New GIS Tools - Build Custom Queries and Set Spatial Filters

Get better search results with queries and filters


Last month a new search tool became available to users of the Online Survey Research GIS.  The new tool allows users to build custom queries and set spatial filters. Watch the video and read the post to maximize the GIS and get better search results.

GIS access: http://maps.smcgov.org/GE_4_4_0_Html5Viewer_2_5_0_public/?viewer=raster

Dense polygon clusters:
Set a spatial filter when the screen is crowded with polygons. This will display small symbols to click rather than the polygons which can be clumsy when they're in a dense cluster.

Before filter:

Multiple polygons make selecting a single map difficult

After filter:

Smaller symbols help with selecting a single map in a crowded screen

Overlapping polygons:
Areas that have been surveyed more than once will sometimes cause polygons to hide other polygons. Setting filters will reveal all maps in the area with different symbols that still have all of the attributes of the polygons.

Before filter:

On two areas of this screen a corner record polygon is being hidden by a larger corner record polygon.

After filter:

Setting a filter will reveal all maps and display a different symbol to click and retrieve the map.

Faster searches in rural areas and higher zoom:
Map polygons are only displayed when the GIS reaches a zoom level of 1" = 600' which is acceptable for most conditions.  When searching large areas (higher than 1" = 600') a filter will display maps by symbol rather than polygon.

Before filter:

No results for Records of Survey at 1 inch = 0.5 mile

After filter:

All Records of Survey shown; click each symbol to download the map.

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Email pw-surveying@smcgov.org  with questions or for more details

2016 Road Projects and Monument Preservation

San Mateo County Public Works has just begun our busy time of the year for road projects. For the Surveying group this mean we've just completed our pre-construction monument preservation tasks.  2016 marks our second full construction cycle of employing some new procedures and technology for monument preservation.

The sections of proposed road work and survey monuments in the same GIS is an excellent tool for analysis and planning.

The procedure:
The Surveying group obtains the locations of road projects from the Engineering group and adds them to a web based GIS map. The GIS map now serves as a mobile map the Survey group can access in the field from any mobile device. Any monument we encounter within the proposed road project area is surveyed and the monument is added to the same GIS map.  This provides an excellent tool for analysis and planning of our monument preservation activities.

A proposed slurry seal project in El Granada and the details of a survey monument along with a photo in the GIS map.  This is an internal and external tool for everyone working on the project.

The technology:
Our team did an evaluation of best procedures for sharing monument location and descriptions.  We compared the previous method of paper maps and how stakeholders accessed them to a online GIS and well...GIS is superior in every way imaginable.  For the surveyors reading this, we still file the necessary corner records and records of survey.  This GIS is aimed at creating an easy to access system for the public, pavement and utility contractors, and any government entity that works in the roads or issues permits for road work.

GIS data collection In addition to traditional total station and GPS data collection, our team is using ArcGIS Collector to populate an ArcGIS Online web map.  ArcGIS Collector runs on any smartphone or tablet and we wrote a detailed post in October 2015 about how we collect the data.

ArcGIS Collector for smartphones

Sharing the data
As we mentioned earlier, previous monument preservation processes logged the data in paper format which was difficult for other groups to access even when scanned and shared electronically.  Often when these paper maps or scans were accessed, non-surveyor/engineer personnel struggled to interpret the location and description of the monuments and whether a proposed project would affect the monuments. This generated a bottleneck in the data flow that we were able to clear with ArcGIS Online.  ArcGIS Online allows anyone with an internet connected PC, phone, or tablet to see the monument locations in a GIS environment that can be customized to the users liking.

Users can customize the basemap of the GIS to their liking.

Users can see photographs of each monument and the description the field crew added.  The sample below is a disk in concrete 0.10 feet from the edge of the AC paving.  A total road reconstruction project would endanger this monument where a slurry seal project wouldn't.  The photo and description are key components to our analysis of monument preservation efforts needed per project.

Want to check out the Survey Marker GIS?

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iPhone and iPad User Tips

On June 24th, San Mateo County's online map research GIS migrated to a new interface with a new URL. Access the new site here or paste the following URL into your browser:

http://maps.smcgov.org/GE_4_4_0_Html5Viewer_2_5_0_public/?viewer=raster

The video below highlights the iOS device access that the previous GIS didn't have and provides a couple of important tips for iPhone and iPad users.

Subscribe to our YouTube channel or this blog to be kept in the loop with changes.

Online Survey Research - New URL and Enhancements

On June 24th, San Mateo County's online map research GIS migrated to a new interface with a new URL. Access the new site here or paste the following URL into your browser:

http://maps.smcgov.org/GE_4_4_0_Html5Viewer_2_5_0_public/?viewer=raster

It is significantly different and we have put out some how-to videos to help with the transition.  We're certain more will follow but for now check out the playlist below.  Subscribe to our YouTube channel or this blog to be kept in the loop with changes.

Email pw-surveying@smcgov.org  with questions or for more details

How to turn layers on/off to see map extents.  How to view / download.

How to search by book and page. How to view / download.

Change the basemap of the research GIS