for questions related to implementing best practices to ensure good quality in gespatial datasets; including quality assurance (QA) and quality control (QC)

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1answer
19 views

Discrepancy between shape area and data from municipality [closed]

I am attempting to map several parcels just to show very basic dimensions (frontage, etc.) and parcel area. I have the parcel area from the municipal assessor's office in acres. And I have a parcel ...
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0answers
46 views

MODIS Quality Control in QGIS

I have to process 46 MODIS MOD15A2H images (leaf area index) in QGIS 2.12 Lyon. I have to clean the images from bad pixels using MODIS Quality Control. Is there any method to automate the process for ...
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0answers
21 views

MOD09A1 QC layer

Does anyone know how to handle MOD09A1 Quality flags (QC) in in R? I was trying to use raster package but unable to unlock the QC band.
2
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1answer
20 views

How can I select ways that have missing access parameters “[key]=Not Specified”?

Follow up to How can I programmatically identify missing sidewalks in OpenStreetMap data?. I've noticed that a number of streets and roads in a region I'm interested in are missing pedestrian access ...
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2answers
71 views

How can I programmatically identify missing sidewalks in OpenStreetMap data?

I have a web map that is using the pedestrian routing from Mapbox's directions API. However, users have seen very long circuitous paths in certain locations because it appears that sidewalks (and/or ...
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0answers
26 views

SDS for quality assurance MODIS data

Can anyone help me with which quality assurance data to use for MODIS MCD43A4? The QA dataset for this is MCD43A2 which has 4 SDS - Science Data Sets (HDF Layers) 4 UNITS BIT TYPE FILL ...
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2answers
132 views

How to correctly parse MODIS QA layers?

I'd like to correctly parse the MOD13Q1 VI Quality layer (see Table 2 in "layers" here). For this, I'm trying to follow Example 1 from this tutorial (page 10). I'll illustrate my problem with a pixel ...
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0answers
31 views

Changes in MOD09A1 quality mask as processed with GDAL

I'm analyzing MOD09A1 spectral data using GDAL/Python. The quality mask is a uint32 dataset and want to pull out the value of the first bit to mask the spectral data (1 == poor data; 0 == good data). ...
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2answers
98 views

Why are my raster images losing quality when they are clipped?

I'm using the ArcGIS data management clip tool for raster, a jpg file. It is being clipped with a polygon. After the clip is successful, the clipped image is appearing in lower quality and the colors ...
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2answers
60 views

Implementing transactions with Collector for ArcGIS?

Currently I am looking into using ArcGIS Collector for field use. I would like for there to be a QA process done before final submission. Is there a way to implement an approval process for the ...
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2answers
38 views

Ensuring data quality from organizations

You are working for an organization that receives data from other organizations in different data formats (geospatial files, spreadsheets, text files, etc.) Is there specific things you would ask ...
4
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1answer
492 views

How can I parse modis MOD13Q1 quality layers in R?

I'd like to parse MOD13Q1 VI quality layers in R. My original code must have been incorrect, because it gave lots of "deep ocean" flags in the middle of Brazil. After the changes suggested by ...
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0answers
33 views

Collecting shapefiles from different users - any rules for quality data/quality control?

Apologies in advance for this very basic question! My company collects market information from forestry projects in an annual survey. This year, we are trying to add a spatial element to our ...
2
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2answers
217 views

Why OSM data has different attribute values from the same element and same time frame?

Here is my question: Does anyone know why OSM has different attribute values from the same element and same frame time? The example explains itself, when I try the Shapefile from different mirrors ...
2
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2answers
113 views

What are the ways we can control the quality of a DTM?

I imagine that for DTM obtained from Stereoscopic procedures or interpolation from a set of topographic points a comparaison with the original data can help, but what for DTM obtained from Remote ...
9
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1answer
191 views

What PostGIS [topology] provided tools may be used for data quality assurance?

I'm learning about techniques to ensure GIS data quality. Googling around, I've found a few papers about theory and best practices (here and here), and a couple of short presentations about the topic ...
0
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1answer
206 views

Utility GIS - Type of data cleanup needed & Effort

I am trying to get into Utility GIS and I have been asked by my boss to size up the effort of what it takes to clean up Pipeline, Utility asset GIS data and figure out if there is a way think of a ...
5
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2answers
330 views

How to check if Waste-Water Manhole connect to lines with the right flow direction?

I have a waste-water geometric network with flow direction throw digitize direction. I want to check if each manhole have a line flowing in and a line flowing out. Is there an attribute of line vertex ...
2
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1answer
340 views

Using line of sight or something similar to identify where lines go through hills

When QCing power infrastructure I am having to zoom into every gap and check to make sure the line makes sense (not going through the mountain). I typically check for odd spacing between the pylons ...
2
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1answer
520 views

Validating Values in Multiple Fields in an Attribute Table

I've been playing around with 'Maintaining Attribute Integrity' functions found here: http://resources.arcgis.com/en/help/...000000n000000/ I see how I can set domains and subtypes to control the ...
1
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1answer
168 views

Running a QC check for gaps between vertices on a polyline

I'm checking polylines to make sure power pylons were correctly extracted from imagery. Is there a way to find all of the gaps or missed pylons in the database? Currently, I'm manually making a ...
4
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1answer
803 views

Automated quality control and assurance - geodata?

I've recently started looking at the issue of automated quality control and assurance of geographic data. What software exists that can be used for accomplishing this? Esri has got their product ...
3
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0answers
164 views

Is there a tool for automated quality assurance for vector data captured on raster data? [closed]

I wonder whether is any tool(or script) in ArcGIS or QGIS which allows to make an automated quality assurance for vector data captured on raster data? vector data on binary raster:
9
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3answers
692 views

How do I compare two maps to determine which is better?

I'm trying to do an objective comparison of two different maps for the same region. At the moment, I'm struggling with defining criteria that will allow me to do a dispassionate evaluation. Does ...
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2answers
97 views

How to query points that fall outside their designated regions?

I have a shapefile with 250 points. Each point has a region attribute. In another shapefile I have all the possible regions with their names (it is polyline geometry). Unfortunately the coordinates ...
5
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3answers
266 views

Methods for lat/lon quality control?

I have a database with fields including latitude, longitude, city, state, and country. When mapped, it is clear that a number of the sites are in the wrong location - most commonly because of a sign ...