Imagery Best Practices

Supporting Imagery and Lidar in the ArcGIS platform has been around for a long time. In the ArcGIS Server Space, Image Server became available at 9.3.1. Since then it has evolved to Mosaic Datasets, Image Services, Raster Functions and now raster analytics. Now imagery is really an integral part of the ArcGIS platform. However, it is only as performant when the imagery is managed and configured optimally.

I often get asked,

• what format should I store my imagery in?,
• How many images can be in a Mosaic Dataset?
• How should I structure my imagery? and
• what is the maximum number of images per folder?

When answering these questions I have drawn on past experience and advice from Esri. Now though Esri have compiled all this information into an Excellent Centralised resource Imagery Workflows – Best Practices https://doc.arcgis.com/en/imagery/workflows/best-practices/what-are-best-practices.htm

In the Imagery formats and Performance section it details topics such as:

• File format suitability
• Recommended imagery formats
• Reformatting imagery
• Pyramids
• Statistics
• Working with large mosaics
• Storage system performance

If you’re going to be managing imagery and lidar I recommend you reads these documents. They are comprehensive and invaluable. I must admit I have been doing this for 12 years now and there is information on Lidar management that I did not know about.

This is just one component of the ArcGIS Imagery Workflows documentation Esri has just produced.

Gordon

Problem: Severe issue with ArcGIS Pro 2.2 Patch 2

Description

Esri has discovered a severe issue with an editing workflow in ArcGIS Pro 2.2 Patch 2 (2.2.2) that may incorrectly set feature attribute field values to ‘Null’ when using the Attributes pane.

Cause

This problem occurs when multiple features are selected in the tree view of the Attributes pane. If the Tab key is used to navigate between cells in the data grid, tabbing through a cell that displays “(Different values)” sets the field to ‘Null’.

Solution or Workaround

Esri strongly recommends to uninstall the patch.

1. On Windows, open the Control Panel.
2. Search for View installed updates. Click this option.
3. Right-click ‘ArcGIS Pro 2.2 Patch 2 (2.2.2)’ and select Uninstall.

If the previous patch—ArcGIS Pro 2.2 Patch 1 (2.2.1)—is not installed, it can be downloaded from My Esri.

How will Esri correct the issue?

ArcGIS Pro 2.2 Patch 3 (2.2.3) becomes available in early October 2018 and includes a fix for this issue, as well as the other software improvements included with Patches 1 and 2. ArcGIS Pro 2.2 Patch 2 (2.2.2) is no longer available for download.

For continued updates and information regarding this problem, refer to the ArcGIS Pro 2.2.2 announcement on GeoNet.

Esri have also published the following technical article relating to this issue:  https://support.esri.com/en/technical-article/000019162

Update 05 Oct 2018: ArcGIS Pro 2.2 Patch 3 (2.2.3) is available for download from My Esri.

If you have any questions or concerns, please contact your local Esri distributors support team (for Esri Australia clients, use My Esri, support@esriaustralia.com.au or 1800 447 111)

GDA94, GDA2020 and WGS84; The projection dilemma

Progress supporting GDA2020:

The Intergovernmental Committee on Surveying and Mapping (ICSM) & Geoscience Australia (GA) recently released the definitions for the GDA2020 datum and associated projected coordinate systems covering Australia and its territories. Esri Australia has been working closely with ICSM & GA to ensure that ArcGIS software products support the new definitions.  Version 10.6 of ArcGIS and version 2.1 of ArcGIS Pro both include support for the new datum and projected coordinate systems (you can learn more in the Esri Australia Technical Blog)

Avoiding alignment issues mixing datums:

Web GIS, by default, displays data in the projection WGS84 Web Mercator (auxiliary sphere). When mapping data is shared to ‘Web GIS’, data is automatically reprojected ‘on-the-fly’ to this web projection in order to align with the displayed basemap and fit with the global projection. Most users do not realise that their data is being reprojected and in many instances occurs without issue.

However, while organisations are migrating to GDA2020 from GDA94 and using mixed data containing both datums, these mixed data sources will create a challenge when displayed in WGS84. The issue occurs when data is reprojected to the WGS84 Web Mercator projection.  

GDA2020 & ArcGIS

It is now official on the 15th of December 2017 Geoscience Australia and the Intergovernmental Committee on Survey and Mapping (ICSM) launched the new GDA2020 datum.

In support of the new Australian datum, the following tools and resources have also been released by Geoscience Australia and ICSM:

• the ICSM GDA2020 Technical Manual
• additional ICSM datum modernisation Fact Sheets
• GDA94 to GDA2020 Transformation Grids
• Geoscience Australia’s GDA94 to GDA2020 Online Transformation Service
• AUSGeoid2020 to convert GDA2020 ellipsoid heights to the Australian Height Datum.

So what does this mean for the ArcGIS product suite? Well from ArcGIS Pro 2.1 and ArcGIS 10.6 onwards all state, territory and national projections that incorporate the GDA2020 datum are supported.

Georefencing workflow made easier with ArcGIS Pro

Do you often have to georeference raster datasets? Do you find a lot of time is consumed with setting up control points?

Georeferencing was introduced with ArcGIS Pro 1.4 and has the capability to speed up your georeferencing workflows. Auto georeference allows you to automatically georeference your raster dataset to a referenced raster dataset (this can even be a basemap from your Portal or ArcGIS Online). The automated control points are based on the spectral signatures of different locations across the images, so this method is best suited for aerial and satellite imagery which are similar in nature.

R-ArcGIS Bridge – Improving methods of statistical analysis in ArcGIS

The R-ArcGIS Bridge is a little-known secret to improving your methods of geostatistical analysis. By integrating ArcGIS and R you can have the best of both geospatial and statistical platforms. With the R-ArcGIS Bridge you and I can now perform and visualise comprehensive statistical analysis directly in ArcGIS Desktop.

 

Why would you use R?

R is a powerful platform for solving big data science problems. R is both an open source language and programming environment, widely used for statistical analysis. R offers an online repository with 6,400 statistical problem-solving packages.

The R-ArcGIS Bridge is a way to load your spatial data into R, or, create custom Geoprocessing Tools in ArcGIS that leverage the capabilities of R. The Bridge can be directly connected to either ArcGIS Pro (version 1.1+) or ArcMap (10.3.1+), and R (3.1+) or RStudio. The R-ArcGIS Bridge can then be used with pre-existing tools written in R, without the need to learn any code!

There are several uses of R-ArcGIS Bridge:

• Use R functions to read and write spatial data
• Convert between data types
• Solve complex geostatistical problems
• Write, configure, and modify an R script to be executed from a Geoprocessing tool
• Share an R script with others as a toolbox

 

How do I get started?

ArcGIS Pro for Imagery Analysis

In previous blogs, I have spoken about how imagery can be utilised within the ArcGIS Platform and how it can be analysed. Through all this it has been about imagery can be viewed downstream. What about the prepossessing or specialised analysis not through web services? Well this is where ArcGIS Pro comes in.

In 2017 Esri has stated that their goal is for ArcGIS Pro to be functionally equivalent or better than the current toolsets in ArcMap. To this end in ArcGIS Pro 1.4 Esri have included a new core tab, Imagery. Core tabs are always on and accessible unlike layer specific tabs which only appear when an entry is selected in the Table of Contents.