Water Resource Management – Drone Mapping and AquaBits

JP Uncategorized

DroneMapper recently mapped a mid-sized reservoir, Hotel Twin Lake, located on the top of the Grand Mesa in Colorado, USA. Figure 1 shows a Google image of the lake at full capacity:



Hotel Twin was drained to its deadpool prior to our drone imagery collection and placement of aerial targets for mapping and ground surveying. 342 images were acquired using a Phantom 3 Advanced drone and six (6) aerial targets or Ground Control Points (GCPs) were precisely ground surveyed for XYZ locations. The imagery and GCPs were processed using REMOTE EXPERT software. Figure 2 illustrates the DEM with GCPs constructed of the reservoir basin:



The ground survey of the GCPs was performed using a Trimble GPS/RTK 5800 Base and Rover communicating over a 25-watt UHF Trimble radio (TrimMark 3). The GCP ground surveyed elevations were compared to the elevations measured on the DEM and are shown in Table 1:



Using Global Mapper GIS software (Blue Marble Geographics, Hallowell Maine) 1-foot contours were generated from the gate valve invert (reservoir’s drain) up to spill. Figure 3 illustrates the DEM with contours superimposed:



Reservoir storage capacity (acre-feet) was computed for each 1-foot contour. The data was fit to a 3rd-order polynomial as shown in the following Figure 4 plot:



The coefficient of determination, R2, indicates an exceptionally good fit with the 3rd-order polynomial model. You may be asking “what do you do with the polynomial model?” Topic of next discussion -

AquaBits – Real Time Monitoring of Water Resources

AquaBits is an accurate water resource monitor measuring/reporting gage height of reservoirs and open channels in real time. Water gage height is measured using an immersible hydrostatic pressure, industrial grade sensor. AquaBits reads the sensor at prescribed intervals and sends the measurement using either cellular or satellite communication modems to our aquabits.io web site within 1-minute of data acquisition. Figure 5 illustrates an AquaBits installation for an open channel application:



AquaBits is shown to the left with Colorado state instruments to the right. For Hotel Twin Lake AquaBits was mounted to an existing steel support structure as shown in Figure 6:



The water sensor is run from the electronics box (just below the solar panel) to the reservoir’s gate valve invert or drain. For this application AquaBits reports every 6-hours and the stored capacity as a function of water elevation is computed using the previously described polynomial model. The lake’s location is remote with no cellular service dictating the use of a satellite modem for data transfer to aquabits.io. Figure 7 shows recent July 2021 data from aquabits.io indicating a slow growth of storage capacity over a couple of days.



This type of data is particularly useful to understand water ingress, discharge, lake evaporation and possibly predict reservoir’s storage through winter and spring months prior to full thaw and start of the next irrigation season.

Special Equipment and Software Offer

DroneMapper has a hot July special equipment and software offering – a complete drone mapping system with Trimble ground survey and processing software including the following:

    • DJI Phantom 3 Advanced drone complete with Pelican roller case (see Figure 8):
      Less than 1 hour flight time on P3A (used as backup spare for our operations),
      Additional NIR modified camera (NIR,G,B) used for crop health monitoring,
      Value estimated at $500-1,000 (used)


    • Trimble GPS RTK 5800 Base, Rover and UHF Radio complete, housed within two cases (see Figures 9 & 10):
      Base and Rover Receivers (batteries/charger included),
      TSC Controller (battery/charger included),
      2-10-25-watt, 450-470 MHz Radio (battery not included)
      All cables and antennas,
      Value estimated at $3,000-4,000 (used)




    • Perpetual license for REMOTE EXPERT photogrammetric processing software:
      Produce DEMs, orthos, point clouds, with or without GCPs,
      License cost - $999

    • Complete precision mapping system offered at $3,500 plus shipping. All you need to add is the aerial targets, tripods and survey rods.

  • Thanks for looking at our blog and please contact us with any questions regarding mapping, AquaBits or our special. The very best for this summer and onwards!

    DroneMapper Photogrammetry Software Updates 2021

    JP Uncategorized

    We've been busy working on enhancements to the DroneMapper Photogrammetry Software package and a handful of exciting enterprise projects! Please take a look at the software changelog below for the latest updates and features. We always appreciate customer suggestions and feedback to improve our offerings. Please contact us anytime with your ideas!

    Thanks, DroneMapper Team

    February 10th, 2021 - v1.9.2 20210210
    • Customer suggested feature: change resolution of RGB orthomosaic preview. Default setting is 8x native GSD with new settings options for 4x GSD and 2x GSD. Allows rapid production of RGB preview orthomosaic in the field supporting disaster mapping and emergency operations.
    color orthomosaic
    January 22nd, 2021 - v1.9.1 20210122
    • Remove twitter icon/link from UI
    • Remove license clean exe (false flag as malware by anti-virus)
    November 26th, 2020 - v1.9.1 20201126
    • Bitcoin, Eth and other crypto payments accepted via coinbase.com
    • Enhance GPU tie point generator, performance optimizations
    November 4th, 2020 - v1.9.1 20201104
    • New tie point reduction algorithm. Useful for large datasets, imagery with large feature counts, or when using Brisk/Akaze/Multi-Scale TP. Algorithm filters and selects the best tie points based on score, limits tie points to a reasonable count per image pair. Speeds up large dataset processing.
    • Initial CUDA based tie-point detector and feature matching. Requires a NVIDIA GPU and driver >= 418.39 (beta), utilizes CPU and GPU CUDA cores.
      CUDA SDK: 10.1 (10.1.105) DRIVER >= 418.39 NVIDIA CUDA: Ver 10.1 - CUFFT CUBLAS NVIDIA GPU Archs: 30 35 37 50 52 60 61 70 75
    October 26th, 2020 - v1.9 20201026
    • Fix for GCP processing in Stereo/Per Image Matching mode
    • UI and about dialog updates
    • Update to latest exiftool v12.06

    AquaBits.io Cutting Edge Water Management Solutions

    JP Uncategorized

    aquabits sensor
    In the last few months DroneMapper has developed a terrestrial sensor (AquaBits IoT) focused on water resource management. This post describes our development, verification and capabilities for an affordable, real time device sensing flowing water in channels and continuous measurement of reservoir holding capacities. Previously we described the use of drone imagery collection, precision imagery processing and generation of reservoir basin contours from the DEM for water elevation correlation to storage capacity. This data can now be augmented with real time reporting of actual reservoir stage at any frequency of interest, with little latency to water managers.

    AquaBits utilizes accurate hydrostatic pressure measurement of the water column and is self contained inclusive of a power subsystem and communication capability using either cellular (when available) or satellite for remote locations. Data is transmitted to our secure dashboard where it is archived and processed for discharge in a flowing channel or current water stage in a reservoir. A slide deck with an overview of AquaBits and recently collected data compared to Colorado State instrumentation can be found here: (pdf attached)

    In other scenarios when equipped with the appropriate sensor(s), applications to consider may include soil nutrient/moisture measurement for agriculture, earth subsidence/movement, chemical contamination, water quality, audio/visual surveillance, limited only by the imagination... Feel free to contact us and discuss your specific application.

    The DroneMapper Team

    aquabits.io

    Lowering the Cost of Continuous Streamflow Monitoring Award, January 21, 2020

    JP Uncategorized

    The Bureau of Reclamation and the US Geological Survey conducted a challenge in 2019 to solicit approaches for the reduction of cost associated with streamflow monitoring at gaging sites throughout the US. "...continuous streamflow monitoring stations are vital to water resources planning, design, management and research." With budget and project priority pressures the number of gaging sites nationally is in decline.

    DroneMapper was one of five selected finalists in the challenge offering an approach using a 3D sensor for continuous remote sensing of the water surface and the use of UAS for stream channel characterization to improve hydrological modeling and simulation. The Bureau and USGS award press release is viewed here: https://www.usbr.gov/newsroom/stories/detail.cfm?RecordID=69224

    We are very interested in pursuing this technology further for US Government, state and local use. We are in the process of identifying investment alternatives that would promote further development and verification of the 3D sensor. Please do not hesitate to contact us if you have or know of someone that has an interest in supporting this venture. Please contact Pierre Stoermer, CEO DroneMapper, (970) 417-1102

    Many thanks from the DroneMapper Team!!

    Data Science Basic Crop Analysis with UAV Imagery and Micasense Altum

    JP Uncategorized

    https://github.com/dronemapper-io/CropAnalysis

    A jupyter notebook with crop analysis algorithms utilizing digital elevation models, dtm and multi-spectral imagery (R-G-B-NIR-Rededge-Thermal) from a MicaSense Altum sensor processed with DroneMapper Remote Expert.

    Due to limitations on git file sizes, you will need to download the GeoTIFF data for this project from the following url: https://dronemapper.com/software/DroneMapper_CropAnalysis_Data.zip. Once that has been completed, extract the TIF files into the notebook data directory matching the structure below.

    Included Data

    • data/DrnMppr-DEM-AOI.tif – 32bit georeferenced digital elevation model
    • data/DrnMppr-ORT-AOI.tif – 16bit georeferenced orthomosaic (Red-Green-Blue-NIR-Rededge-Thermal)
    • data/DrnMppr-DTM-AOI.tif – 32bit georeferenced dtm
    • data/plant_count.shp – plant count AOI
    • data/plots_1.shp – plot 1 AOI
    • data/plots_2.shp – plot 2 AOI
    • output/*.csv – output csv of dataframes

    Algorithms

    • plot volume/biomass
    • plot canopy height
    • plot ndvi zonal statistics
    • plot thermals
    • plant count

    Notes

    These basic algorithms are intended to get you started and interested in multi-spectral processing and analysis.

    The orthomosaic, digital elevation model, and dtm were clipped to an AOI using GlobalMapper. The shapefile plots were also generated using GlobalMapper grid tool. We highly recommend GlobalMapper for GIS work!

    We cloned the MicaSense imageprocessing repository and created the Batch Processing DroneMapper.ipynb notebook which allows you to quickly align and stack a Altum or RedEdge dataset creating the correct TIF files with EXIF/GPS metadata preserved. These stacked TIF files are then directly loaded into DroneMapper Remote Expert for processing.

    This notebook assumes the user has basic knowledge of setting up their python environment, importing libraries and working inside jupyter.

    Do More!

    Implement additional algorithms like NDRE or alternative methods for plant counts. Submit a pull request to the repo!

    Load Digital Elevation Model and Orthomosaic

    Orthomosaic-DigitalElevationModel

    Load Plot 1 AOI and Generate NDVI

    ndvi_zonal_statistics

    Generate NDVI Zonal Statistics For Each Plot

     ndvi_zonal_statistics_plots
    geometryLAYERMAP_NAMENAMEminmaxmeancountstdmedian
    0POLYGON Z ((289583.708 5130289.226 0.000, 2895…Coverage/QuadUser Created Features20.1884610.8730920.43855944440.0789210.436500
    1POLYGON Z ((289588.705 5130289.052 0.000, 2895…Coverage/QuadUser Created Features30.1932140.8879710.44528244400.0910900.425304
    2POLYGON Z ((289593.702 5130288.877 0.000, 2895…Coverage/QuadUser Created Features40.2322220.8901470.55286444400.1124400.519746
    3POLYGON Z ((289598.699 5130288.703 0.000, 2896…Coverage/QuadUser Created Features50.0908250.8650830.53029544440.1105700.515392
    4POLYGON Z ((289603.696 5130288.528 0.000, 2896…Coverage/QuadUser Created Features60.1046970.9224500.53666044420.1327310.495813

    Load Plot 2 AOI & Compute DEM Canopy Mean Height For Each Plot

     canopy_height_dem
    geometryLAYERMAP_NAMENAMEminmaxmeancountstdmedian
    0POLYGON Z ((289707.875 5130279.812 1182.502, 2…Coverage/QuadUser Created Features – Coverage/Quad1360.129120363.381683361.14129433181.091593360.441467
    1POLYGON Z ((289712.189 5130279.586 1190.569, 2…Coverage/QuadUser Created Features – Coverage/Quad2360.131866363.382446361.71029733161.215926361.927017
    2POLYGON Z ((289716.503 5130279.360 1183.212, 2…Coverage/QuadUser Created Features – Coverage/Quad3360.117279363.384766361.13859233101.122890360.425781
    3POLYGON Z ((289720.817 5130279.134 1182.668, 2…Coverage/QuadUser Created Features – Coverage/Quad4360.110443363.387207361.91543633221.258644362.585251
    4POLYGON Z ((289725.131 5130278.908 1182.782, 2…Coverage/QuadUser Created Features – Coverage/Quad5360.006683363.377991361.55850133201.305164360.546524

    Compute Thermal Mean For Each Plot

    The thermal band (5) in the processed orthomosaic shows stitching artifacts which could likely be improved using more accurate pre-processing alignment and de-distortion algorithms. You can find more information about these functions in the MicaSense imageprocessing github repository. See notes at the top of this notebook.

     
    geometryLAYERMAP_NAMENAMEminmaxmeancountstdmedian
    0POLYGON Z ((289707.875 5130279.812 1182.502, 2…Coverage/QuadUser Created Features – Coverage/Quad130008.030431.030196.6286923318120.98205830193.0
    1POLYGON Z ((289712.189 5130279.586 1190.569, 2…Coverage/QuadUser Created Features – Coverage/Quad230068.030560.030333.1927023316123.85609330332.0
    2POLYGON Z ((289716.503 5130279.360 1183.212, 2…Coverage/QuadUser Created Features – Coverage/Quad329792.030645.030266.0302113310170.83120730275.5
    3POLYGON Z ((289720.817 5130279.134 1182.668, 2…Coverage/QuadUser Created Features – Coverage/Quad429790.030700.030386.1372673322201.26691930391.0
    4POLYGON Z ((289725.131 5130278.908 1182.782, 2…Coverage/QuadUser Created Features – Coverage/Quad529618.030691.030209.9045183320292.29939230262.0

    Load Plot 1 AOI & Compute Volume/Biomass For Each Plot

    biomass
    geometryLAYERMAP_NAMENAMEminmaxmeancountsumvolume_m3area_m2
    0POLYGON Z ((289583.708 5130289.226 0.000, 2895…Coverage/QuadUser Created Features2-0.1534733.5255431.53252444446810.53848376.65036850.0
    1POLYGON Z ((289588.705 5130289.052 0.000, 2895…Coverage/QuadUser Created Features3-0.0944823.5752261.64666444407311.18869082.28502150.0
    2POLYGON Z ((289593.702 5130288.877 0.000, 2895…Coverage/QuadUser Created Features4-0.0706483.9924931.88459644408367.60827694.17467650.0
    3POLYGON Z ((289598.699 5130288.703 0.000, 2896…Coverage/QuadUser Created Features50.0329284.5759892.969443444413196.202637148.51891550.0
    4POLYGON Z ((289603.696 5130288.528 0.000, 2896…Coverage/QuadUser Created Features60.0741885.1054083.155879444214018.412506157.77261750.0

    Load Plant Count AOI & Count Plants

    plant_count
    plant_count
    Plant count: 310
    UTMXUTMY
    0289622.4111715130240.899705
    1289621.8497055130244.325966
    2289622.1015695130248.858655
    3289621.8650865130253.863387
    4289621.4362805130258.158493

    Thanks! Keep an eye out for future notebooks and algorithms.