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Introduction
What's New?
Presentations and Publications
Use Cases
Hardware
Software
Data
FAQ
Participants
Contacts
Acknowledgements
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GeoPad Frequently Asked Questions (FAQ)
Most "problems" related to GeoPad are often best
addressed by visiting the support site for the specific hardware or
software item in question. Below are suggestions we have gathered for addressing
common issues that GeoPad developers
and users have reported as stumbling blocks.
Categories:
- What is a GeoPad or GeoPocket?
[27 September 2004]
"GeoPad" and "GeoPocket"
are a generic concepts: the integrated combination of GIS software, a GPS receiver,
and a Windows XP TabletPC (GeoPad) or a PocketPC Personal Digital
Assistant (GeoPocket). Furthermore, they should be easily
constructible from readily-available, off-the-shelf components, and
require a minimum of customization and IT-support.
-
ArcGIS vesrus ArcPad
Both of
these applications have a place in field education and research
activities. Generally speaking ArcGIS works for most GeoPad-type
applications and ArcPad works for most GeoPocket-type applications.
ArcGIS can only be run on a GeoPad (Tablet PC), whereas, ArcPad can
be run on both a GeoPad (Tablet PC) or GeoPocket (Pocket PC).
When using a GPS directly in mapping, ArcPad offers a richer
complement of tools for easy integration of GPS data into a map,
such as walking a contact to use the GPS trail as map data.
-
Overcoming difficulties in screen visibility when working with
grey-scale aerial photos. [27 September 2004]
In full-sunlight conditions it is
often difficult to see the details of gray-scale aerial photo in GIS
on transmissive TabletPC displays, such as the Xplore iX104 and
Panasonic Toughbook 18 use. In particular, we have found such
photos very problematic to work with during the brightest couple of
hours of the day, when the sky is cloudy or overcast. While
newer display technologies are improving the situation, here are a
couple suggestions to help out in the meantime:
- Adjust the contrast settings for the symbology of the photo
layer. This technique is best utilized by placing the
contrast control on the toolbar for easy access, as frequent
adjustments are required as you pan or zoom on the photo or
change position with respect to the Sun.
- Use a higher-contrast color-scheme for the symbology of the
photo layer, such as a typical "ROYGBIV"-style rainbow
collection.
Don't forget to visit
ESRI's own support
site for help with Arc Products!
- How do
I construct a custom toolbar in ArcMap, such as the
"Geologic Mapping"
toolbar used in University of Michigan courses?
[27 September 2004]
This "Geologic Mapping" toolbar was created using ArcMap's own customization
capabilities.
- Create a new toolbar -- From the "Tools" menu, select
"Customize...". On the "Toolbars" tab click on "New...".
Enter a name for your toolbar, like "Geologic Mapping", and
specify whether you want it saved in the default template "Normal.mxt"
or in a new template file.
- Add tools -- Adding tools to the new toolbar is as simple as
dragging them from existing toolbars (e.g., the TabletPC,
Editor, Effects, etc. toolbars).
- Modify toolbar buttons (e.g., rename tools, change button
images, etc.) -- You can modify the toolbar button
parameters by going "Tools" menu --> "Customize...". With
the Customize dialog up, you can then right-click on buttons to
modify their settings. (You can make simple images in
Paint to use with your buttons.) For example, we renamed
the button Outcrop and gave it a more meaningful image for our
geologic mapping use of it.
- Enlarge toolbar buttons -- You can toggle between using
small ("regular") and large buttons on the toolbar from "Tools"
menu --> "Customize..." --> "Options" tab. You can check
or uncheck, "Large icons". Using large icons toolbars
makes it easier
to hit the right thing when using the TabletPC pen.
- Lock toolbar customization -- To lock-down the toolbar so
that users do not accidentally move tools around, you can go to
"Tools" menu --> "Customize..." --> "Options" tab, and select
"Lock Customizations...". From there you can enter a
password that would be required to customize the settings
further.
- How do I clip
raster data sets?
[27 September 2004]
This is often desirable as a performance
advantage in the field. For instance, you might have a field
exercise that does not require the full 7.5" sheet, in which DRG
data sets are generally offered. If you reduce the data set
size, then the project will open faster and manipulate quicker (e.g.,
spin or fly-through in ArcScene), but be careful not sacrifice
necessary contextual data adjoining the field area.
There are two
types of raster data sets, single-band and multi-band, for which
ESRI's support site offers two suggested approaches:
- For a multi-band raster data set (e.g., files with
separate RGB color bands, such as a typical DRG file and generally
any scanned map you've stored as an image) see:
HowTo: Clip a multiband image using ArcGIS and Spatial Analyst
(Article ID 22526).
- For a single-band raster data set (e.g., files with a
single color band, such as black-and-white DOQQ files) see:
HowTo: Clip a raster dataset (Article ID 20887).
- Tip: when creating the shape file for the clip mask,
specify a spatial reference, it will probably save you time later on
when you want to use it for other purposes.
- Tip: if you are receiving a "Failed to evaluate the
calculator expression" from the raster calculator, check to make
sure you have a single-band and not a multi-band raster.
- How do I merge
raster data sets? [27 September 2004]
When have a number of rasters covering the
area of interest, such as multiple aerial photos (DOQQs), it is
often advantageous to combine them into a single raster for analysis
and manipulation purposes. See:
HowTo: Merge rasters using ArcGIS Spatial Analyst (Article ID 20988).
- Tip: you can combine merging and clipping steps by configuring
the "extent", while setting the options for the raster calculator,
to be a shapefile with your clipping polygon.
- Tip: if you are working with a multi-band raster, you need to
work with each band separately
- How
do I export/import symbology between rasters? [27 September
2004]
It is fairly
common when working with digital topographic maps (i.e., DRGs), that
you want to create a clipped version. After clipping, the
resulting raster has a default symbology that isn't very useful,
which you would like to replace with the symbology from the original
raster. See:
FAQ: Can I import or save raster layer symbolization in ArcMap?
(Article ID 18240).
- How do you georeference a raster?
[27 September 2004]
The ArcGIS help file gives
good instructions for this. Some notes follow:
- create a map document in ArcMap
- load a reference map with the same spatial coordinates
- load the scanned map you want to georeference
- make sure the scanned map is the selected Layer on the
Georeferencing toolbar
- using the "Add Control Points" tool, on the Georeferencing
toolbar, select a point on the scanned map, then select the point
with the correct coordinates on the reference map
- you can use "View Link Table" to bring up a table of the control
points, and edit points as needed
- then select "Rectify..." from the georeferencing toolbar menu
-
How
do I setup ArcMap to create a strike-and-dip symbol that is
properly rotated and labeled, when entering
mapping data? [27 September 2004]
ArcMap (ArcGIS/View
version 8.x and later) is capable out-of-the box of correctly
plotting and labeling strike-and-dip values as you map in the field.
To achieve this, you need to capture a minimum of two pieces of
information; the third item below is used to determine what symbol
is used, if you need to plot different types of strike-and-dip
symbols:
- dip-direction
- dip-angle
- strike-and-dip type (e.g., normal or overturned)
The following assumes that you are mapping multiple types of
strike-and-dip measurements (utilizing that third data field of
strike-and-dip type) and that dip-direction is measured as 0-360
degrees geographic:
- For the strike-and-dip layer's Symbology
- select "Categories - Unique values", with the "Value
field" set to the strike-and-dip type field
- some suggested symbols for each type are:
- normal -- Character Marker Symbol; font ESRI
Geology, Unicode 111; font-size 36
- overturned -- Character Marker Symbol; font ESRI
Geology, Unicode 115; font-size 36
- [For additional types, explore the rest of
the ESRI Geology font.]
- to rotate the symbols correctly, click on the
"Advanced..." button and select "Rotation..."
- set the "Rotate Points by Angel in this field" to
the dip-direction field
- select a "Rotation Style" of Geographic
- For the strike-and-dip layer's Labels
- select the dip-angle field as the "Label Field" for the
"Text String"
- for "Placement Properties...", select a placement of
"Place label at an angle specified by a field", and select
dip-direction as the "Rotation Field..." and Geographic as
the "Rotation Style"
-
ArcMap or ArcScene crashes unexpectedly.
[27 September 2004]
Increasing virtual memory appears to eliminate
a number of such crashes.
Details: Windows XP TabletPC, ArcGIS 8.3 SP2,
and 512MB RAM; running both ArcMap and ArcScene simultaneously,
actions in one of the programs would cause that application to crash
randomly. Increasing the virtual memory to 2GB (from 1GB?)
drastically reduced the number of unexpected crashes, but did not
completely eliminate them. (ESRI
KB Article 21658 is perhaps related and offers additional
possible fixes.)
-
ArcMap crashes when saving document.
[27 September 2004]
Fixed as of ArcGIS 8.3 Service Pack 3.
Details: Windows XP TabletPC, ArcGIS 8.3 SP2;
saving document crashes ArcMap. Was generally repeatable by
working on map for a bit, then clicking save; would work the first
couple of times, but then would fail. Appeared to only happen
after a personal geodatabase had been opened for editing (but could
be actively being edited or stopped) and after changing the view
(zoomed or moved the map), then all subsequent map document save
operations would crash ArcMap; however, if one did such actions
before starting to edit, then things went fine.
- ArcMap freezes when using a GPS. [27 December 2004]
Problem occurs with ArcGIS 9 Service Pack 2.
ArcMap usually freezes when you pan or zoom, apparently as a
result of becoming overwhelmed with the real-time flow of GPS data
and the redraw requests. The CPU is not overwhelmed, but
ArcMap becomes unresponsive. If given a few minutes it
sometimes recovers, sometimes crashes, or sometimes just stays hung;
usually we get out of the situation by killing ArcMap from the
Windows Task Manager. There are several things you can do
which reduce the performance demands and likelihood of freezing
ArcMap:
- Disable the GPS trail or keep it very short so that little
effort is required to redraw it when panning
- Reduce the baud rate of the GPS
- Use the "Minimum Display Rate" setting under "GPS Display
Options..." to reduce how often your positions is updated.
Don't forget to visit
ESRI's own support
site for help with Arc Products!
- Map projection Issues
- Only a limited subset of ArcMap's projections are supported
in ArcPad, so you should make sure to convert your data in
ArcMap beforehand; otherwise, the on-the-fly conversions may
result in large errors between layers (NAD27 versus NAD83 in UTM
Zone 11 in Wyoming gives a ~180 foot error).
iX104 (Xplore Technologies Field-Durable TabletPC)
- iX104 does not return from Standby.
[30 November 2004]
Fixed with BIOS version A2i.
Details: Sometimes when an iX104 was placed in Standby it would
not come out when the power button was pressed. The LEDs
indicated the unit was in Standby; "Status" was lit orange and
"Bright" was off. The only way to return the
unit to service was to press reset, and reboot from scratch.
(Units experiencing this problem had BIOS version A1p or A1s.)
-
Problems upgrading BIOS to version A2i to support new, long-life batteries (Li-Manganese 7600mAH-7.4V). [30
November 2004]
iX104 units with older BIOS (e.g., A1s) need to
have their BIOS upgraded to version A2i using an older battery
before they will work correctly with the new 7600mAH-7.4V batteries.
Details. BIOS version A2i is required for the 7600mAH-7.4V
batteries, however, you cannot upgrade from an older BIOS version
(e.g., A1s) with the new battery in the machine. When you try to charge
a new battery in an iX104 that has an old BIOS (e.g., A1s), then the
battery will only reach ~20%. When you try and run the BIOS upgrade
to A2i, it
complains that there is not enough charge in the battery to run the
upgrade, nor can you run it without the battery present, because in either
case, you get a yes/no question that you cannot answer without a
keyboard. You can circumvent this problem by upgrading to the
new A2i BIOS using an old battery, prior to installing the
7600mAH-7.4V battery.
See
iX104 Technical
Update Bulletin (Document ID IX104TU082304_v1) for details on
the new batteries and how to obtain a compatible BIOS.
-
Problems with old, long-life batteries (9000mAH-6.4V) failing.
[30 November 2004]
Long-life 9000mAH-6.4V batteries shipped
with iX104s in early 2003 are prone to fail, however, Xplore will
replace them free-of-charge.
Details: Many of the long-life (9000mAH-6.4V) batteries
that we originally purchased with our iX104's in spring 2003 began
failing by mid-2004, after about a year of use. Several
batteries stopped holding charges for as long as expected and two
swelled up and completely stopped working. When contacted
regarding the problem, Xplore replaced all of our batteries
free-of-charge, including those that were still functioning
correctly; they were replaced with the newer, 7600mAH-7.4V
batteries. (See
note about steps required to use the 7600mAH-7.4V battery in
iX104s with a pre-A2i BIOS.)
-
Display flickers
intermittently. [7 August 2005]
The iX104 display
flickers and applications repeatably attempt to redraw the screen
(maxing out the CPU) when the metal clamp on the iX104 stylus tether
shorts across pins on the bottom snap-on connector. The
solution is to cover the clamp with something non-conductive, such
as duct tape.
-
Which ArcGIS projection file does one use for the "Michigan GeoRef"
projection? [26 December 2004]
For data sets downloaded from the
MI Geographic Data
Library, which use the "Michigan GeoRef" projection, the
equivalent in ArcGIS is "NAD 1983 Michigan GeoRef (Meters).prj".
When you need to specify the spatial reference properties on such a
data set, look for this projection at:
Coordinate Systems\Projected Coordinate Systems\National Grids\NAD 1983 Michigan GeoRef (Meters).prj
-
Where can I get a hands-free harness for my GeoPad?
We feel
the hands-free harnesses or shoulder harnesses is a critical factor
in ease-of-use for the GeoPad. The harness appearing in some
of the pictures on this site is an accessory sold by Xplore for
their iX104 line of Tablet PCs. We have not (yet) seen another
company offering a similar option for their ruggedized Tablet PCs.
An inquiry to our local sporting goods store regarding the custom
manufacturing of such a harness out of ballistic nylon put the cost
at ~$100.
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