Subject: Marine Geospatial Ecology Tools (MGET) help
Text archives
| From: | "Jason Roberts" <> |
|---|---|
| To: | <> |
| Cc: | <> |
| Subject: | RE: [mget-help] Re: 'Create raster' and 'create climatological raster' difference in MGET |
| Date: | Mon, 21 May 2012 15:29:30 -0400 |
Nathan,
The "Create Rasters" tools download a series of rasters where each raster is
a time slice of some product, or in the case of 4D products such as HYCOM or
ROMS, a time-and-depth slice. Each raster has a date. For some products, such
as AVISO, the raster represents the estimated instantaneous conditions on
that date. For other products, the raster represents an average over a period
of time (e.g. 8 days, one month, or one year), usually starting on the date
of the raster. To know more, you should read the documentation for the tools
and the products themselves.
The "Create Climatological Rasters" tools download a series of time slices
and create one or more statistical summaries of the entire series. You must
specify what kind of statistic you want (mean, maximum, standard deviation,
etc) and what type of "bins" you want: cumulative (all time slices sorted
into one bin), monthly (slices sorted into 12 bins, according to their
month), or daily (slices sorted into bins according to their day of the
year). The tool sorts the slices into the selected bins, then computes the
statistic for each pixel using all of the slices in the bin. For example, if
you have 10 years of daily slices and compute a monthly climatology, the tool
will output one raster for each month. The first one, January, will combine
the 310 images that occurred in the month of January (10 years x 31 days in
January = 310 slices total).
If you have some points and just need to obtain values equivalent to those
output by the "Create Rasters" tools, then you should use the corresponding
"Interpolate XXXXX at Points" tool. That tool performs the equivalent to
creating the raster and then running the ArcGIS Spatial Analyst Extract
Values At Points tool (although it does not use that tool internally).
If you have some points and you need to obtain *climatological* values, then
the "Interpolate XXXXX at Points" tool will not do what you want. Instead you
should use "Create Climatological Rasters" and then use Extract Values At
Points (or alternatively use MGET's Interpolate Raster Values At Points,
which performs an equivalent operation).
Best regards,
Jason
-----Original Message-----
From:
[mailto:]
Sent: Monday, May 21, 2012 10:13 AM
To:
Subject: [mget-help] Re: 'Create raster' and 'create climatological raster'
difference in MGET
Dear MGET,
Thank you for a wonderful product, as well as for the amount of help you
provide to users. I have a quick question regarding the differences among
tools within the "Data Products" section of the toolbox. For many of the
data products, such as AVISO products for example, there are two difference
options for creating rasters. The first starting with "Create rasters for
'X' product", and the second being "Create Climatological Rasters for 'X'
product." What is the difference between these two tools? I am simply
wishing to create rasters to both extract oceanographic parameters from point
locations (although it appears the new tool "Interpolate X product at Points"
will do this for me(!), as well as to identify the position of oceanographic
features on certain dates/weeks.
Thank you for all of your help, and I apologize for the simpleness of my
question.
Sincerely,
Nathan
The "Create Rasters" tools download a series of rasters where each raster is
a time slice of some product, or in the case of 4D products such as HYCOM or
ROMS, a time-and-depth slice. Each raster has a date. For some products, such
as AVISO, the raster represents the estimated instantaneous conditions on
that date. For other products, the raster represents an average over a period
of time (e.g. 8 days, one month, or one year), usually starting on the date
of the raster. To know more, you should read the documentation for the tools
and the products themselves.
The "Create Climatological Rasters" tools download a series of time slices
and create one or more statistical summaries of the entire series. You must
specify what kind of statistic you want (mean, maximum, standard deviation,
etc) and what type of "bins" you want: cumulative (all time slices sorted
into one bin), monthly (slices sorted into 12 bins, according to their
month), or daily (slices sorted into bins according to their day of the
year). The tool sorts the slices into the selected bins, then computes the
statistic for each pixel using all of the slices in the bin. For example, if
you have 10 years of daily slices and compute a monthly climatology, the tool
will output one raster for each month. The first one, January, will combine
the 310 images that occurred in the month of January (10 years x 31 days in
January = 310 slices total).
If you have some points and just need to obtain values equivalent to those
output by the "Create Rasters" tools, then you should use the corresponding
"Interpolate XXXXX at Points" tool. That tool performs the equivalent to
creating the raster and then running the ArcGIS Spatial Analyst Extract
Values At Points tool (although it does not use that tool internally).
If you have some points and you need to obtain *climatological* values, then
the "Interpolate XXXXX at Points" tool will not do what you want. Instead you
should use "Create Climatological Rasters" and then use Extract Values At
Points (or alternatively use MGET's Interpolate Raster Values At Points,
which performs an equivalent operation).
Best regards,
Jason
-----Original Message-----
From:
[mailto:]
Sent: Monday, May 21, 2012 10:13 AM
To:
Subject: [mget-help] Re: 'Create raster' and 'create climatological raster'
difference in MGET
Dear MGET,
Thank you for a wonderful product, as well as for the amount of help you
provide to users. I have a quick question regarding the differences among
tools within the "Data Products" section of the toolbox. For many of the
data products, such as AVISO products for example, there are two difference
options for creating rasters. The first starting with "Create rasters for
'X' product", and the second being "Create Climatological Rasters for 'X'
product." What is the difference between these two tools? I am simply
wishing to create rasters to both extract oceanographic parameters from point
locations (although it appears the new tool "Interpolate X product at Points"
will do this for me(!), as well as to identify the position of oceanographic
features on certain dates/weeks.
Thank you for all of your help, and I apologize for the simpleness of my
question.
Sincerely,
Nathan
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