From 360f33590156d42059b0e61c646cba4f8b52d14d Mon Sep 17 00:00:00 2001 From: Stephen Mather <1174901+smathermather@users.noreply.github.com> Date: Mon, 15 Apr 2024 12:26:07 -0400 Subject: [PATCH 1/5] Update large.rst to include flying time estimates --- source/large.rst | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) diff --git a/source/large.rst b/source/large.rst index b168b9c81..2efcaf926 100644 --- a/source/large.rst +++ b/source/large.rst @@ -193,6 +193,29 @@ The 3D textured meshes are currently not being merged as part of the workflow (o GCPs are fully supported, however, there needs to be at least 3 GCP points on each submodel for the georeferencing to take place. If a submodel has fewer than 3 GCPs, a combination of the remaining GCPs + EXIF data will be used instead (which is going to be less accurate). We recommend using the ``image_groups.txt`` file to accurately control the submodel split when using GCPs. +Estimating data collection effort +--------------------------------- + +Larger datasets can be collected with specialized fix wing UAVs, vertical takeoff and landing (VTOL) UAVs, and collected quite efficiently under certain conditions. In many instances, however, we are constrained to doing data collection efforts with commodity quadcopters. In these cases, a common question is the data collection time under ideal conditions with commodity equipment. + +Data collection effort, full 3D +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +For best in class results with full 3D reconstruction and 5cm resolution, it is feasible to collect 1-2km\ :sup:`2`. This requires the following set of flights: +* 60% overlap nadir flight +* 70-80% overlap 45-degree gimbal angle cross grid + +Data collection effort, 2D and 2.5D products +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +For best in class results 2D and 2.5D products and 5cm resolution, it is feasible to collect 2-4km\ :sup:`2`. This requires the following set of flights: +* 70-80% overlap slightly off-nadir (5-10 degree off nadid) + +For more complex buildings and vegetation, aim for closer to 80% overlap. If buildings, vegetation, and terrain changes are not complex, it's quite feasible to use closer to 70% overlap. + +(credit: derived from ongoing conversations with Ivan Gayton, Humanitarian OpenStreetMap Team) + + Acknowledgments --------------- Huge props to Pau and the folks at Mapillary for their amazing contributions to OpenDroneMap through their OpenSfM code, which is a key component of the split-merge pipeline. We look forward to further pushing the limits of OpenDroneMap and seeing how big a dataset we can process. From 494dca3a731ee95e16a18b611edd83cec6d67d2a Mon Sep 17 00:00:00 2001 From: Stephen Mather <1174901+smathermather@users.noreply.github.com> Date: Mon, 15 Apr 2024 12:27:42 -0400 Subject: [PATCH 2/5] fix bullets --- source/large.rst | 2 ++ 1 file changed, 2 insertions(+) diff --git a/source/large.rst b/source/large.rst index 2efcaf926..a308e278a 100644 --- a/source/large.rst +++ b/source/large.rst @@ -202,6 +202,7 @@ Data collection effort, full 3D ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ For best in class results with full 3D reconstruction and 5cm resolution, it is feasible to collect 1-2km\ :sup:`2`. This requires the following set of flights: + * 60% overlap nadir flight * 70-80% overlap 45-degree gimbal angle cross grid @@ -209,6 +210,7 @@ Data collection effort, 2D and 2.5D products ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ For best in class results 2D and 2.5D products and 5cm resolution, it is feasible to collect 2-4km\ :sup:`2`. This requires the following set of flights: + * 70-80% overlap slightly off-nadir (5-10 degree off nadid) For more complex buildings and vegetation, aim for closer to 80% overlap. If buildings, vegetation, and terrain changes are not complex, it's quite feasible to use closer to 70% overlap. From e770380e4fbcc58abdfebbc7a168ee4865458915 Mon Sep 17 00:00:00 2001 From: Stephen Mather <1174901+smathermather@users.noreply.github.com> Date: Mon, 15 Apr 2024 12:28:31 -0400 Subject: [PATCH 3/5] per person per day --- source/large.rst | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/source/large.rst b/source/large.rst index a308e278a..5dbfdaf28 100644 --- a/source/large.rst +++ b/source/large.rst @@ -201,7 +201,7 @@ Larger datasets can be collected with specialized fix wing UAVs, vertical takeof Data collection effort, full 3D ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ -For best in class results with full 3D reconstruction and 5cm resolution, it is feasible to collect 1-2km\ :sup:`2`. This requires the following set of flights: +For best in class results with full 3D reconstruction and 5cm resolution, it is feasible to collect 1-2km\ :sup:`2` per person, per day. This requires the following set of flights: * 60% overlap nadir flight * 70-80% overlap 45-degree gimbal angle cross grid @@ -209,7 +209,7 @@ For best in class results with full 3D reconstruction and 5cm resolution, it is Data collection effort, 2D and 2.5D products ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ -For best in class results 2D and 2.5D products and 5cm resolution, it is feasible to collect 2-4km\ :sup:`2`. This requires the following set of flights: +For best in class results 2D and 2.5D products and 5cm resolution, it is feasible to collect 2-4km\ :sup:`2` per person, per day. This requires the following set of flights: * 70-80% overlap slightly off-nadir (5-10 degree off nadid) From 21ce8716b732ca46693d29179aadafb0082a99cd Mon Sep 17 00:00:00 2001 From: Stephen Mather <1174901+smathermather@users.noreply.github.com> Date: Mon, 15 Apr 2024 12:35:38 -0400 Subject: [PATCH 4/5] nadid to nadir --- source/large.rst | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/source/large.rst b/source/large.rst index 5dbfdaf28..b4fb13d9f 100644 --- a/source/large.rst +++ b/source/large.rst @@ -211,7 +211,7 @@ Data collection effort, 2D and 2.5D products For best in class results 2D and 2.5D products and 5cm resolution, it is feasible to collect 2-4km\ :sup:`2` per person, per day. This requires the following set of flights: -* 70-80% overlap slightly off-nadir (5-10 degree off nadid) +* 70-80% overlap slightly off-nadir (5-10 degree off nadir) For more complex buildings and vegetation, aim for closer to 80% overlap. If buildings, vegetation, and terrain changes are not complex, it's quite feasible to use closer to 70% overlap. From 54b143ac6d2131e434f18f6c2796976124d49832 Mon Sep 17 00:00:00 2001 From: Stephen Mather <1174901+smathermather@users.noreply.github.com> Date: Sun, 25 Aug 2024 16:46:04 -0400 Subject: [PATCH 5/5] Explain nadir/oblique overlap logic --- source/large.rst | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/source/large.rst b/source/large.rst index c228523b0..de8fdff01 100644 --- a/source/large.rst +++ b/source/large.rst @@ -204,7 +204,9 @@ Data collection effort, full 3D For best in class results with full 3D reconstruction and 5cm resolution, it is feasible to collect 1-2km\ :sup:`2` per person, per day. This requires the following set of flights: * 60% overlap nadir flight -* 70-80% overlap 45-degree gimbal angle cross grid +* 70-80% overlap 45-degree gimbal angle cross-grid + +The 45-degree cross-grid flight provides the basis for a fully tied together model, while the nadir flights provide the necessary texture for orthophoto texturing. The lower overlap meets the minimum requirement for orthophoto products as facilitated by by feature matching from the much higher overlap cross-grid. Data collection effort, 2D and 2.5D products ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^