ArcGIS tips

Workshop 2012 (Spring) - Mapping from Total Station data in Arcmap 10

nico — Thu, 05 Apr 2012 21:13:05 +0000

This workshop walks through the process of generating maps from Total Station data in Arcmap. It is developed on ArcGIS 10.0 (sp4) and therefore tools and procedures may be different in other versions. The basic procedure involves saving the SDR file generated by SokkiaLink into a Point shapefile, then using the Points to Line and the Feature to Polygon tools in ArcToolbox Data Management Tools to convert these points into polygons. Finally we generate a map using these data.

Workshop 2008 - Maps Linking GPS and Lab Results

nico — Fri, 22 Feb 2008 20:04:05 +0000

Archaeological Research Facility at UC Berkeley
PRACTICAL WORKSHOP
Working with Archaeological survey data in Arcmap 9.2:
Making maps that link GPS point locations with artifact-level lab data
Friday Feb 22, 2008
N. Tripcevich

If images are absent in the webpage below, please Reload the webpage and allow it to load completely.

Data used in workshop:

The Effects of the Curvature of the Earth, the Refraction of Light in Air, and Fuzzy Viewsheds in ArcGIS 9.2

Mon, 28 Jan 2008 02:24:30 +0000

In making viewshed calculations, the earth's curve and the refraction of light in air have an impact (albeit minor) on lines of sight. I this post, I provide some links describing how Arc calculates both variables. I would love to find out how to recalculate the "refractivity coefficient" of 0.13 to other situations. I also put a plug in for fuzzy viewsheds, a drastic improvement that was first suggested 15 years ago, to be mostly ignored in practice until very recently.

Corrections for the Curvature of the Earth

Finding the right transformation when re-projecting data in ArcGIS 9.2

Thu, 17 Jan 2008 05:45:41 +0000

So you're using the Project Tool to re-projecting a map into a new projection.

Before you can start the process, you have to choose from the many transformations. The attached file (World Projections.xls) lists where in the world each projection transformation should be used.

For example, if your map is in PSAD56, and you want to project it to WGS84, the Project Tool will ask you which transformation you want. Checking the lists for Bolivia, I find: PSAD_1956_To_WGS_1984_2

Finding the right transformation when re-projecting data in ArcGIS 9.2

Thu, 17 Jan 2008 05:43:45 +0000

So you're using the Project Tool to re-projecting a map into a new projection.

Before you can start the process, you have to choose from the many transformations. The attached file (World Projections.xls) lists where in the world each projection transformation should be used.

Batch DEM -> GRID AML for ArcGRID

nico — Sun, 15 Apr 2007 00:19:40 +0000

When you get many small tiles of data from sources like
http://data.geocomm.com/catalog/index.html

(a source of 1:24,000 DEMs for the contiguous US states)

You often need to batch convert these files to a native ESRI format.

Here's an AML to run at the GRID command to convert all DEM files in the folder to GRID

Creating LZW compressed TIFF files outside of a Geodatabase

nico — Fri, 23 Mar 2007 12:50:34 +0000

generating a compressed GeoTIFF for ArcGIS that is outside of a Geodatabase

Software: ArcGIS 9.2, Adobe Photoshop

Question

Experimenting with raster compression formats with a scan of a ~D sized paper map (300 dpi) I found that after georeferencing (using Lat/Long) I could create a 18mb JPG file together with its JGW worldfile at about 80% JPG compression. How large would this file be in a non-lossy format that is widely readable by non-GIS users?

Setup Batch processing in ArcGIS 9.2 with Excel

nico — Thu, 22 Feb 2007 15:52:04 +0000

Setup Batch processing in ArcGIS 9.2 with Excel

With v9.2 ESRI has brought a useful batch processor to most of the toolbox functions.

Right-clicking the item in the toolbox view shows the "Batch..." command.

The matrix of cells that appear in the Batch command can be difficult to fill-in, however I've found that you can construct a more elaborate batch in MS Excel and then paste those values back in to the ArcGIS batch window.

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Cartographic transformations in ArcGIS for South America

nico — Fri, 03 Nov 2006 18:10:52 +0000

ArcGIS offers a number of geographic transformations between coordinates in the older Prov South American Datum of 1956 (PSAD56) and the modern WGS 1984 datum.

ESRI Press has published a book on this topic titled "Lining Up Data", 2010.

Finding the PSAD1956 datum in ArcGIS

The PSAD1956 datum is supported in ArcGIS. The coordinate system settings are found under Coordinate System menus under UTM (Universal Transverse Mercator)

Vector-border Technique for Reprojecting Rasters

nico — Wed, 01 Nov 2006 14:43:34 +0000

Vector-border Technique for Reprojecting Rasters

Summary: This technique allows a user to bring scanned maps and other rasters from a variety of projections and coordinate systems into a common reference system. The idea is that a vector file can be transformed more easily than a raster file, so a vector border of a raster map is transformed (in lieu of the raster itself), and then the raster is re-georeferenced to the new vector position.

Week 4 - Queries, relates, and buffers

nico — Mon, 23 Oct 2006 20:13:29 +0000

Classroom Topics

Further discussion of database normalization and relates, overlays, buffers, and other means of working with GIS data in a relational database structure.

In class presentations.

In-Class Labwork, Week 4

Manipulating data through queries, overlays, and other methods become more complex with relational databases, but understanding how to work with these data is fundamental to organizing a project in digital structure.

Fieldwork with GPS in South America: PSAD 1956 (La Canoa) or WGS84 datum?

nico — Wed, 11 Oct 2006 18:45:59 +0000

Provisional South American Datum of 1956

Maps published in a number of Andean countries in South America (i.e., Ecuador, Peru, Bolivia) are still often based on the Provisional South American Datum of 1956, La Canoa (Venezuela), abbreviated to “PSAD56”.

Week 2 - Data organization and management

nico — Mon, 02 Oct 2006 11:49:04 +0000

Classroom Topics

This week's class will focus on data organization and management for GIS applications to anthropological research. Specifically, we will spend time discussing the importance of relational databases and means of organizing and querying data organized into related tables.