Review of satellite remote sensing and unoccupied aircraft systems for counting wildlife on land
Creators: name: ATTARD, MARIE R.G.
Publisher: name: Zenodo
Year: 2024

description: Supplementary material from Remote Sensing review article titled "Review of Satellite Remote Sensing and Unoccupied Aircraft Systems for Counting Wildlife on Land". This consists of 5 tables, as described below: 

Table S1. Commercial high-resolution satellites that can detect objects less than one metre. Image resolution is measured as Ground Sampling Distance (GSD), the distance between two consecutive pixel centres measured on the ground in metres. The information was collated in November 2023 using the ESA eoPortal [1], CEOS database [2], OSCAR database [3], Satellite Imaging Corporation database [4] or through direct correspondence with the provider. The launch date, mission status in 2023, and expected end of life (EOL) is reported, including EOL to be determined (TBD). Mission status is classified as planned (upcoming launch planned), operational (all systems fully working) and decommissioned (no longer functional)

Table S2. Commercial synthetic-aperture radar (SAR) satellites that can detect objects smaller than one metre. The information was collated in November 2023. Image resolution is measured as Ground Sampling Distance (GSD), the distance between two consecutive pixel centres measured on the ground in metres. ICEYE is currently a constellation of 21 satellites, with plans for expansion to 48 satellites by 2024. The Italian Space Agency (ASI)’s COnstellation of small Satellites for Mediterranean basin Observation (COSMO-SkyMed) is part of The European Space Agency (ESA) Third Party Missions Programme, in which ESA has an agreement with ASI to distribute data products from the mission. The first-generation COSMO-SkyMED (CSK) satellites consist of four satellites and the second Generation of COSMO-SkyMed (CSG) satellites consist of two satellites (CSG-1 and CSG-2) with sub-1m resolution capabilities and are in the same orbit.

Table S3. Comparison of costs between commercial synthetic-aperture radar (SAR) satellites that can detect objects smaller than one metre. The order requirements for tasked and archival imagery differ for each company. Costing is dependent on multiple parameters, including minimum area and whether archival/tasked imagery. Image resolution is measured as Ground Sampling Distance (GSD) for square pixels (i.e., the distance between two consecutive pixel centres measured on the ground in metres) or Maximum Ground Resolution (MGR) for rectangular pixels (measured as azimuth x range). SAR satellites can image in different modes; spotlight and sliding spotlight modes produce higher resolution images. Spotlight imaging is when a beam is focused on a single point of Earth through the acquisition, whereas in sliding spotlight, the acquisition angle is slowly varied to slide the illumination point along the ground to cover a larger area [1]. The Italian Space Agency have Cosmo-Skymed (CSK) and Cosmo Second Generation (CSG) SAR satellites. The UMBRA single-looked product offers shorter dwell times, optimised for very efficient and dense collection, whereas the multi-looked product has longer dwell times to reduce speckle and aid visual interpretation. Umbra SAR satellite constellations are Umbra SAR-2001, Umbra-02, Umbra-03, Umbra-04, Umbra-05 and Umbra-06. Capella Space satellite imagery products are available for purchase from Cloud Earth Observation Services (CLEOS) [12].

Table S4. Comparison of costs between commercial satellite companies that provide imagery per square km for a minimum order. Planet provides imagery based on annual subscriptions (see main text for details). Each company has different order requirements for tasked and archival imagery, with the costs dependent on multiple parameters, including minimum area. Image resolution is measured as Ground Sampling Distance (GSD), the distance between two consecutive pixel centres measured on the ground in metres.

Table S5. Examples of successful crowdsourcing campaigns to estimate population size of wildlife on land using VHR satellite remote sensing (SRS) and unoccupied aircraft systems (UAS). The campaigns are listed in order of release date. The platform Tomnod has been replaced by GeoHIVE.