FREQUENTLY ASKED QUESTIONS ABOUT THE ALASKA FIRE PERIMETERS DATABASE:

1. How long will you be providing coverages for fire history?
ANSWER:  Coverages have been phased out.  The 2004 Fire History was the 
last year coverages were produced. Fire history datasets are now being 
provided in shape files(.shp) and personal geodatabases(.mdb).


2. Why do I get labels where there are no fire perimeters?
ANSWER: There are aproximately 300 records for which no mapped perimeter has 
been located. These were included as a 10 meter buffer around the reported point 
of origin. They are generally so small that you do not see them, but if you auto-label
the theme in ArcMap, they will get labeled.  

3. How can I identify these tiny buffers around points?
ANSWER: By selecting on the Boundary attribute field.  There are three unique
values in the boundary field:

	Y -- region is a mapped fire perimeter.  In this instance, acres
		are acres in the digitized perimeter.
	N -- region is a 10 m buffer around a reported point of origin.
	     	In this instance, the acres are acres reported in the incident
		report.


4. Why don't the fire perimeters line up with my other layers?
ANSWER: This feature class is stored in a geographic projection (double precision,
decimal degrees) referenced to the NAD83 datum.  For more information, refer 
to your software documentation on projections and coordinate systems.

5. What do you plan to do about the 300 missing fire perimeters?
ANSWER: Filling in these perimeters is not a high priority.  They are all more
than 20 years old, and the quality of perimeter maps made at the time of the
fire is likely to be very poor.  As projects involving satellite imagery and
aerial photography come up, and as time permits, perimeters that are discernable
on the imagery will be noted and placed on a list for automation when staff
time is available.  When updated, the "Comments" field in the attribute table
will indicate the reason and year the perimeter was updated.

6. How accurate are the fire perimeters?
ANSWER: That varies considerably.  Fires mapped within the past 15 to 20 years
are expected to be within +- 200 m of the actual location.  Fires mapped prior
to that may be up to +- 500 m.  The maximum allowable RMSE of map registration
during digitizing was 20 ground meters.  No formal assessment of positional
accuracy has been conducted.