ button. In the ‘Mapgroup Setup’ dialog we can create the two map

groups and assign the maps to each group. In our map list, we have added the nine DRG raster

files individually and the image files using a wildcard in the file name.

NOTE: Be sure that every background map file is assigned to a map group.


The ‘Map Description’ panel on the left in the ‘Map List’ dialog allows us to see the settings for

the selected map. To change these settings, click the ‘Settings’ button:

Some of the options in the ‘Map Settings’ dialog are for vector datasets and so are disabled if

the map selected is a raster. Define the coordinate system for the data; our DRGS are in NAD83

Zone 16.


IMPORTANT: You must assign the correct coordinate system to all your background map data.

Most background map errors are related to this.

Enabling scale dependency, or zoom limits, is a good way to manage multiple layers of

background map data.

Most of our map data are in a USGS map tile format, such as 30’x60’ 100,000 scale quads, or

1:2400 7.5’ quads. To create a seamless map, GeoLink can do a virtual crop along these

boundaries and eliminate any collar or “no data” areas along the map junctions. Select the

‘Cropping’ button:


Our maps are 30x60 quad tiles so entering the appropriate quad size and checking the box will

crop our maps.

Check the setup of the background maps by clicking on ‘View/Print Maps’. The maps should

appear in their full extent. Test the Map Groups buttons (DRG, Imagery in our project):


4.9 Simulate logging session – without GPS file.

The best way to review all the settings in our project is to simulate a log session. This is a

powerful capability of GeoLink that allows us to check to see that our project is set up properly

– maps, keypads, default settings, etc. – before we get into the aircraft.

We can simulate a log session either by playing back a previously collected GPS file or without a

GPS file if none is available. A GPS file of the Lansing area was not available, so we will simulate

without a GPS. From the main GeoLink document, select ‘Process’ ‘Simulate’. Next select

‘Logging’ ‘Log without GPS’:

GeoLink now prompts us to pick a method to geolocate the logging session:


Select ‘Center on a background map’ pick one of the maps from our map list. The map selected

must be turned on (= checkbox checked).

Now the session has started and we see the GeoLink interface exactly as we will see it during a

logging session. Check to see that the virtual keypads and map group toolbars are visible.

In the figure above, some of the key parts of the logging document are identified. To collect a

feature, first go to the feature selection list at the bottom right. Select a feature type (area,

point, etc.). Now draw the feature on the map (the draw tool will automatically become

active). After you have finished drawing the feature, notice that there is now an ‘Enter’ button

at the bottom right that is flashing. This is to tell you that a feature geometry has been

Virtual Keypad

ToolBar

Map Groups

ToolBar

Virtual Keypad

Window

Feature Selection

Pick List Feature Attribute

Text Box


digitized and needs to be committed to the database. During an actual survey, the map display

would stop updating until the ‘Enter’ button was clicked.

Before we commit the feature, we need to give it some attributes. GeoLink collects attributes

in a single text field which is called “Code” in the output shapefiles. We will use the virtual

keypads to build the text in the feature attribute text box that will be assigned to the feature.

Clicking on the ‘ALB;’ and then the ‘1-5’ virtual keys populates the text box with ALB;1-5:

Now click the ‘Enter’ button and the feature with attributes has been collected:


When we first draw the area (polygon) features on the screen, they appear solid green. If we

want to change that symbology, click on the sketch settings button. Here’s what it looks like:

Clicking on this tool will bring up a dialog that allows us to change some of the characteristics of

sketched geometries before they are committed to the database:


4.10 Simulate Logging Session – with GPS file.

If we have a GPS file for our project area, we can play the file back and simulate the screen

refresh settings for our project. The procedure for collecting features is the same as when

simulating without a GPS file (see above).

From the main GeoLink document, select ‘Process’ ‘Simulate’. Next select ‘Logging’ ‘Log

with GPS’. A dialog asking us to select the GPS file (*.dat for NMEA files) appears:


After selecting the file an application called ‘GeoLink GPS Server’ will open:

This application is necessary to deliver the GPS positions from the COM port to the map, so be

sure not to close it, just minimize it to the Windows task bar.

These GPS files are critical for translating data and are saved with every log session; they can

easily be copied and used simulations.


Simulating with a GPS flight file enables us to test screen refresh settings such as recenter

position, border width, and method. It also allows us to become very familiar with data

collection workflows in a desktop environment, maximizing efficiency when in the aircraft.

5 LOGGING DATA Collecting data is very similar in work flow to simulating as described above in Section 5.10, except that

instead of selecting ‘Process’ ‘Simulate’ we will select ‘Process’ ‘Log’. If GeoLink is not licensed,

the ‘Log’ menu item will be grayed out.

6 EDITING DATA Feature geometries and attributes can be edited during a log session. To enter the edit mode, double

click on a feature on the map and the selected feature will flash on/off. Also you will know that you are

in edit mode because the edit tools will appear at the bottom of the map:


If we have selected a polygon, then the ‘Expand Poly’, ‘Truncate Poly’, and ‘Append Poly’ tools

will be available along with ‘Delete’ and ‘Edit Attribute’.

Clicking the ‘Edit Attribute’ button brings the features attributes (“Code” value) up in the text

window. You can use the virtual key pads, Backspace, Copy and Clear buttons to change the

attribute text.

‘Expand Poly’ enables you to digitize an area that overlaps the current polygon; the polygon

will be expanded to the new digitized area:


In the above screen shot, the expansion area for the polygon has been digitized. Next hit the ‘Enter’ key

and the expansion area has been incorporated into the polygon:


The ‘Truncate Poly’ tool allows us to essentially take a bite out of a polygon. Sketch in the area that you

wish to be reduced from the polygon:


Click the ‘Enter’ key and the overlap area is removed from the polygon:


The ‘Append Polygon’ tool allows us to create a new polygon that shares a boundary with the current

polygon. This tool can be handy to avoid small slivers between adjacent polygons. Click on the ‘Append

Poly’ tool and digitize an area that overlaps with the current polygon. Then enter in the attributes that

you want to assign to the new polygon. In the example below we are coding the appended polygon

‘FIRE’:


Click the ‘Enter’ button and we now have a new polygon that shares a boundary with the original

polygon:


When we select a feature to edit, the screen will lock (i.e. will not update based on current gps

position). When the feature is committed to disk (‘Enter’ button), then the screen will refresh to the

current position. To add or edit features that are beyond the current extent of the map display, use

the pan tool. While in the ‘Pan’ mode the map display will not refresh to current location. We can

then pan to the area where we want to add/edit features and use the ‘Sketch in Pan Mode’ to edit

or add feature. The tool looks like this:

Using the Pan tool, we can edit and clean up our features after the survey grid has been completed

while in transit back to the airfield. Be sure to practice with the edit tools in simulated log sessions

so you are familiar when it comes time to fly.


7 DATA TRANSLATION The Translate mode is used to convert GeoLink’s proto-shapefiles collected during a log session into

GIS compatible shapefiles. During the Translate process, the shapefiles are projected into the

coordinate system you specified in the Target GIS‟ dialog box.

To translate your data, pick “Select Files” from the Translate menu, open the projects Log folder and

the day’s folder (DDMMYY) that the mission was flown. Now select the GPS (HHMMSS.dat) file in

the day’s folder, which is associated with the proto-shapefile data in the folder of the same

HHMMSS name which you wish to translate.

For example, to translate files from a January 2, 2003 Training.prj mission that began at 3:22:12 pm

local time, you would select: C:\sketchmap\Oregon\Training\Log\010203\152212.dat.

This would select both the 152212.dat GPS file and the proto-shapefiles located in the associated

152212 folder. The selected files will load and you will see a graphical representation of them on

screen.

Useful Tip: If you depress the <Ctrl> key while selecting multiple files, the collected data will be

appended together in your output shapefiles. To append and translate multiple files, all files must

be in the same Log directory. The input file(s) will display immediately after you select them.

To complete the translation, select “Translate selected files”

The shapefiles will be written to the appropriate date/time folder in the project’s Translate folder.

The date and time files and folders created here reflect the date and time of the translation, not the

original aerial SketchMapping mission.

A text file is created and displayed on screen showing how many features were collected and how

many were translated. This file is named after the start time of the translate operation and is stored

in the appropriately-named date and time folder. Contact support staff if all features were not

translated.

NOTE: The two-step Translate process explained above runs very quickly. You should have the

time to translate the day’s proto-shapefiles while ferrying back to the airport. It is recommended

that you run the translation during the same day, since you can see the results while the mission is

still fresh in your memory, and your logged data folder and translated data folders will be named

for the same day.


8 APPENDIX

8.1 DASM Metadata Attributes

The following metadata items are proposed additions to the ADS data files. The metadata will be

recorded with each feature so they remain as a permanent record throughout any GIS processing or

analysis.

The purpose of these metadata is to assist end-users of ADS data in determining the utility of the aerial

survey data for a specific analysis or mapping process.

Within the GeoLink software structure, there are two opportunities to collect metadata attributes:

Pre-Survey – When the user starts a logging session

Post-Survey – When the logging session has been stopped, but before GeoLink is closed.

Pre-Survey Fields

Sketchmapper name Field Name: SURVEYOR Required: Yes Field Type: Text Field width: 8 Field Domain: N/A Description: This will be the first initial of the surveyors’ first name, followed by the first 7 characters of the surveyors’ last name. If there are less than 7 characters in the users last name, use all the characters. Examples Charlie Schrader = cschrade, Lowell Lewis = llewis. All characters lower case. No picklist. Users can enter default value in Setup function. Survey Type: Annual Overview, Special Field Name: TYPE Required: Yes Field Type: Text Field width: 8 Field Domain: annual, special Description: Users must select one of these two types. Picklist table selection (SURVEY_TYP.lst): Users can enter default value in Setup function, preferably by selecting a value from picklist table. Revision Date: Required Forest Service Metadata field showing date the feature was collected or most recently edited. Field Name: REV_DATE Required: Yes Field Type: Date Field width: (Format MM/DD/YYYY) Field domain: Date


Description: Date is automatically populated from GPS input at start of logging session. May be changed post-GeoLink by GIS analyst if the polygon is edited. Not seen by user. Ref: http://www.fs.fed.us/gac/metadata/feature_level.html Data Source: Required Forest Service Metadata field Field Name: DATA_SRC Required: Yes Field Type: Text Field width: 2 Field domain: 24 Description: Every feature collected in aerial survey is given the value “24”, which is the code for “Other”. Not seen by user. Ref: http://www.fs.fed.us/gac/metadata/feature_level.html

Post-Survey Fields Survey Pattern: Contour, Grid, Mix, Ground Field Name: PATTERN Required: Yes Field Type: Text Field width: 4 Field Domain: cont, grid, mix, grnd Description: This is the flight pattern of the aerial survey, or identified as ground for all non-aerial surveys. Picklist table selection (PATTERN.lst) Users can enter default value in Setup function, preferably by selecting a value from picklist table. Survey swath width: Survey recording distance Field Name: SWATH_DIST Required: Yes Field Type: Float Field width: 2, 2 Description: The distance from the aircraft position to the farthest extent the surveyor is observing. Based on single observer; i.e. if two surveyors are conducting a mission with each person mapping up to 1.5 miles from the aircraft position (Right side and left side of aircraft), then the value of this field would be 1.5 and not 3. Domain: Range .25 – 10, .25 mile intervals in statute miles Picklist table selection (Survey_Swath.lst): Users can enter default value in Setup function, preferably by selecting a value from picklist table. Surveyor viewing direction: Right, Left, Both Field Name: VIEW_DIRC Required: Yes Field Type: Text Field Width: 5 Description: Indicates direction from flightline being surveyed.

http://www.fs.fed.us/gac/metadata/feature_level.html

http://www.fs.fed.us/gac/metadata/feature_level.html


Domain: right, left, both Picklist table selection (VIEW_DIRC.lst): Users can enter default value in Setup function, preferably by selecting a value from picklist table. Survey conditions: Acceptable, Marginal Field Name: CONDITIONS Required: Yes Field Type: Text Field width: 4 Field domain: good, marg Description: This represents the surveyors’ assessment of the conditions (weather, visibility, sun angle, etc) relative to the type of damage being mapped. Picklist table selection (Survey_Condition.lst): Users can enter default value in Setup function, preferably by selecting a value from picklist table. Overall Survey Confidence: Acceptable, Marginal Field Name: CONFIDENCE Required: Yes Field Type: Text Field width: 4 Field domain: good, marg Description: This represents the surveyors’ assessment of his/her ability to accurately map the targeted

damage. Factors may include the conditions (above), the surveyors experience mapping this type of

damage, presence of confusing signatures that may cause either errors of commission or omission,

surveyor fatigue, etc.

Picklist table selection (Survey_Confidence.lst) Users can enter default value in Setup function,

preferably by selecting a value from picklist table.


8.2 LIMITS SHAPEFILE ALARM

The limits shapefile feature allows us to have an alarm/warning activated if we are entering or

leaving a geographic area. This could be used to avoid a military ops area, or to notify the surveyor

when they are approaching the boundary of a survey area.

The dialog box is a list of polygon shape files that have been entered in the backgroundmap list. The

operator may select one or more of these files as the limits shapefile. These files may contain one

or more polygons that define the limits of the allowable sketch area. Care should be taken to

simplify these shapes by eliminating lines and generalizing as much as possible. For each data point

the system must process each of these polygons and their lines.

The limits shapefile feature can operate in two ways. One, it will warn you when you are

approaching a polygon or polygons. For aerial survey, the polygon layer could represent TFRs

(Temporary Flight Restriction areas) where flying is prohibited. This is called external boundary

approach. The surveyor could set up the limits shapefile to display a warning when the plane is

within 2 miles of a TFR. Two, the limits shapefile feature can be used to warn a surveyor when they

are leaving a large polygon. This could be used if the survey is to cover a specific area, and the


surveyor wants to know when they are close to the boundary of the area. This is internal boundary

approach. The user controls whether the utility uses internal or external boundary approach by

selecting or checking the polygon shapefile in the limits shape dialog.

Selecting a polygon shapefile means it is highlighted. The surveyor will be warned when leaving a

polygon in a selected polygon shapefile. A checked polygon shapefile is one where the checkbox to

the left of the shapefile contains a check mark. The surveyor will be warned when approaching the

boundary of a checked shapefile. If a shapefile is both checked and selected, then the external

boundary approach will override the internal boundary approach.

The “Warning Distance” defines a virtual buffer zone that is placed around the selected boundary

polygons. Positive numbers will effectively expand the boundary around the polygon(s); in other

words, if you enter ‘1 mile’ as your warning distance, the alarm will sound when you are 1 mile

outside of the polygon boundary. Negative values will cause the boundary to shrink; entering ‘-1

mile’ will result in the alarm sounding when you are 1 mile inside the polygon boundary. The

“Warning time interval” is the interval between one warning and the next. If points are continuously

outside the limits, the sound will wait the specified time interval before emitting the sound again.

NOTE: During sketching, the warning will not sound until there is a slight pause in the movement of

the mouse.

The “Check Limits on GPS/Sketch” check boxes will turn on or off limit checking for GPS points and

Sketch features respectively. Checking the ‘GPS’ box will sound the alarm if the aircraft position is at

the limits set in the dialog; this setting is probably the most useful for aerial sketchmapping. Either

or both of the boxes may be checked. If neither box is checked, no limit checks will be performed.

The “Cancel” button will cancel the changes and leave the system the way it was before the dialog

box appeared, and also will stop the limits shape utility. If you are receiving alarm warnings and

want them to stop, click this button.

NOTE: The limits shapefile utility only works with shapefiles that are unprojected (Geographic).

Reproject any shapefiles that you may want to use as limits shapefiles to geographic and be sure to designate the coordinate system appropriately in the map list. Only use a polygon shapefile with a single polygon as a limits shapefile for internal boundary approach. If you use a file with more than one polygon, GeoLink will continuously interpret the position as being outside of the polygons, since the position is not in all polygons.


8.3 CUSTOMIZING TOOLBARS

The default toolbar settings in GeoLink may be adequate for your needs, but in many cases surveyors

want to customize the appearance of tools and tool bars in GeoLink. To do so, go to ‘View’

’Customize’. In the ‘Customize’ dialog’s toolbars tab, toolbars can be displayed or hidden. To have a

toolbar shown, place a checkmark next to the toolbar name.

In the menu tab, various menu animations can be selected other than the default “none”. New

animations include unfold, slide, and fade. In addition to changing the menu animations, a shadow may

be placed under the dropped down menu by placing a check next to ‘Menu shadows’.


The final tab is the ‘Options’ tab. This tab (shown below) has options to show tooltips under menus,

show shortcuts, and give GeoLink the look of Windows 2000. The option most used will be the Large

Icons to make the toolbar buttons easier to see and activate. This is also accessible through the GeoLink

menus.


To change the appearance (icon, text, or both) of a tool, right-click the button you want to tool, and

then click ‘Button Appearance’ on the shortcut menu. To display text, click the ‘Text Only’ button or the

‘Image and Text’ button. You can also change/add the text to display with the button. To display an

image, click Image Only or Image and Text, and click an image in the Images area.

Note: You cannot change the text and icon format for a button that displays a menu list when you

click it. When you display text on a toolbar button, the button does not display a ToolTip. Some

commands do not have an icon associated with them and can only be displayed on a menu as text. A

menu command cannot be displayed as an icon only.

To remove a tool from a toolbar, open the ‘Customize’ dialog and drag the tool off the toolbar.


8.4 GeoLink / DASM Troubleshooting Notes

D. Ryerson

5 July 2011

Boot Failure on HH (July 2009)

The original Hammerhead unit obtained from R2 had an in-flight failure early in the season. On

booting it would flash a blue screen error, then reboot, entering a repeating cycle. The fix was

to:

At the office, connect to USB hub with keyboard, mouse and external drive.

Boot to a Windows XP Professional CD.

Enter the XP recovery console, run chkdsk with the /f switch.

A bad sector, presumably containing a critical Windows file, was found on the hard drive and

repaired. This system problem was not observed again during the remainder of the season (nor

2010 or 2011).

Big Icon / Default Settings Project Error

History / Symptoms

This error was first particularly observed in 2008. The problem occurs after a project is created

and then opened at a later stage. When the project is opened:

The project will initially work properly when building. The problem is encountered after saving

and then re-entering GeoLink. The first symptom observed is the ‘Big Toolbars’ setting turned

being on.

Screen settings revered to a black background, arrow pointer, no GPS track display (see screen

capture below).

Map list is typically cleared.


Screen capture of GeoLink project with ‘Big icon /default settings’

Solution

Maintain current backups of all projects. When project exhibits this problem, exit and replace

with the good backup copy.

Process all shapefiles from ArcGIS through ArcView prior to including in any GeoLink project

(See next section. DR – this process seems to prevent a majority of the cases, but does not

seem foolproof).

Notes

A project with this error was sent to Charlie Schrader-Patton who was unable to replicate the

problem. Since only the project was sent and not the background map data, this seems to

confirm that the problem is tied to the data. Aaron Morris of Michael Baker Jr., Inc. provided

troubleshooting tips, but we were unable to solve the issue. One of Aaron’s final suggestions

was to build a project from scratch, not using any template as the basis

Logging Module Error

History / Symptoms

This error was first observed in 2011. The problem occurs when “Start Logging” is selected from

the main module.

Immediately the following error appears:


Upon selecting OK, this error appears and GeoLink exits to the main screen or quits completely.

Solution

Problem is due to duplicate feature types defined in the definitions. Example from problem

project shows double Area, Line, and Point features defined.

Deleting the duplicate feature types will allow logging (delete one each of the Area, Line, and

Point feature definitions).

As always, maintain current backups of all projects.


Notes

Charlie Schrader-Patton was able to diagnose the problem and provide a solution. It is unknown

why it occurred. Aaron Morris from Baker is looking into the problem to see why it occurs.

Initial thoughts are differences in GeoLink versions (possible use of 6.3; might be possible since

6.3 was loaded on a tablet last fall here for testing).

Problems with ArcGIS Shapefiles

History / Symptoms

Problems have been encountered when using ArcGIS-produced shapefiles in GeoLink. This issue

might also contribute to the ‘Big icon / default settings’ project error. Symptoms of this

problem include:

When processing shapefiles through SplitShape, the application will open and appear to

process shapefiles, but the multiple passes are not completed and no .slf file is created

GeoLink crashes while logging; once the failure starts, getting back into the project and starting

logging again typically results in an almost immediate crash. Removal of the problem

shapefile(s) (if known / recently added) will typically resolve the problem.

Attempts to solve the problem have included deleting the ‘extra’ shapefile components leaving

only the .dbf, .shp, .shx, and the .prj files. This allowed SplitShape to run through its passes (1,

2, 3...) and projects built fine and worked for awhile and then the errors started.

Solution

Bringing the shapefiles into ArcView 3.X and exporting to new shapefiles has been the overall

best solution. Given that I have encountered the problem several times, I run all shapefiles for

use in GeoLink through ArcView 3.X prior to adding to a GeoLink project and have

recommended to our other observers to do the same. Additionally I found it best that

shapefiles do not contain M or Z values which also appear to cause problems. These processes

also minimize the possibility of encountering the ‘Big Icon’ problem.

Lost Bluetooth Connectivity

History / Symptoms

Occasionally when starting up from shutdown, the Bluetooth connection to the GPS will be lost.

Solution


Depending upon the DASM in use (HH or Dell XT2 XFR), the solutions may vary slightly. On the

Dell, going into the Bluetooth places dialog box and clicking on the GPS may re-establish

connection.

For the Hammerheads (and if re-establishing a link by clicking on the GPS in the Dell does not

work), unpair the tablet and PC. Re-establish the pairing (using code 0183 on EMTACs, 0000 on

HOLUX). Once a messages that a COM port has been established, reboot. Do not go into the

Bluetooth settings after rebooting, go directly into GeoLink (or HyperTerminal if you want to

check connection before starting logging).

Notes

While the Bluetooth connection will often show the GPS as unconnected even when it was

previously paired and connected. It seems until an application starts communicating with the

GPS, it will show as unconnected. Trying to connect again through the Bluetooth menu when a

connection has already been made seems to create more problems and will not re-establish the

connection, requiring an unpairing and then re-establishing the pairing of the tablet and GPS.

Moral of the story, once a GPS is successfully connection, effectively ignore the Bluetooth

menus and just go directly into the application after startup.

Translation Errors

History / Symptoms

GeoLink may return an error when translating if the project does not have the same settings as

the ones the logging session was conducted in. This is particularly a problem when a log file is

translated at a later time using a different project / computer.

Solution

Make sure Feature types (MPoint, Area, Point, Line) match those of the file – if they are

different, GeoLink will return an error. Change the feature types to match or open a project

that has the same feature types and translate the file from that project.

Translation Error - EventID Error

History / Symptoms

When translating, GeoLink returns the following error:

"EventID X: Feature was collected after GPS ended. This feature cannot be output."

Solution (thanks to Charlie Schrader-Patton for the following write-up)


The EventID error usually occurs after a feature was deleted / edited during a log session, or

sometimes with a GPS hiccup. Try this:

Open up the mdb, and look at the event table. EventIDs are unique to a type of event -- such as

entering a polygon, point, line, or deleting a feature. I think deletion is 9.

Take note of which feature was deleted in the record with EventID 9.

Now delete this record in the event table, and go to the corresponding feature table and delete

the "deleted" feature. Now try a translate. Always do these tweaks to a copy, just in case.


8.5 MULTIPLE MAPPERS: NETWORKING SURVEY PCS

Bluetooth Networking DASM Unitsi

D.E. Ryerson ([email protected])

8 January 2010

Slight updates 2 March 2012

1. Enable Network Access on both units to be connected. Choose Bluetooth Configuration >

Local Services > Network Access. The following property dialog box will appear, turn on the Startup Automatically option and make sure the type of service is set to Allow other

devices to create a private network with this computer.

2. Share the log folder of interest on each tablet PC by selecting Properties > Sharing. Turn on the Share this folder on the network and give a Share Name. Suggested folder to share is the main log folder for the year / user.


3. Initiate the network connection by going to the Bluetooth Neighborhood. Choose the other tablet PC to be connected and double-click. In an office setting there may be multiple devices in range – Hammerhead XRT circled in this example.

4. The following services should be present on the tablet PC (more may be present if additional services have been activated).

5. Double-click the Network Access option. A dialog box asking for a security code will appear on each unit. Click on the dialog box and a security code request box will appear. Enter the same code into each unit – note the code is not preset-the user can enter any number as long as it is the same on both units.


6. A second dialog box will appear from the taskbar on the secondary tablet PC. Click on the dialog box and the following window will appear asking for authorization to complete the network connection. Click OK on this box to authorize the connection.

Note the Always allow this device to access this service option can be selected to prevent having to approve the connection each time.

7. The Bluetooth Network Access will change to the following:

8. Map the network drive on each machine using a drive letter that is unique.


9. After initially connecting, the GPS connection is sometimes lost. Go into the Bluetooth

Neighborhood > BTGPS > Bluetooth Serial Port on BTGPS. No code will be required as during an initial connection. A successful connection screen will appear.

10. After each reboot / shutdown, the network connection to the other tablet PC (not the GPS) will need to be refreshed by going into Bluetooth Neighborhood > XRT > Network Access

on one machine. If the Always allow this device to access this service was not selected above, then the authorization dialog box shown above will appear on the other tablet PC and OK will need to be clicked. If the Always allow option was selected, nothing needs to be done on the other tablet PC.

11. In GeoLink, start loggingii on both machines. In the Map List dialog box, select the log folder for the current day and add *.shp (note that the data subfolder, named with the time, will not be present until features are drawn).


12. Features drawn and entered on one unit will appear on the other unit as soon as the feature is attributed and “Enter” is clicked on the machine and the screen is refreshed on the corresponding machine. Since the shapefiles being displayed are GeoLink’s proto-shapefiles, there is no DBF containing the attribute values. Thus the display text function in GeoLink will not work on these shared files; only the geometry of the features is shared.iii

i These instructions are based on connecting two Hammerhead XRT units both using Belkin USB Bluetooth Adapters. The

specific references will change depending upon the model of the tablet/Bluetooth adapter.

ii The date folder for the current day will not be present in the log folder until logging is started in GeoLink or the folder has been

created manually.

iii While adding *.shp prevents attribute display, adding individual shapefiles does not fix the problem – there is no DBF file for

GeoLink to use. For example, if the individual Areas.shp is added after it appears on the networked machine and the Display att

button is selected, GeoLink returns the error “Unable to locate the database file” since no DBF is present. Additionally if the

Attribute-Based display option is selected GeoLink returns the error “DBFhandleSQLselectStatement:Could not open the DBF

....” because no DBF file is present. Both of these features of GeoLink work on the DBF file.

geolink v6.4 for digital aerial sketchmapping · 2012. 4. 25. · geolink v6.4 for dasm (25 april...

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