Maxar usage over the last year
Zapsal pnorman 8. 7. 2023 v jazyce English. Naposledy aktualizováno 9. 7. 2023I was curious about the usage of Maxar over the last year, so did some quick work to see where it was used. To start, I used a Python 3 version of ChangesetMD to load the latest changesets into PostgreSQL, using the -g
option to create geometries.
I then, with a bit of manual work, identified the changesets of the last year are those between 122852000 and 137769483. Using this, and knowledge of tags normally used with maxar, I created a materialized view with just the Maxar changesets
CREATE MATERALIZED VIEW maxar AS
SELECT id,
num_changes,
st_centroid(geom)
FROM osm_changeset
WHERE id BETWEEN 122852000 and 137769483
AND (tags->'source' ILIKE '%maxar%' AND tags->'imagery_used' ILIKE '%maxar%');
This created a table of 2713316 changesets, which is too many to directly view, so I needed to get it by country.
I did this with the border data from country-coder
curl -OL 'https://raw.githubusercontent.com/rapideditor/country-coder/main/src/data/borders.json'
ogr2ogr -f PostgreSQL PG:dbname=changesetmd borders.json
This loaded a quick and dirty method of determining the point a country is in into the DB, allowing me to join the tables together
SELECT COALESCE(iso1a2, country), COUNT(*)
FROM maxar JOIN borders ON ST_Within(maxar.st_centroid, borders.wkb_geometry)
GROUP BY COALESCE(iso1a2, country)
ORDER BY COUNT(*) DESC;
coalesce | count |
---|---|
IN | 253789 |
ID | 138214 |
TR | 131282 |
BR | 121062 |
SV | 102280 |
GT | 100412 |
TZ | 86890 |
RU | 71243 |
US | 69600 |
BD | 60622 |
ZM | 60130 |
CN | 58226 |
NG | 55355 |
SY | 49353 |
PH | 46432 |
CD | 45216 |
AE | 40728 |
MW | 40710 |
PE | 37037 |
SE | 33762 |
UA | 33664 |
MX | 33012 |
HN | 32385 |
NP | 31692 |
KE | 30045 |
MY | 27224 |
RO | 26477 |
MG | 24456 |
ZA | 24262 |
CO | 23876 |
BY | 20925 |
AR | 20264 |
VN | 20203 |
GB | 19687 |
DE | 19613 |
UG | 19534 |
LY | 18980 |
KZ | 18037 |
TH | 17879 |
SA | 17270 |
PK | 17161 |
EG | 16848 |
ET | 16406 |
AU | 16134 |
IQ | 15819 |
AF | 15404 |
IT | 15283 |
SO | 14745 |
SD | 14346 |
CA | 14223 |
EC | 13919 |
ML | 13417 |
QA | 12379 |
CL | 11902 |
HU | 11284 |
IR | 10899 |
TG | 10533 |
TL | 10364 |
This usage includes a period of time at the end where Maxar was not working, which is still the case. It’s also a very quick and dirty method designed to minimize the amount of time I had to do stuff, at the cost of spending more computer time. ChangesetMD is unmaintained and loading all the changesets is slow, but I already knew how to use it, so it didn’t take me much time.
Diskuse
Komentář od Minh Nguyen z 8. 07. 2023 v 06:25
Thanks for running these numbers. It helps to get a sense of where the missing imagery will be most acutely felt. Another measure of that would be the countries with the greatest share of Maxar-based changesets out of the total number of changesets.
Komentář od Stereo z 8. 07. 2023 v 15:36
@Minh I had the same idea for the measure, and have commented here:
https://community.openstreetmap.org/t/maxar-imagery-not-working-was-maxar-is-blurred-in-id-and-other-similar-topics/100524/42
Komentář od PierZen z 10. 07. 2023 v 18:37
@pnorman revision to find ‘%maxar%’ in either the source or imagery_used : ((tags->’source’ ILIKE ‘%maxar%’) OR (tags->’imagery_used’ ILIKE ‘%maxar%’))