optimizing cache levels for high resolution aerial imagery€¦ · usda forest service, remote...

USDA Forest Service, Remote Sensing Applications Center, FSWeb: http://fsweb.rsac.fs.fed.us

WWW: http://www.fs.fed.us/eng/rsac/

Optimizing Cache Levels for High Resolution Aerial Imagery

James Monty RedCastle Resources, working onsite at

Remote Sensing Applications Center Salt Lake City, UT

USDA Forest Service, Remote Sensing Applications Center, http://fsweb.rsac.fs.fed.us

Outline

of Imagery in the forest

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I m a g e c a c h e s

How we solved the issue


Imagery in the Forest Service

Each National Forest has been photographed many times, some as far back as the 1930’s and ‘40’s.

1930 1950 1970 1990 2010 Future

Widespread use of Natural Color & CIR Aerial Photos and 4-band Digital in USDA Forest Service

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Presentation Notes

Snapshots in time!



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Rich history of frame photography, with some oblique from the 30’s (top) through the 70’s (bottom) and 80’s. Previously our forests would share imagery on local drives. Finding that for many projects there is a need to more easily share imagery without having it on a number of computers. Also a push within the Forest Service to centralize data.



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Some forests finding use in commercial sat Lidar gaining momentum as use knowledge expands


Imagery Use in the Forest Service

• Capture current state



• Capture current state • Planning

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Mix use of NAIP and RP



• Capture current state • Planning • Harvest

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Particularly AK with their own platform – used in conjunction with ground work to do estimates



• Capture current state • Planning • Harvest • Vector updates



• Capture current state • Planning • Harvest • Vector updates • Change analysis

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Use NAIP pair of an fire location



• Capture current state • Planning • Harvest • Vector updates • Change analysis • Image derived products

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FVMs, RDW, atlas



forest-atlas.fs.fed.us

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FVMs, RDW, atlas



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Image server use For me: primarily image services Others are creating map and feature services, but most are uncached


Challenge in High Res Imagery

Typical user views:

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Our users like to view at ‘insect scale’ Three images: Small scale Large scale Insect scale


Image Server caches

• Analogous to reduced resolution layers.

• Image tiles delivered to user’s computer.

• Improve redraw rate in revisited locations.

Graphic :ESRI training


Image Server caches

L19 1:1,128

L18 1:2,257

L17 1:4,514

L16 1:9,028

L15 1:18,056

1:13,542

1:6,771

1:3,386

1:1,693

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Presentation Notes

Default values – show levels on right hand side graphic so it can be used through the next few slides. Discuss the range that a cache level appears, and how the undesired affect occurs near the upper end.


The issue For resource photography, service caches have poor appearance at large scales

Cached Dynamic

6 inch imagery; L17 cache

L19 1:1,128

L18 1:2,257

L17 1:4,514

L16 1:9,028

L15 1:18,056

1:13,542

1:6,771

1:3,386

1:1,693


The issue

30 cm imagery; L17/L18 cache break

1:1700 1:1680

L19 1:1,128

L18 1:2,257

L17 1:4,514

L16 1:9,028

L15 1:18,056

1:13,542

1:6,771

1:3,386

1:1,693

For resource photography, service caches have poor appearance at large scales


Potential Solutions

Just throw more cache levels at it - Most caches go to L17 - Add L18 and L19 Create our own pixel sizes/scales at finer cache levels

L19 1:1,128

L18 1:2,257

L17 1:4,514

L16 1:9,028

L15 1:18,056

1:13,542

1:6,771

1:3,386

1:1,693

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Presentation Notes

Adding caches does not address the issue of blurry trees near the level breaks Transition: how do we decide on new levels??


Developing New Cache Levels

Default scale levels are factored at 0.5

Looked into a variety of new factors from 0.6 to 0.8

Level Scale (1:)

Pixel (m)

15 18056 4.77

16 9028 2.39

17 4514 1.19

18 2257 0.59

19 1128 0.29

20 --- ---

21 --- ---



Current levels (0.5)

Level Scale (1:)

Pixel (m)

15 18056 4.77

16 9028 2.39

17 4514 1.19

18 2257 0.59

19 1128 0.29

20 --- ---

21 --- ---

Level Scale (1:)

Pixel (m)

15 18056 4.77

16 12639 3.34

17 8847 2.34

18 6193 1.64

19 4335 1.15

20 3035 0.80

21 2124 0.56

Option 1 (0.700)



Current levels (0.5)

Level Scale (1:)

Pixel (m)

15 18056 4.77

16 9028 2.39

17 4514 1.19

18 2257 0.59

19 1128 0.29

20 --- ---

21 --- ---

Level Scale (1:)

Pixel (m)

15 18056 4.77

16 11736 3.11

17 7629 2.02

18 4959 1.31

19 3223 0.85

20 2095 0.55

21 1362 0.36

Option 2 (0.65)

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Presentation Notes

Since most of our resource photography is flown to provide a 25 – 30 cm pixel, these seemed like the ideal level for the finest cache.



Improvement at the break

L19 1:3,574

L18 1:5,358

L17 1:8,033

L16 1:12,043

L15 1:18,056

1:14,896

1:9,683

1:6,294

1:4,091

1:2,659

1:1,728

L20 1:2,383

L21 1:1,589

30 cm imagery; L20/L21 cache break

1:1720 1:1740



L19 1:3,574

L18 1:5,358

L17 1:8,033

L16 1:12,043

L15 1:18,056

1:14,896

1:9,683

1:6,294

1:4,091

1:2,659

1:1,728

L20 1:2,383

L21 1:1,589

Easier to find the insects

Presenter

Presentation Notes

Our users can now see the trees in the forest more easily, and also find their insects. Mention that the increase required just under twice as much storage


Takeaways

» Finding that ArcGIS for Server is more flexible than the older server version


Takeaways


» Don’t just accept the defaults; experiment


Takeaways


» Don’t just accept the defaults; experiment » That said, only frustration: cache levels

and AGOL


Takeaways


» Don’t just accept the defaults; experiment » That said, only frustration: cache levels

and AGOL » Questions or issues? Wondering about

what others have tried or seen? Hit up the user community. (GeoNet)

Presenter

Presentation Notes

Questions or issues? Wondering about what others have tried or seen? Hit up the user community. (GeoNet)

USDA Forest Service, Remote Sensing Applications Center, FSWeb: http://fsweb.rsac.fs.fed.us

WWW: http://www.fs.fed.us/eng/rsac/

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Optimizing Cache Levels for High Resolution Aerial Imagery

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optimizing cache levels for high resolution aerial imagery€¦ · usda forest service, remote...

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