SW Maps for Low-Cost GNSS Receiver Systems

SW Maps for Low-Cost GNSS

Receiver Systems

Presented by Dinesh Manandhar, The University of Tokyo on behalf of

Avinab Malla

Space System Applications and Geospatial Engineering, Nepal

avinabmalla@yahoo.com

SW Maps

•Free Android Application

•For collecting, presenting and

sharing geographic information

• More than 140,000 downloads

• As of June 2019

• Large scale GNSS surveys

possible

SW Maps Features

• Collect GIS data using internal and external

GNSS receivers

• Bluetooth or USB

• Connect RTK capable receivers for high accuracy

surveying.

• Import and display popular GIS Data formats

• KML, Shapefiles, GeoJSON, Mbtiles, GeoPackage

• Export or share collected data directly to

• KMZ, Shapefiles, GeoJSON, GeoPackage and

many other formats.

• Record tracks and geo-tagged photos

More Features

• Define and record multiple feature layers

• Google Maps or OpenStreetMap as background

• Can also import and cache maps from online sources

(WMS, XYZ Tiles)

• View Shapefiles

• with attribute categorized styling.

• Draw features on map

• Measure distance and area on Map

• Share projects and templates with other users.

Drone Imagery Mbtiles Shapefile Categorized Styling

Exported KMZ in Google Earth

SW Maps Templates

• Projects once created can be

exported as a template for other

projects.

• Useful when many surveyors and

instruments are deployed to collect

the same type of data

• Templates can be made on a

Windows PC using the SW Maps

Template Builder tool, or exported

from any existing project using SW

Maps

RTK Surveying With SW Maps

•SW Maps can be used with RTK

capable receiver through

Bluetooth or USB

Low-Cost GNSS Receivers for SW Maps

• USB Connection

• Costs approx. US $ 150

• Bluetooth + Wi-Fi Connection

• Internal Rechargeable Battery, Lasts 12 Hours

• Micro-SD Card Slot for data recording

• 3D-Printed Enclosure

• Costs approx. US$ 400

Low-Cost RTK with RtkDroid

• Low cost receivers do not have an in-built

RTK capability

• The Android app RtkDroid was created for

RTK positioning

• Currently UBX file from M8T

• Near Future, UBX file from F9P, F9T and MADOCA

• RtkDroid uses correction data from NTRIP

casters (in RTCM3 format)

• VRS is also available

• RtkDroid is based on RTKLIB

Post Processed Kinematic (PPK) with SW Maps

• Useful for places with unreliable internet

connection

• SW Maps can log Raw GNSS observations

when using an external receiver.

• Recorded files are exported with the project

and can be used for post-processing

• Automatic tool has been developed for

correcting recorded data points using CORS

station in Kathmandu

Kathmandu Reference Station

Low-Cost RTK Receiver

SW Maps Applications

SW Maps used by IOM Bangladesh - Needs and Population Monitoring

SW Maps Use for 2020 Census in Indonesia

https://www.unescap.org/sites/default/files/Session8_Use_of_geospatial_during_enumeration_Indonesia_Census_WS_24-26Jan2018.pdf

SW Maps Use for 2020 Census in Indonesia

SW Maps Training by Bhutan GIS Society

Construction Monitoring of Water Supply Works in Kathmandu Valley

SW MAPS used for Data Capture

• Web Based System with open source software

• Centralized PostgreSQL Database

• Web Interface for Data Query and Geometry Editing

• Details of Construction Progress

• Map Overlay

http://wnms.softavi.com

• SW MAPS was used for Survey of

completed and ongoing works

• Uploading to server with

photographs

Sewerage Network Asset Condition Assessment and GIS Survey

Total Covered=117 SqKm

Total Manhole Surveyed: 52,566

Sewer Line: 1,201 Km

SW MAPS used for Data Capture

• Customized SW MAPS system for tablet

for onsite data entry and photographs

• Automated uploading to server with

photographs

• Automated Server Data Update

Sewer Asset Management System

• Web Based System

with open source

software

• Centralized Database

• Web Interface for Data

Query and Editing

• Sewer Profile and

Manhole Details

• Map Overlay

Survey using RTK GPS

Application

• Sewer Maintenance Management

• Public portal for sewer maintenance

request

• Asset Management

• Sewer network expansion

http://sams.softavi.com

Community Water Supply Information

Total Covered 5 Districts of Nepal

SW MAPS used for Data Capture

• SW MAPS was used for Survey of

completed water supply works

• Survey of unserved Community and

potential water sources

• Uploading to server with photographs

• Web Based System with open source

software

• Centralized PostgreSQL Database

• Web Interface for Data Query and

Geometry Editing

• Details of Water Supply Projects

http://careims.softwel.com.np

Small Irrigation Project

Total Covered = 9 Districts Total

Project Surveyed: 1200 (till now)

SW MAPS used for Data Capture

• SW MAPS was used for Survey

works.

• Uploading to server with photographs

• Editing of Geometries in Server

• Web Based System with

open source software

• Centralized PostgreSQL

Database

• Web Interface for Data

Query and Geometry

Editing

• Irrigation Details

• Map Overlay

http://sipnepal.org

Future Plans

• Precise RTK/DGPS positioning using internal GNSS receiver of

smartphones

• Using Android raw GNSS API

• Add support for exporting data in regional coordinate systems

• Improve application performance for very large projects

• > 10000+ survey points

More Information

SW Maps on the Google Play Store

https://play.google.com/store/apps/details?id=np.com.softwel.swmaps

SW Maps Template Builder

http://swmaps.softwel.com.np/template_builder

SW Maps user manual

http://swmaps.softwel.com.np/assets/resources/manual.pdf

RtkDroid Demo

https://www.youtube.com/watch?v=Z_C33io_8S4