Blog d’Anita Graser

https://anitagraser.com

  • 27 novembre 2021New MovingPandas website
    The last couple of days, I have been hacking away to improve the online presence of MovingPandas. The new home page aims to be the central landing page that provides direct links to all important resources: from source code on Github, to documentation on ReadTheDocs, and – most importantly – all the tutorial and analysis example notebooks: Additionally, all tutorial and analysis example notebooks now contain direct links to live versions on MyBinder, sources on Github and already executed pre-rendered HTML versions of the notebooks for quick browsing: If you are using MovingPandas, I’d love to hear about it, particularly if you want to share one of your analysis examples with the community. …
  • 12 novembre 2021Open source for open spatial data science

    Thanks to the FOSS4G2021 video team, all talks including my keynote are now available online.

    I had the honor to be invited to give the closing keynote, talking about how open source can help open science, particularly data science:

    [youtube https://www.youtube.com/watch?v=ZjXb53pOor0?version=3&rel=1&showsearch=0&showinfo=1&iv_load_policy=1&fs=1&hl=en&autohide=2&wmode=transparent&listType=playlist&list=PLJUR-WK2_HcU_ycS_uXFTmnOFlyNvRngL&w=545&h=307]

    I’m convinced that efforts towards more open data science are a worthwhile investment even if current scientific incentive structures are stacked against it.

    Until incentive policies catch up, we all can help encourage more people to go the extra mile(s) by properly valuing their efforts, e.g. by celebrating and citing reproducible publications, open research datasets, and open scientific software.

  • 1 novembre 2021Exploring ZAMG’s new open weather data
    The Central Institution for Meteorology and Geodynamics (ZAMG) is Austrian’s meteorological and geophysical service. And as such, they have a large database of historical weather data which they have now made publicly available, as announced on 28th Oct 2021: Ab sofort sind hochwertige #Wetter–#Daten der ZAMG für zahlreiche Wetterstationen Österreichs seit Messbeginn kostenlos abrufbar (im Rahmen der Public Sector Information Richtlinie der #EU). Infos und Zugang auf https://t.co/TEArms2sNR— zamg.at (@ZAMG_AT) October 28, 2021https://platform.twitter.com/widgets.js The new ZAMG Data Hub provides weather and station data, mainly in NetCDF and CSV formats: I decided to grab a NetCDF sample from their analysis and nowcasting system INCA. I went with all available parameters for a period of one day (the data has a temporal resolution of one hour) and a bounding box around Vienna: https://frontend.hub.zamg.ac.at/grid/d512d5b5-4e9f-4954-98b9-806acbf754f6/historical/form?anonymous=true The loading screen of QGIS 3.22 shows the different NetCDF layers: After adding the incal-hourly layer to QGIS, the layer styling panel provides access to the different weather parameters. We can switch bet …
  • 1 novembre 2021MovingPandas v0.8 released!
    The latest v0.8 release is now available from conda-forge. New features include: More convenient creation of TrajectoryCollection objects from (Geo)DataFrames (#137)Support for different geometry column names (#112) Last week, I also had the pleasure to speak about MovingPandas at Carto’s Spatial Data Science Conference SDSC21: [youtube https://www.youtube.com/watch?v=c4WeKBjgNK4?version=3&rel=1&showsearch=0&showinfo=1&iv_load_policy=1&fs=1&hl=en&autohide=2&wmode=transparent&w=545&h=307] As always, all tutorials are available from the movingpandas-examples repository and on MyBinder: …
  • 28 septembre 2021Movement data in GIS #37: “Understanding Movement Data” webinar

    Two weeks ago, I had the pleasure to speak at SystemX’s seminar series. The talk features a live demonstration of my protocol for exploring movement data, powered by Jupyter, Pandas, Holoviews, Datashader, GeoPandas, and MovingPandas. So if you haven’t read the paper yet, here’s the chance to watch the talk version:

    [youtube https://www.youtube.com/watch?v=cGjUUGiates?version=3&rel=1&showsearch=0&showinfo=1&iv_load_policy=1&fs=1&hl=en&autohide=2&wmode=transparent&w=545&h=307]
  • 25 septembre 2021Exploring Vienna’s street-level Lidar “Kappazunder” data sample
    Kappazunder is the city of Vienna’s database created during their recent mobile mapping campaign. Using vehicle-mounted Lidar and cameras, they collected street-level Lidar and street view images. Slide from the official announcement on Thursday, 23rd Sept 2021. Full slide deck: https://www.slideshare.net/DigitalesWien/kappazunder-testdatensatz-2020-ogd-wien Yesterday, they published a first sample dataset, containing one trajectory on data.gv.at. The download contains documentation, vector data (.shp), images (.jpg), and point clouds (.laz): Trajectory The shapefiles contain vehicle location updates, photo locations, and areas describing the extent of the point clouds. Since the shapefile lack .prj files, we need to manually specify the correct CRS (EPSG:31256 MGI / Austria GK East). The vehicle location updates and photo locations contain timestamps as epoch. However, the format is a little special: To display a human-readable timestamp, I therefore used the following label expression: format_date( datetime_from_epoch( « epoch_s »*1000), ‘HH:mm:ss’) Adding these labels also reveals that the whole trajectory is just 2 minutes long. This puts the download size of over 5GB into perspe …
  • 15 septembre 2021Movement data in GIS #36: trucks from space
    Can we reliably measure truck traffic from space? Compared to private transport, spatiotemporal data on freight transport is even harder to come by. Detecting trucks using remote sensing has been a promising lead for many years but often required access to pretty specialized sensors, such as TerraSAR-X. That is why I was really excited to read about a new approach that detects trucks in commonly available Sentinel-2 imagery developed by Henrik Fisser (Julius-Maximilians-University Würzburg, Germany). So I reached out to him to learn more about the possibilities this new technology opens up.  Vehicles are visible and detectable in Sentinel-2 data if they are large and moving fast enough (image source: ESA) To verify his truck detection results. Henrik had already used data from truck counting stations along the German autobahn network. However, these counters are quite rare and thus cannot provide full spatial coverage. Therefore we started looking for more complete reference data. Fortunately, Nikolaus Kapser at the Austrian highway corporation ASFINAG offered his help. The Austrian autobahn toll system is gantry-based. It records when a truck passes a gantry. Using the timestamp o …
  • 28 juillet 2021Great label callout lines
    One of the new features in QGIS 3.20 is the option to trim the start and end of simple line symbols. This allows for the line rendering to trim off the first and last sections of a line at a user configured distance, as shown in the visual changelog entry.  This new feature makes it much easier to create decorative label callout (or leader) lines. If you know QGIS Map Design 2, the following map may look familiar – however – the following leader lines are even more intricate, making use of the new trimming capabilities: To demonstrate some of the possibilities, I’ve created a set of four black and four white leader line styles: You can download these symbols from the QGIS style sharing platform: https://plugins.qgis.org/styles/101/ to use them in your projects. Have fun mapping! …
  • 27 juin 2021QGIS Atlas on steroids
    Today’s post is a video recommendation. In the following video, Alexandre Neto demonstrates an exciting array of tips, tricks, and hacks to create an automated Atlas map series of the Azores islands. Highlights include: 1. A legend that includes automatically updating statistics 2. A way to support different page sizes 3. A solution for small areas overshooting the map border You’ll find the video on the QGIS Youtube channel: [youtube https://www.youtube.com/watch?v=NCsnTt6uxXo?version=3&rel=1&showsearch=0&showinfo=1&iv_load_policy=1&fs=1&hl=en&autohide=2&wmode=transparent&w=545&h=307] This video was recorded as part of the QGIS Open Day June edition. QGIS Open Days are organized monthly on the last Friday of the month. Anyone can take part and present their work for and with QGIS. For more details, see https://github.com/qgis/QGIS/wiki#qgis-open-day …
  • 4 juin 2021MovingPandas v0.7 released!
    The latest v0.7 release is now available from conda-forge. New features include: Functions to convert Trajectories to GeoDataFrames (points, line segments, or whole trajectories)Clip and intersection now return TrajectoryCollection objects As always, all tutorials are available from the movingpandas-examples repository and on MyBinder: …